Botanical Journal of the Linnean Socie!y (1982), 84: 329-353.

With 5 figures

The identification of coca (Erpthroxylum

species): 186M910

TIMOTHY PLOWMAN

Botany Department, Field Museum of Natural History,

Chicago, Illinois, 60605, U.S.A.

Received June 1981, accepted f o r publication October 1981

The taxonomic history of plants known under the name ‘coca’ is complex. During the period
1 8 W 1910, botanists, horticulturalists and pharmacists became increasingly interested in the varieties
of coca then known in cultivation. A debate over the correct identity of the cultivated cocas ensued
which continues today. During the latter part of the 19th century and early part of the 20th century,
several new taxa were described from cultivation which significantly .complicated the taxonomy.
Notable contributors were D. Morris in Kew, W. Burck in Bogor, H. H. Rusby in New York and 0.E.
Schulz in Berlin. In order to evaluate the complex interaction among these workers, it is necessary to
examine the problem chronologically. Two cultivated species of commercial coca are now recognized:
Erythroxylum coca Lam. and Eryfhroxylwn nooogranaftnre (Morris) Hieron., each of which has one distinct
variety in cultivation: E. coca var. ipadu Plowman and E. nouogranatense var. fruxilleme (Rusby)
Plowman, respectively.

KEY WORDS:--coca ~ cocaine ~ Erythroxylaceae - Eythroxylurn ~ pharmacognosy ~ taxonomy.

CONTENTS

Introduction . . . . . . . . . . . . . . . . . . . 329
The early period . . . . . . . . . . . . . . . . . . 33 I
The Kew plant . . . . . . . . . . . . . . . . . . 334
Java coca . . . . . . . . . . . . . . . . . . . . 336
The Rusby era. . . . . . . . . . . . . . . . . . . 341
Contributions of 0. E. Schulz . . . . . . . . . . . . . . . 346
Conclusion . . . . . . . . . . . . . . . . . . . 348
Acknowledgements. . . . . . . . . . . . . . . . . . 351
Appendix: Location and identity of herbarium specimens mentioned in the text . . . 351
References. . . . . . . . . . . . . . . . . . . . 352

INTRODUCTION
“It is doubtful if anyone ever wrote or approved
a definition of ‘coca’ without misgiving.”
H. H. Rusby (1900)
Until the middle of the nineteenth century, the identity of the cultivated coca
plant of South America was not disputed. All authors agreed that the plant
belonged to the species Erythroxylum coca Lam. (Lamarck, 1786) which was
described on the basis of collections made by Joseph de Jussieu in 1749 in the
329
0024-4074/82/040329 + 25 $03.00/0 0 1982 The Linnean Society of London
330 T. PLOWMAN

Figure 1. Photograph of the original drawing of the type collection of Eryfhro&m COCG Lam. made by
Joseph de Jussieu in 1749. Preserved at the Mustum National d’Histoire Naturelle, Paris.
 COCA 33 I

Yungas region of Bolivia (Fig. 1). Only Willdenow (1799), in describing a plant
which is now considered to belong to E . nouogranatenre (Morris) Hieron.,
recognized a second kind of coca at this early time, although he too placed it under
E. coca. However, as the coca leaf became better known, both through increased
exploration in the American tropics and because of growing interest in its
medicinal properties in Europe and North America, there arose a controversy
among botanists and pharmacognosists concerning the botanical identity of coca.
Commerce in coca leaf increased after 1884 when, after the publication of Uber
Coca by Freud (1884) and the rediscovery by Koller ( 1884) of the local anaesthetic
powers of cocaine, its stimulatory and anaesthetic properties became the centre of
interest in medical circles. Merchants, pharmacists and physicians became
increasingly concerned about the different physical and chemical properties they
observed in different kinds of commercial coca leaves. In addition, coca was being
planted experimentally both as a potential cash crop and as an ornamental plant
in many of the former European colonies in the tropics. Changes observed when
the plants were cultivated in these areas further contributed to the taxonomic
confusion.
Over a period of about 50 years, from the early 1860s, many workers queried
the identity of coca. Most authors who wrote about coca contributed little to
resolving the taxonomic problems and only perpetuated past errors by copying,
often incorrectly, from previous works. Some workers, such as Burck (1890, 1892)
in Java, attempted to tackle the problem from distant outposts, where no
comparative herbarium specimens and little botanical literature were available.
Others, like Rusby (1886, 1888, 1900, 1901) and Schneider (1898) in the U.S.A.,
were trained mainly in medicine and pharmacognosy and lacked the necessary
background for understanding complex taxonomic matters. These workers created
more problems than they solved by not following standard taxonomic procedures
and by publishing their papers in pharmaceutical journals not read by botanists.
The pharmacognosists did not consult the most recent botanical works, notably
those of Hieronymus (1895) and Schulz (1907a, b) published in Germany. If they
had, much of the confusion would not have occurred. There was no concept of
voucher specimens among chemists and pharmacists, which made it difficult for
subsequent workers to know which species or variety was originally studied. The
few authentic herbarium specimens of coca existing at this time were preserved in
European herbaria and remained largely unavailable to workers in America and
other parts of the world.
By the turn of the century, the literature on the botany and medicinal uses of
coca had become extensive and in some cases hopelessly confused. After decades of
study, there was still no consensus among interested scientists about the botanical
identity of the commercial varieties. This taxonomic confusion directly affected the
thriving commerce in coca leaves since different varieties had different chemical
properties and constituents, and were used for different purposes.
It is my purpose here to review the confusing scientific events of this critical
period.
THE EARLY PERIOD

Triana & Planchon (1862) were the first authors to cast doubt on the
monospecific concept of plants cultivated under the name coca. I n their early
Flora of Nueva Granada (present-day Colombia), they assigned Colombian

20.
332 ‘r. PLOWMAN
specimens of coca to Lamarcks Erythroxylum coca. However, they noted distinct
differences among the Colombian material (Linden 2181; Triana s.n. ; Purdie s.n.) :
the lighter green, obovate-oblong leaves, the longer, more slender pedicels and the
widely spaced stipules (lack of ramenta). They also noted one specimen (Goudot
s.n.) which they thought to be intermediate between E . coca and the Colombian
plants. Triana & Planchon raised the question of whether the differences they
observed might be the result of individual variation in E. coca or whether they
might indicate the existence of distinct varieties of coca. They declined to name
any varieties and considered the differences to be too small to indicate a separate
species.
Regel (1869) illustrated and described a coca plant cultivated in Erlangen,
Germany, under the name “Erythroxylum mexicanum H.B.K.” (Fig. 2 ) . He had

Figure 2. The first illustration of Erythroxylum novogranatcnse var. novogranotense, which appeared in
Regel’s Garfenfira (1869) under the name “Erythroxylum mexicanum H.B.K.”.
 COCA 333

received the plant from the firm of Herman Linden of Brussels as E. coca Lam., but
observed that this plant differed from true coca in having narrower leaves which
were attenuate a t the base and solitary flowers born in the leaf axils. True coca, he
stated, had broader leaves and flowers born in fascicles on the old wood. However,
Regel misidentified the plant. Erythroxylum mexicanurn H.B.K. is a wild species from
drier parts of Mexico, which has never been cultivated. Regel’s drawing
represented the first illustration of Colombian coca, E. novogranatense (Morris)
Hieron. var. novogranatense.
I n 1876, a second illustration of E. novogranatense var. novogranatense appeared in
The Garden under the name “E. coca Lam.” (Fig. 3 ) . This plant was cultivated in
the Economic House at the Royal Botanic Gardens, Kew. The same plant was
illustrated, again as “E. coca”, in Bentley & Trimen (1880).The latter illustration
included drawings of coca fruits which were taken from an unspecified herbarium
specimen of Bolivian coca in the Herbarium, Kew. Both of these illustrations figure
prominently in later taxonomic discussions of the identity of coca.
Peyritsch (1878) wrote an account of 82 species of the genus Erythroxylum
thought to occur in Brazilian territory. The only cultivated species mentioned was
Erythroxylum coca. Peyritsch included in this concept both the Andean and
Amazonian varieties of E. coca, following the earlier work on Erythroxylum by von
Martius ( 1843).
Squibb (1885), the pharmacist, mentioned a new commercial coca plant, which
was known as ‘Peruvian coca’ and which was beginning to enter the

Figure 9 . Illustration of the “Kcw Plant”, Eyfhroxylum novogrunuknse var. novogranateme. published
anonymously in The Garden (1876) under the name “ E . coca Lam.”.
334 T. PLOWMAN

pharmaceutical markets. Squibb was concerned with the problems of preservation

of coca leaves on their long journey from South America, since they often arrived
in Europe and North America in very bad condition, lacking all of their original
properties. Squibb distinguished two varieties of commercial coca at this time but
made no attempt to identify them by scientific names. The first variety, ‘Bolivian
coca’, originated in the Yungas of the Bolivian Andes east of La Paz and was
shipped from the ports of Mollendo (southern Peru) and Arica (northernmost
Chile). He described this leaf as larger, broader, more rounded, thicker, stronger
and less easily broken up in shipment. It was a dull, deep olive-green on the upper
side and much lighter green beneath, becoming yellowish brown or brown with
age. Two distinct lines parallel to the midrib were found characteristically on the
underside of the leaf.
The second variety, ‘Peruvian coca’, was shipped from the city of Salaverry, the
port for Trujillo on the north coast of Peru. Squibb described this coca as having a
smaller, narrower, thinner and more fragile leaf which was easily broken during
gathering, drying and packing. It had a much brighter green colour when in best
condition, becoming duller, lighter and more yellowish green with age and during
transport. The characteristic lines on the underside were often more faint and
frequently indistinguishable. This is the first description of what would later
become known as ‘Trujillo coca’.

THE KEW PLANT

The next major event in the taxonomic history of coca centred on a plant,
already illustrated as “E. coca Lam.” (Regel, 1869; Bentley & Trimen, 1880)
which was soon to become known as the “Kew Plant”. The origin and identity of
this plant were discussed in a paper delivered in 1888 by Sir Daniel Morris at the
Linnean Society of London (Morris, 1890), portions of which appeared in Morris
(1889). Morris was then Assistant Director at Kew and former head of the
Department of Gardens and Plantations in Jamaica.
Morris (1889) remarked that the Kew Plant had been in cultivation for more
than 20 years, dating its introduction to the same year (1869) that this species was
received by Regel in Germany. In that year, the plant was also introduced
experimentally at the Botanical Garden at Hytres, France (Mariani, 1888, 1890),
and in the French island of Martinique (Duss, 1897). Morris stated that the Kew
Plant was raised from seed “for which Mr Abraham Dixon, who presented it to
Kew (in 1869), was indirectly indebted to the Bishop of Hudnuco. From this plant there
have been produced some hundreds of plants, which have been distributed to
numerous correspondents in different parts of the world” (italics mine).
It is important to point out that Morris never stated specifically that the seeds of
the Kew Plant originated in Huanuco (Peru), nor that they were sent, at least
directly, by the Bishop of HuPnuco. Nevertheless, Burck (1890), in a recounting of
Morns’ article, misquoted him by stating that the Kew Plant was grown from seeds
“obtained from Huanuco”. J. D. Hooker ( 1894) repeated this misinterpretation in
stating that Dixon raised the Kew Plant from seeds “sent him by the Bishop of
Hu6nuco”.
In fact, we do not know the immediate origin of the seeds of the Kew Plant, but
it seems certain that they did not come from Huanuco where the species does not
occur. We now know that this variety, Erythroxylum novogranatense var.
 COCA 335

novogranatense, is native to Colombia, and the seeds must have originated there
(Schulz, 1907b; Plowman, 1979, 1980a). The oblique statement coupled to the
name of Abraham Dixon may have been a deliberate attempt to mislead
competing horticulturalists from discovering the source of seed of the plant. Given
the sudden appearance of this variety in Germany, England, France and
Martinique in 1869, it seems likely that the seeds came from a common source,
possibly the Belgian firm of H. Linden.
Morris (1889) named the Kew Plant as a new variety of coca, Erythroxylum coca
var. novogranatense. He chose the most appropriate specific epithet because the plant
matched very well specimens collected in Nueva Granada by Triana and Purdie,
specimens upon which Triana & Planchon (1862) had already commented. Morris
also cited specimens collected in cultivation in the British colonies of Jamaica and
St Lucia. He characterized his new variety by its pale green leaves which were
obovate in shape and obtuse or emarginate at the apex. In habit it was more leafy
and more diffusely branched than typical E. coca. He also mentioned that the
leaves preserved their light green colour upon drying.
Chemically, E. coca var. novogranatense yielded, according to Morris, “nearly, if
not quite, as high a percentage total cocaine [as typical E. coca]”, but much of this
was uncrystallizable. Typical E. coca, on the other hand, produced a much greater
percentage of crystallizable cocaine. Furthermore, he considered E. coca var.
novogranatense to be a lowland plant which throve at sea level in the tropics,
“growing in hotter conditions than those suitable to the type”, i.e. E. coca.
Erythroxylum coca var. novogranatense seemed to yield a larger crop of leaves than
typical E. coca but fruited more sparingly (Morris, 1889).
Morris (1889) also mentioned several kinds of coca which he considered to be
intermediate in leaf shape and size between the typical E. coca and his new variety.
One of these was a plant collected by Richard Spruce (no. 73) in 1854 in the Rio
Negro region of Brazil, recently described as a distinct variety, E. coca var. ipadu
Plowman, or “Amazonian coca” (Plowman, 1980b, 1981).
Morris (1889) believed that coca plants from Java, which he received from Dr
Melchior Treub, Director of the Buitenzorg (Bogor) Botanical Gardens,
corresponded exactly to Spruce’s Amazonian coca collection. He provisionally
classified these collections as corresponding to Bolivian coca (E. coca var. coca).
However, a specimen at Kew dated 1894 is labelled “raised from seeds sent from
Java by Dr Treub in 1883”. This collection clearly represents E. novogranatense var.
novogranatense and appears very different from Spruce’s Amazonian plant. It is
possible that Morris did receive seeds of E. coca, also known to have been grown
experimentally in Java at about the same time. This would be more congruent
with Morris’ statement that Java coca leaves contained mostly crystallizable
cocaine, a fact contradicted by later workers. Without authentic specimens
annotated by Morris, it is impossible to clarify this question further. In any case,
there is some doubt that the plant which Morris received from Java was that which
later became known as typical ‘yava coca”.
Following his description of Erythroxylum coca var. novogranatense, Morris ( 1890)
observed that his variety “approached very nearly (although not so coriaceous) as
what are known in commerce as Truxillo [sic] leaves”. It is clear that he was
familiar with the relatively new commercial Trujillo coca, and Morris was the first
botanist to attempt to identify the Trujillo variety in taxonomic terms. In
discussing the cocaine content of coca leaves received from India, Morris noted
336 T. PLOWMAN

their similarity to Trujillo coca in their high content of uncrystallizable cocaine

(Morris, 1889).
Morris (1889) concluded with a discussion of the commercial value of coca
leaves. He quoted Messrs Burgoyne in the U.S.A. that the stock of coca leaves in
New York City in 1888 consisted of 10000 lb of Huanuco (Bolivian) leaves and
40 000 lb of Trujillo leaves. The Huinuco leaves were used for extracting cocaine,
whereas the Trujillo leaves were employed only in pharmacy and for preparing
coca wine. His correspondents further remarked that the Trujillo leaves were as
strong as the Huinuco leaves in alkaloids, but their product would not crystallize,
an observation consistent with later chemical studies on coca.
This is one of the earliest mentions of ‘Huanuco coca’ as a synonym of ‘Bolivian
coca’, a fact which is clear today but was a matter of some confusion in the late
1800’s. The common names were a constant source of misunderstanding because
‘Huanuco coca’, named for a city and department in central Peru where they
originated, could easily be mistaken in name for ‘Peruvian coca’, a synonym of
‘Trujillo coca’ which originated from the dry, north coast of Peru at the city of
Trujillo. The other main South American variety, ‘Bolivian coca’, orginated
farther south in the Bolivian Yungas.
Although Morris ( 1889) correctly identified and characterized Colombian coca
as distinct from typical Erythrovlurn coca, numerous questions remained
unanswered, especially regarding the various kinds of coca received in commerce
from South America and those being cultivated in the European colonies.

JAVA COCA

The first coca plants grown in Java were introduced at the Bogor Botanical
Gardens in 1875. Two living plants were sent to Bogor from Belgium by the same
H. Linden Go. (Burck, 1888, 1890), which had earlier supplied seeds to Regel in
1869. It seems likely that the plants sent to Java were progeny of Linden’s original
stock of E. novogranatense var. novogranatense, a variety known to be self-compatible
(Ganders, 1979) and to fruit abundantly in cultivation.
In 1885 and 1886, experimental plantings of coca were made at the agricultural
garden at Tjikeumeuh near Bogor, from seed produced by the two mother plants.
In February of 1886, 4000 seedlings were set out in a former coffee plantation. By
1888, by order of the Government, large quantities of seed were being distributed
to applicants in all parts of the Dutch East Indies (Burck, 1887, 1890; Treub,
1890).
A year after Morris’ first paper appeared, William Burck, Assistant Director in
charge of the herbarium at the Bogor Botanical Gardens, published an account in
Dutch (Burck, 1890) of the history and identity of the cultivated cocas, with special
reference to plants being grown in Java. His interest was spurred by the fact that
Java coca produced far greater amounts of alkaloids (up to 2.21°4, total alkaloid)
than previously had been reported for Bolivian coca (up to 0.55O/;, total alkaloid).
Burck had access to Morris’ paper which he quoted freely but erroneously
attributed to Dr Thiselton Dyer, then Director at Kew (Burck, 1890). Parts of
Burck’s paper were translated into English and published in 1892.
Burck (1890) recognized two kinds of coca being cultivated in Java: ‘Java coca’,
the origin of which is described above, and ‘Bolivian coca’, which was not often
cultivated and little known in Java. After reviewing the sparse literature on coca
 COCA 337

which was available to him, Burck decided that neither of the varieties grown in
Java belonged to any previously described species or variety. Burck’s studies
suffered from a lack of original literature and comparative herbarium specimens,
as well as unavailability of types and authentic material of E. coca Lam. His
concept of this species was drawn from Morris’ fig. 1, an illustration redrawn from
the plate originally prepared by W. J. Hooker (1836). In redrawing the plate,
Morris (or his artist) changed the shape of the leaves. Since none of the cultivated
cocas known to him fitted this drawing, Burck concluded that Lamarck’s E. coca
was a rare plant from Peru with oval, pointed leaves and was not the common coca
of commerce.
Burck (1890) next discussed Morris’ new variety E . coca var. novogranatense. He
had not received any authentic material of the original “Kew Plant”, so he relied
heavily in his interpretation on the drawing published in The Garden in 1876 and
reprinted in Morris’ article. However, it is very likely that commercial Java coca,
originating as it did with Herman Linden Co., had a common parentage with the
plants received by Regel (1869) and possibly with the Kew Plant itself.
Burck (1890) proceeded to describe the two cultivated cocas which he
considered new to science, beginning with the commonly cultivated ‘gava coca
plant”. He named this variety Erythroxylurn coca var. spruceanurn based solely on
Morris’ statement that specimens of Java coca plants at Kew matched Spruce’s
coca collection from the Rio Negro. Burck did not see Spruce’s original unicate
specimen at Kew, but, following Morris, stated that Java coca was intermediate
between true E. coca and Morris’ var. novogranatense.
Burck considered his new variety E . coca var. spruceanurn to be equivalent in rank
to Morris’ E. coca var. novogranatense. Erythroxylurn coca var. spruceanurn differed, he
wrote, by its greater stature, its characteristically bushy habit, and by the shape,
tip and colour of the leaves. He described the Java coca leaf as ovate, acute and
mucronate at the tip, attenuate at the base, with a flat upper midrib, thin, and
light green above and pale beneath. It produced one to five white flowers per node
and contained a high percentage of alkaloids in the young leaves, which
diminished with age. Burck furnished an excellent illustration of the habit and
branch of Java coca (Fig. 4).A lectotype specimen (Burck 9) is preserved at the
Herbarium Bogoriense to confirm the identity of Java coca as E. novogranatense var.
novogranatense.
The second coca cultivated at the Bogor Botanical Gardens, albeit on a small
scale, originated from seed sent in 1889 from the firm of Thomas Christy, London,
and from the director of the Calcutta Botanical Garden. Burck believed that this
plant, which he described as a new species, Erythroxylurn bolivianum, represented the
Bolivian coca of commerce but that it did not match Lamarck’s concept of E. coca.
Apart from the shape and apex of the leaves, Burck provided no substantial
characters with which to differentiate his new species from typical E . coca, his
concept of which was based entirely on the misdrawn figure of Morris.
Burck characterized E. bolivianum as a small plant up to 3 ft tall, hardly
branched, with broadly elliptic, obtuse or rounded, mucronate leaves which were
obtuse at the base and markedly ridged at the midrib above. It had coriaceous
leaves which were green above and lighter green beneath and bore five to ten
flowers per node. He noted the flowers were yellowish green with a pure white
<<
corona”. In contrast to E. coca var. spruceanurn, E. bolivianum produced a maximum
of only 0.55”,, alkaloids in the dried leaves. He furnished a good illustration of the
 T. PLOWMAN

Figure 4. Burck’s (1890) illustration ofJava coca, first described as Erythroxylwn coca var. gruceaswn and
now considered to be E. novogranatcnst var. novogranatense.
 COCA 339

Figure 5. Burck’s (1890) illustration of E@hroxylum bolivianum, now considered to be E. cocu var. cocu.
340 T. PLOWMAN
habit and a branch of the plant (Fig. 5), which clearly indicates that E. boliuianum
Burck is a synonym of E. coca Lam. A representative specimen, collected at the
Bogor Botanical Garden in 1906 and labelled “E. bolivianum”, is preserved at the
Botanical Museum, Utrecht.
Although Burck was a careful observer and made accurate descriptions based on
living plants of the cultivated cocas, he merely renamed the two species of coca
already commonly cultivated in other parts of the world, namely E. coca (var. coca)
and E. novogranatense (var. novogranatense) . His introduction of superfluous names into
the literature, based on coca plants cultivated in the East Indies, created new
nomenclatural confusion in Europe and North America in the years to follow.
Holmes (1892) wrote a paper on the commercial varieties of coca for the
Pharmaceutical Journal, which had become the principal forum for the scientific
discussion of the properties of coca and cocaine. Holmes asserted that there were
two main varieties of coca found in the British market : the Trujillo or Peruvian leaf
on the one hand, and the Bolivian or H u h u c o leaf on the other. He also
mentioned the occasional appearance of Java coca leaf in British commerce.
J. D. Hooker (1894) attempted to clarify the confused nomenclature of the
cultivated cocas. He pointed out the difficulties in naming cultivated plants: “As is
to be expected in the case of a plant cultivated over so great an area, it has given
origin to different local forms, amongst which none can be regarded scientifically
as the type, owing to the fact that the native country of the species has not yet been
satisfactorily ascertained”. He cited the need to give priority to the original
description of the species Erythroxylwn coca of Lamarck. True E. coca, he wrote, is
distinguished by rather large leaves with an acute or rounded apiculate apex.
Hooker furnished a good colour plate of E. coca, drawn from a plant received at
Kew in 1884 from the botanical garden at Demarara (Guyana), which flowered at
Kew in April 1893. A herbarium specimen of this plant is preserved in the Kew
Herbarium, verifying its identity as E. coca.
Hooker also mentioned what he believed to be the two varieties of E. coca then in
cultivation at Kew. The first of these was the Kew Plant, which he considered to be
a form cultivated in Colombia with smaller, retuse-apiculate leaves. The second
was Burck’s E. coca var. spruceanum, which had been introduced in cultivation at
Kew from seeds sent from Bogor. Hooker distinguished Java coca by the acute
leaves which were much smaller than typical E. coca and of a very bright green
colour.
Hieronymus (1895), then working in Berlin, elevated E. coca var. novogranatense of
Morris to the rank of species, after studying the coca specimens collected in
Colombia by F. C. Lehmann. Hieronymus cited E. cataractarum Spruce ex Peyr. -
not E. coca - as the closest relative of E. novogranatense, suggesting for the first time
that the two cultivated cocas may have had quite different origins among the wild
cocas of South America. Hieronymus placed the wild species E. panamense Turcz. in
synonymy with E. novogranatense, but this species is now known to be very different
(Schulz, 1907b).
Hieronymus (1895) distinguished E. novogranatense from E. coca on the basis of its
narrower leaves, obtuse or sub-obtuse apex and the less prominent venation.
Although Hieronymus was first to correctly identify Colombian coca as a distinct
species, his paper never became known to the community of pharmacognosists in
Europe and North America, among whom the botany of coca was most disputed.
About the turn of the century, studies on the botany of coca began to shift to
 COCA 34 1

the U.S.A. Schneider (1898), a student of H. H. Rusby, conducted

morphological and anatomical studies on the commercial varieties of coca found in
the U.S.A. Like Holmes in England, he recognized two main kinds of commercial
coca : Trujillo coca and Bolivian coca. Following Burck, Schneider maintained
that E. coca was a rare species and was not introduced into Java, India, Jamaica,
Trinidad or Australia. He believed that E . coca var. novogranatense was extensively
cultivated in South America and in British India but stated that all attempts to
introduce it into Java had been unsuccessful. Anticipating Rusby’s work of 1900,
Schneider stated that E. coca var. spruceanum should be given specific rank and that
Burck’s E. bolivianum was nothing more than “the basest kind of a synonym for E .
coca Lam.”.
Anatomically, Schneider (1898) could find few good characters to separate the
two kinds of coca, especially when they were pulverized in pharmaceutical
preparations. However, he did observe that Trujillo coca showed more prominent
papillae on the lower epidermis and a well-developed second layer of palisade cells.
Schneider appended to his paper a note on the Brazilian form of coca known as
$adti (probably E . coca var. ipadu). He described this leaf as larger, slightly tougher
and fully as thin as that of Peruvian (Trujillo) coca, but with somewhat less
prominent veins. The upper epidermal, palisade and spongy tissues, he said, were
like Bolivian leaves but the lower epidermis had characteristically prominent,
globose papillae by which Brazilian coca could be readily be distinguished from all
other types. The diagnostic value of the epidermal papillae has been questioned in
a recent review of the anatomical features of the cultivated cocas (Rury, 1981).

THE RUSBY ERA

Henry Hurd Rusby began his studies on coca in 1885, when he was sent to South
America by the Parke Davis Company to secure adequate supplies of the best
Bolivian coca (Rusby, 1933; Lipp, 1974).As a result of his two-year sojourn during
1885-1886, he published one article on the cultivation of coca (Rusby, 1886) and
another on the role of coca in Andean life (Rusby, 1888).He also described six new
wild species of Erythroxylum, five of which are today considered valid species.
Trained mainly as a physician and pharmacist, Rusby’s botanical studies
suffered from a lack of formal education in taxonomy. But his enthusiasm for
botany and exploration more than compensated for his academic deficiencies and
he wrote prolifically. His extensive plant collections in Bolivia in 1885-1886 and
during the Mulford Biological Expedition in 1921-1922 are his greatest
contributions to botanical science. These collections not only include many species
new to science but also represent even today the only records ofplant life in parts of
Bolivia.
In his most important paper on coca, Rusby (1900) unequivocally stated that
Erythroxylum coca Lam. was the source of Bolivian, Huanuco, Brazilian, and most
Venezuelan and Argentinian coca. He pointed out, correctly, that E. bolivianum
Burck was a synonym of E. coca and could not stand as an accepted name. H e
believed that the best illustration ofE. coca was that of Cavanilles (1 789) which had
been overlooked by previous workers, notably Morris. Instead, Morris had
referred to Hooker’s illustration (1836) which Rusby considered to bear “no
resemblance to it”. A comparison of Hooker’s original and Morris’ copy of the
342 T. PLOWMAN

drawing makes it appear that Rusby knew only the inaccurately drawn copy of‘
Morris, rather than Hooker’s original illustration which is completely accurate.
Rusby’s avowed method of determining the ancestral form of a cultivated plant
was to study it in its “reverted state of wildness”, and he applied this idea to coca
during his first Bolivian expedition. He believed that he had found wild-growing
E. coca in a ravine near Coroico in the Bolivian Yungas, which differed
morphologically from cultivated coca as a result of its reversion to the wild. For
example, he believed that wild-growing coca produced thicker leaves with stronger
veins; the leaves were darker and shinier above and brown and roughened
beneath, and lacked the lateral lines of typical cultivated coca. By comparing his
descriptions, notes, drawings and herbarium collections (deposited at the New
York Botanical Garden, University of Michigan herbarium and elsewhere), we
now know that Rusby’s “wild-growing coca” referred not to E . coca as he himself
believed but to several wild species of Erythroxylum. These species occur naturally in
the Yungas area and superficially resemble cultivated coca. Although Rushy
rarely cited collection numbers, it has been possible to match his published
descriptions and figures (Rusby, 1900) with numbered herbarium specimens in
many cases.
The first of Rusby’s “wild cocas”, all of which he assigned to the species E. coca,
was illustrated in his fig. 4 and corresponds to the common Andean species E. ulei
0. E. Schulz. Rusby labelled this collection (Ruby 2078) as “E. coca Lam.,
Bolivian form, escaped for centuries”, and described it as “wild, sun-grown coca
leaf’ (e sched.) and “coca reverted to the wild state (Rusby 1900). In his fig. 5,
he illustrated a second “wild, sun-grown coca” based on a collection made at
Mapiri (Ruby 2080). Rusby designated this collection, and another (Rusby 2082)
which matches it, as “wild, history unknown”. These plants have a distinctive
ovate-acuminate leaf, which he considered to be another tendency of E . coca
“reverted to the wild state”. Both of these collections suggest juvenile forms of
E. anguifgum Mart., a wide-ranging species of Brazil, Paraguay and Bolivia.
Rusby found a third wild coca in Amazonian Bolivia in 1886 (Rusby 2076). He
pencilled a note on a duplicate specimen at the University of Michigan which
reads “E. coca, the Peruvian form, growing in deep forest shade. Escaped from
Cuzco, Peru, to the junction of the Rivers Beni and Madre de Dios via the Madre
de Dios River”. This collection, like most of his “wild coca” collections, is sterile
but appears to be E. gracilipes Peyr. Rusby (1900) misidentified this plant as E.
popuyanense H.B.K. (which he incorrectly wrote as “E. fipuyannensis Poepp.”) and
illustrated it in his fig. 7. Evthroxylum popuyaneme is a rare plant from Colombia
which has not been found since the early collections of Humboldt and Bonpland.
Rusby also included in his misguided concept of E. popuyanense a plant which he
found on the lower Orinoco River in Venezuela (Ruby &’ Squires 267) and
illustrated in his fig. 9. He believed this coca matched the “forest form” of the plant
from the Rio Beni (Rusby 2076) and represented a “very ancient cultivation of this
plant at the mouth of the Orinoco” (Rusby, 1896). The Orinoco collection closely
resembles E. recurrens Huber, an Amazonian species with close affinities to E.
gracilipes.
Having discussed the question of wild versus cultivated E. coca, Rusby (1900)
turned to the varieties of commercially cultivated coca. He described the
commercial Bolivian leaf as “typically oval, varying to obovate, and acutish to
acute at both ends, often slightly mucronate”. “The Huanuco Peruvian leaf’, he
 COCA 343

said, “was similar but one half larger”. For the first time, he clarified the slight
difference between Bolivian and Huinuco coca which, besides the area of origin,
differ mainly in their relative sizes. He correctly referred to Burck’s illustration of
E. bolivianurn as a typical example of E. coca (Fig. 5).
Among those which he considered to be commercial varieties, Rusby described a
number of kinds of coca and their places of origin. Since these now appear to be
wild species, or at least of minor or local importance, it is possible they were
received as adulterants. For example, Rusby mentioned a wild coca from Jujuy in
northwestern Argentina, locally known as ‘tC’ (‘tea’) and illustrated in his fig. 13.
This leaf, he stated, was similar to “very poor quality neglected or wild Bolivian
leaves, except in shape”. He described it as lacking the taste and benumbing effect
of typical coca and doubted that it belonged to E. coca. From the description and
locality, this coca most likely belongs to the wild species E. argentinurn 0.E. Schulz,
described in 1907.
Rusby (1900) next turned his attention to Trujillo coca, which at that time had
become an important pharmaceutical item in United States commerce. Rusby
maintained that the Trujillo leaf available in North America differed from the
coca described and illustrated under that name in British journals. H e
characterized Trujillo coca, or the “small green leaf which was received directly
from Peru”, as follows: “[It] is mostly from 3 x 1$ to 4 x 1+ cm. It is obovate, with
narrowed base, mostly acute or acutish at the apex and minutely apiculate. I n
commercial leaves, the lateral lines are commonly faint or even wanting. . . . The
leaf is very pale, dull, thin and fragile, and is usually easily broken” (Rusby, 1900).
At about the same time that he was working on the identification of the varieties
of coca, Rusby discovered, apparently inadvertently, a plant in cultivation at the
conservatory of the New York Botanical Garden. He knew nothing of the origin of
this plant but likened it to what he believed to be Trujillo coca, although not
without some reservations. He provided a brief description of the plant and stated
that it was “unquestionably the same thing which Dr. Burck speaks of asJava coca
and for which he proposes the name E. Coca Spruceanurn [sic]” (Rusby, 1900).
The living specimen which Rusby discovered may have been one of the plants
which coca wine entrepreneur Angelo Mariani sent from Paris to W. G. Mortimer
in New York. Mortimer received ten coca plants from Mariani in September 1898,
and presented them to the New York Botanical Garden. These plants were still
alive in 1900 because Mortimer wrote that they had doubled in size in the
intervening two years and furnished a photograph of the plants (Mortimer, 1901).
Rusby made a herbarium specimen of the living plant in flower in August 1900,
and deposited it in the New York Botanical Garden herbarium. The following year
he provided further descriptive details of the plant and published a line drawing of
it (Rusby, 1901 : fig. 2). From both the specimen and from Rusby’s illustration, it is
clear that this plant is E. novogranatense var. novogranatense.
Rusby confused the commercial Trujillo coca with the living plant at New York,
which he identified “positively” as Burck’s E. coca var. spruceanurn. However, he
then stated that this name was “impossible” because of the existence of the earlier
name E. spruceanurn Peyr. for a wild tree of the Rio Negro, Brazil (Peyritsch, 1878).
Rusby implied that Burck’s var. spruceanurn was a later homonym, which it is not
because Burck used the epithet at the varietal rank, Peyritsch at the specific rank.
O n this basis, Rusby concluded that commercial Trujillo coca needed a new
scientific name, for which he proposed E. truxillense (Rusby, 1900).
344 T. PLOWMAN
Deviating from standard botanical practice, Rusby (1900) did not give a proper
description of his new species nor a Latin diagnosis; nor did he cite a type
specimen. Ttie specimen in cultivation at New York, although labelled E.
truxillense in his own handwriting, must be excluded as the type of E . truxillense
because it was misconstrued by Rusby as being identical with the Trujillo leaves of
commerce.
Since it was Rusby’s intention to describe and name the Trujillo leaf found in
the New York pharmaceutical trade, a specimen of this material should be
designated as a lectotype for the species. An appropriate specimen was discovered
in 1979 among Rusby’s vast materia medica collection now housed at the Harvard
Botanical Museum. A jar of coca leaves in this collection is labelled “No. 2684,
Erythroxylum truxillense Rusby, Truxillo coca, small coca, native of Peru and
cultivated. The commercial drug presented by E. Merck & Co., New York City”.
This specimen has been designated as the lectotype of E. truxillense (Plowman,
1980b). The provenience of this specimen is confirmed by the occasional presence
in the sample of leaves of the leguminous tree Inga feuillei DC. This tree, a native of
Peru, is commonly planted as a shade tree in plantations of Trujillo coca, and its
leaves often appear as a contaminant of commercial Trujillo leaf (Plowman,
1980b).
Rusby (1900) summarized the differences between E. truxillense and E. coca and
hesitantly stated: “I have concluded that they must be [distinct], and I assign the
name E. Truxillense to the one under consideration. Even if it were regarded as a
variety of E. Coca only, it must bear the name var. Truxillense, as Burck’s name is
preoccupied under accepted rules”. Rusby compared his new species to other,
previously described South American species of Erythroxylum, but could find “no
specific description which is applicable to it, unless it be that of E. hondense H.B.K.
of which there is no figure” (Rusby, 1900). The description ofE. hondense, he said,
agreed well with his Trujillo coca except for the lateral lines which are absent in
E. hondense and often present in commercial Trujillo coca.
Finally Rusby (1900) discussed the position of Morris’ E. coca var. novogranatense,
which he consistently and erroneously wrote “var. Neo-granatense”. He
acknowledged that this was the plant widely cultivated in the British colonies of
the East and West Indies, descended from the original Kew Plant, and observed
correctly that the leaves of this variety did not reach the U.S.A. in commerce.
Chemically, he contended, E . coca var. novogranatense was closer to Trujillo than to
Bolivian coca but morphologically was entirely different from both. Rusby did
admit to being quite unfamiliar with Morris’ var. novogranatense “except through
the living plants at Kew”. Why he failed to recognize the close similarity between
the living Kew Plant and the living plant he described at the New York Botanical
Garden will never be known.
Relying solely on the details of the figure published by Morris, Rusby (1900)
enumerated the differences between E. coca var. novogranatense and other cultivated
cocas ; in this comparison, he restricted himself to floral characters taken from the
illustration. These differences, he maintained, were so great that Morris’ var.
novogranatense must be a distinct species. He was unaware that five years earlier
Hieronymus had published E . novogranatense as a valid species (Hieronymus, 1895).
Rusby searched the botanical literature for Erythroxylum species known from
Colombia and found one which he insisted conformed to this plant, namely E .
carthagenense Jacq., and thereby made one of his greatest errors in plant
 COC.4 345

identification. Referring to the crudely drawn figure of E. carthagenense published

by Jacquin (1763), Rusby was convinced that it matched Morris’ var.
novogranatense. O n the basis of modern collections, it is known that E. carthagenense is
in fact a valid species, but is completely distinct from E. novogranatense. It is a stiff-
branched, maritime shrub restricted to the dry Caribbean coast of Colombia. The
leaves are not employed for chewing, and recent analyses show that they contain
no cocaine (Holmstedt et al., 1977).
Rusby (1900) concluded with what he believed should be the “definition of
coca”: “the leaves of Erythroxylum coca Lam., E. truxillense Rusby and E.
carthagenense Jacq.”. In spite of his numerous errors and inconsistencies, this
account was the most complete review to date of the taxonomy of the cultivated
cocas. More importantly, it was the first valid scientific description and naming,
however incomplete, of Trujillo coca. His epithet ‘truxillense’ now serves as the
basionym for the valid name for Trujillo coca, E. novogranatense var. truxillense
(Rusby) Plowman (Plowman, 1980a, b) .
Three months later, Holmes (1901) reviewed Rusby’s paper and clarified or
criticized several points. For example, Holmes pointed out Morris’ error in
copying W. J. Hooker’s (1836) illustration of E. coca. He also announced that
Rusby’s copy of Cavanilles’ illustration of E. coca was also inaccurate, that the fruits
were drawn oblong and obtuse instead of distinctly ovoid and acute as in the
original. Holmes published an illustration of Java coca which he erroneously cited
as “E. Spruceanum Burck”. His drawing was prepared from a herbarium specimen
of a plant cultivated in Java. Holmes considered this plant to match Rusby’s
description of the live plant at the New York Botanical Garden. The only
difference, he said, was the colour of the flowers. Holmes discussed Morris’ E. coca
var. novogranatense but was uncertain whether or not this variety should be placed in
synonymy with E. carthagenense, as suggested by Rusby. He recommended
maintaining Morris’ ‘species’ until a more precise identification of Jacquin’s
E. carthagenense could be made. Holmes remarked : “It is singular that in commerce
the leaves of the type of E. novogranatense are not met with from New Granada, but
only the two types of Huanuco and Trujillo”. (The reason is that E. novogranatense
has never been cultivated on a commercial scale in Colombia.)
In March 1901, Rusby wrote a rebuttal to Holmes’ article defending himselfon
several points. He admitted the error in redrawing the plate of Cavanilles, but laid
the blame on his artist who attempted to improve her copy of the illustration by
supplying characters observed in a greenhouse plant labelled E. coca, but which
Rusby identified as E. truxillense. He further tried to vindicate himself by suggesting
that by drawing the obovate fruits of E. truxillense on the illustration of E. coca, he
emphasized the importance of this feature as a specific character. This argument
led Rusby to one of his most preposterous statements: “One of the surest evidences
of specific distinctiveness, as opposed to mere variation, is the carrying of a peculiar
leaf-form into the form of the fruit. The most prominent characteristic of
E. truxillense is the relative broadening of its leaf toward the summit, and we see the
same character fixed in the carpellary leaf, giving us an obovoid fruit” (Rusby,
1900).
Some years later, Holmes (1910) issued a final note on the identity of coca in
which he accepted only two species of cultivated coca from South America : E. coca
Sor the Bolivian leaf and E. truxillense for the Peruvian one. Rusby made no
response to this paper and, on the subject of coca, published only a general account
346 T. PLOWMAN

of Huanuco and Trujillo coca for the National Standard Dispensatoy (Hare, Caspari
& Rusby, 1909).
A landmark in Jin de si2cle coca studies was the voluminous compendium History
of Coca published by Mortimer (1901), a New York physician. His well
documented book attempted to summarize everything known to date about the
history, botany and medicinal properties of coca. Mortimer generally referred to
coca as belonging to the species E . coca Lam., but did not make a clear distinction
between species and varieties. Mortimer accepted E. coca var. novogranatense as the
scientific name for Trujillo coca, although Morris (1889) had only suggested that
Trujillo coca might belong to this variety. Although Mortirner knew Rusby and
quoted freely from his work, there is no mention of Rusby’s 1900 paper which
apparently appeared too late to be included in History of Coca. Mortimer
interpreted Burck’s E . coca var. spruceanum as the coca grown on the Rio Negro,
rather than as Java coca as Burck intended (Mortimer, 1901).
In the early 19OO’s, two papers on the anatomy of coca furnished new details on
the microscopic identification of Trujillo and Bolivian coca (Hartwich, 1903;
Greenish, 1904). Hartwich’s careful study laid the foundation for future work on
Erythroxylum leaf anatomy with pharmacognostic applications. Greenish ( 1904)
summarized Hartwich’s paper but considered a different set of anatomical
characters which he considered diagnostic for distinguishing the commercial cocas.

CONTRIBUTIONS OF 0. E. SCHULZ

While pharmacognosists and botanists in England and America continued to

debate the identity of the cultivated cocas, Schulz (1907a, b) in Germany began
publishing detailed monographic studies on the genus Erythroxylum, based on the
large herbarium collections at the Berlin Botanical Garden. His first major work
was a revision of the species of the genus occurring in the Antilles and included
keys and descriptions of 22 species (Schulz, 1907a). The same year he published
the most important work on Erythroxylaceae to date, a world-wide monograph of
the family for Engler’s Pflanzenreich (Schulz, 1907b). Schulz included 196 species
of Erythroxylum in his treatment, of which 50 were described as new to science.
Although his main botanical interests lay in the Cruciferae (Loesener, 1936),
Schulz continued to describe new species of Erythroxylum for the next 30 years.
Schulz (1907b) recognized two species of cultivated cocas: E. coca Lam. and E .
novogranatense (Morris) Hieron., and this classification, with some refinements, is
largely followed today. Schulz provided illustrations of both E. coca (Schulz,
1907b: fig. 17) and E. novogranatense (Schulz, 1907b : fig. 18),which clearly showed
the pertinent differences between them. In his key he separated these species on the
basis of the leaf apex,,the stipule length and the degree of ramenta development.
In his concept of E. coca, Schulz recognized the ‘classical’ coca of Peru and
Bolivia. He also included here specimens of Amazonian coca, now considered
E. coca var. ipadu (Plowman, 1980b). He placed Burck‘s E. bolivianum in synonymy
and cited a few cultivated specimens from Java, but Schulz recognized no formal
varieties within E. coca.
Schulz (1907b) considered E. novogranatense to be a Colombian species, and cited
a series of authentic specimens collected in Colombia, unlike many of his
predecessors. He cited E. coca var. novogranatense Morris as the basionym for E .
novogranatense and placed E . coca var. spruceanurn Burck in synonymy with it.
 COCA 34 7

Although he did not refer to the paper by Burck (1890), Schulz did cite specimens
collected at Bogor Botanical Gardens. Schulz also placed E. truxillense Rusby in
synonymy under E. novogranatense and cited the paper by Rusby (1900). However,
he certainly had seen no herbarium specimens of Trujillo coca at this time and
apparently based his decisions on Rusby’s descriptions and illustrations.
Schulz (1907a,b) recognized three new varieties of E. novogranatense. E .
novogranatense var. tobagense was described from a single specimen collected in
Tobago by Eggers (no. 5832), who noted on the label “spontaneous, also
cultivated” (Schulz, 1907a). This plant appears to be a depauperate form of E.
novogranatense var. novogranatense with particularly small, emarginate leaves. It
resembles specimens collected under cultivation in Trinidad (cf. Hart 5830).The
plant has not been recollected in Tobago and, until studied further, should be
considered a minor variant.
Schulz (1907b) described E . novogranatense var. microphyllum from a form
cultivated in southeastern Brazil at Rio de Janeiro (Glatiou 28260). It is
distinguished by having very small leaves and smaller flowers but otherwise
conforms to typical E. novogranatense var. novogranatense under which it must be
placed in synonymy. Schulz’ third variety, E. novogranatense var. macrophyllum, is a
wild plant collected by Spruce (no. 3725) on the Orinoco River in Venezuela
(Schulz, 1907b). It is known from a single sterile collection of which a duplicate
survives at Kew. It does not belong to E . novogranatense and seems best placed near
E . recurrens, the species which Rusby also collected on the Orinoco.
Unfortunately, Schulz’ excellent work was not known to Rusby or Holmes who
continued to use the older names for the commercial varieties of coca. Their
outdated concepts continue to prevail in the pharmacognostic literature. As
recently as 1977, a leading textbook of pharmacognosy (Tyler, Brady & Robbers,
1977) listed three varieties of commercial coca, all as varieties of Erythroxylum coca
Lam.: 1, E. coca var. coca, Huinuco or Bolivian coca; 2, E. coca var. spruceanurn
Burck (including E . truxillense Rusby in synonymy), Trujillo or Java coca; and 3,
E. coca var. novogranatense Morris, which, it is said, yields a “type of Trujillo coca
from Colombia”.
From the late 1880’s to the early 19OO’s, cocaine increased steadily in popularity,
first as a medicine prescribed by physicians and subsequently as a freely available
recreational drug. This same period saw a gradual decrease in the use of coca
leaves and coca leaf extracts, as the pure alkaloid cocaine, thought by some to be
identical in effect to coca leaf, gradually replaced the natural product. The
proliferating use of cocaine as a recreational drug was accompanied by
concomitant condemnation by segments of the medical establishment and the
general public. This led to the passage of a series of laws by the U.S. Congress
aimed at restricting the availability of cocaine as well as coca leaves. In 1922, the
U.S. Congress prohibited most importation of coca leaves, except in small amounts
necessary to manufacture cocaine for legitimate medical purposes and for
flavouring beverages like Coca Cola. Similar restrictions were also imposed in most
European countries (Ashley, 1975; Grinspoon & Bakalar, 1976).
As a result of its replacement by cocaine in medicine and subsequent laws
restricting its use, coca became unavailable to physicians and pharmacists alike.
Pharmacognosists were only rarely confronted with problems of the identification
of coca, although production of coca leaves for cocaine extraction was prodigious
in the early 1900’s. Except for a few isolated studies ofJava coca (Reens, 1919a, b)
348 T. PLOWMAN

and on the systematic leaf anatomy of Erythroxylum species (Ballard, 1926),

botanical studies on coca essentially ceased around 1910, shortly after the
publication of Schulz’ monograph, and were not resumed until the 1950’s.

CONCLUSION

Now, after almost 200 years since coca was first scientifically described, it is
possible to make an intelligent assessment of the taxonomic status of coca. This has
been made possible through intensive field studies in South America, extensive
surveys of the chemical, botanical, pharmaceutical and anthropological literature,
and through careful study of specimens from South America and other tropical
regions preserved in the world’s herbaria. In addition, cytological, phytochemical,
anatomical and breeding system studies have greatly contributed to our
understanding of the biosystematics of the cultivated cocas (Ganders, 1979;
Rury, 1981; Bohm, Ganders & Plowman, in press). With this background, it is
finally possible to evaluate the complex events in the taxonomic and
nomenclatural history of coca which contributed eventually to the correct
identification of the plants involved.
As now understood, the cultivated coca plants belong to two distinct species,
Erythroxylum coca Lam. and E. novogranatense (Morris) Hieron., as originally defined
by Hieronymus (1895) and Schulz (1907b) and further elucidated by subsequent
authors (Payens, 1958; Gentner, 1972; Machado, 1972; Plowman, 1979, 1980a).
Within the genus Erythroxylum, these two cultivated species are more closely related
to each other than to any of the numerous wild species. Each of the cultivated
cocas has one distinct variety, E. coca var. ipadu Plowman and E . novogranatense var.
truxillense (Rusby) Plowman, respectively (Plowman, 1980a, b). All four of the
cultivated cocas were domesticated in South America in pre-Columbian times and
continue to be employed today as masticatories by diverse tribes in either the
Andes or Amazon regions.
Erythroxylurn coca var. coca, known as Bolivian or HuPnuco coca, is the most
important commercial species and is still widely cultivated in the Andean region
for legal and illegal production of cocaine. The leaves of E. coca var. coca are
chewed daily by millions of Andean Indians for their stimulant and medicinal
properties. Based on morphological, chemical, ecological and reproductive studies,
E. coca var. coca is considered the most primitive among the cultivated cocas and
appears to be ancestral to the other three cultivated varieties. Wild or feral
populations of E. coca var. coca are found throughout the tropical montaiia of the
eastern Andes both in and remote from areas of cultivation. In contrast, the other
three cultivated varieties are known only as cultivated plants and possibly arose
through human selection in cultivation. However, E. coca var. coca is not easily
cultivated outside its original habitat and remains little known in other parts of the
world. It is rarely found in botanical gardens and conservatories (Plowman, 1979,
1980a, 1981).
Amazonian coca, or Erythroxylum coca var. ipadu Plowman (Plowman, 1980b) is
confined to the lowland rainforests of the Amazon basin. Known generally as
‘ipadu’, the native Brazilian name, this variety is cultivated by a number of
Indian tribes in Brazil, Peru and Colombia, who prepare the leaves by an
elaborate process as a finely divided powder (Plowman, 1981). Amazonian coca is
unknown outside the Amazon valley, where it has always been employed in the
 Table 1. Chronological summary o f taxonomic placements of the cultivated cocas (Erythroxylum spp.)

Authority E. coca var. coca E. coca var. ipadu E. nowgranatmse var. nowgranatense E. novogranatense var. truxillense
~~~

N, - ~

Lamarck, 1786 E. coca Lam.

~ -
\Villdenow. I799 E. coca Lam. E. coca Lam.
~ -
1%‘.J . Hooker, 1836 E. coca Lam. -
~ -
Martius, 18-23 E. coca Lam. E. coca Lam.
- ~

Triana 8; Planchon, 1862 - E. coca Lam.

~ ~

Regel, 1869 E. coca Lam. E. rnexicanum H.B.K

~ ~ -
.4nonymous, 1876 E. coca Lam.
Peyritsch, 1878 E. coca Lam. E. coca Lam. -
~ ~ -
Bentley & Trimen, 1880 E. coca Lam
Squibb, 1885 Bolivian coca Peruvian coca
Morris, 1889 E. coca Lam. E. coca var. nouogranatense Morris E. coca aff. var. nonogranatense
Morns
Burck. 1890 E. coca Lam. E. coca var. spmeanwn Burck E. coca var. nouogranatense Morns -
E. boliuianum Burck E. coca var. spruceanum Burck
Holmes, 1892 E. coca Lam. E. coca var. spruceanum Burck E. coca var. nouogranatense Morris
E. boliuianum Burck
J. D. Hooker, 1894 E. coca Lam. E. coca var. nooogranatense Morris
E. coca var. spruceanurn Burck
~ -
Hieronymus, 1895 E. coca Lam. E. nouogranatense (Morris) Hieron
Schneider. 1898 E. coca Lam. Brazilian coca E. coca var. nouogranatense Morris Trujillo Coca
E. boliaianum Burck E. coca var. spruceanurn Burck
Rusby, 1900 E. coca Lam. E. coca Lam E. carthageneme Jacq. E. truxillense Rushy
~

Holmes. 1901 E. coca Lam. “E. novogranatense Morris”* “E. spruceanurn Burck”
“E. spruceanurn Burck”
Mortimer, 1901 E. coca Lam. “E. Spruceanum Burck” E. coca Lam. E. coca var. nouogranatense Morris
- ~

Holmes, 1910 E. coca Lam. E. truxillense Rushy

Schulz. 1907b E. coca Lam. E. coca Lam. E. nouogranatense (Morris) Hieron E. novogranatense (Morris) Hieron.
E. nouogranatense var. rnisrophyllum
0. E. Schulz
E. nouogranatense var. tobagense 0.
E. Schulz
Payens, 1958 E. coca Lam. - E. nouogranatense (Morris) Hieron. E. nouogranatenre (Morris) Hieron.
~

Gentner, 1972 E. coca Lam. E. nowgranatense (Morris) Hieron. E. novogranafense (Morris) Hieron.
Machado, 1972 E. coca Lam. E. m a Lam. - “ E . nouogranatense var. truxillense
E. chilpri E. Machado (Rushy) E. Machado”
E. hardinii E . Machado
Tyler et a[.. 1977 E. coca Lam. var. coca - E. coca var. novogranafense Morris E. coca var. spruceanwn Burck
E. coca var. spruceanurn Burck
Plowman, 1980b E. coca Lam. var. coca E. coca var. ipadu Plowman E. nouogranatense (Morris) Hieron. E. nouogranatense var. truxillense
W
var. nowgranatense (Rushy) Plowman e
~~

*The use here of quotation marks indicates a nomenclatural combination which is not validly published or is incorrectly cited in the original publication.
350 T. PLOWMAN

traditional manner. Only very recently have outside entrepreneurs begun to

cultivate Amazonian coca as a source of illicit cocaine (Anonymous, 1980a, b, c) .
Erythroxylum novogranatense var. novogranatense, known as Colombian coca, is
distinguished from E. coca by a series of characters which encompass morphology,
chemistry, breeding systems, anatomy, ecology and geographic distribution. It is
known to be native to Colombia and Venezuela and is probably the kind of coca
cultivated in pre-Conquest times in Central America. Erythroxylum novogranatense
var. novogranatense, unlike E . coca var. coca, is not known outside cultivation and has
not been found in feral or semi-wild populations. It is employed for chewing only
by certain remote Indian tribes in the Colombian mountains, and is only a minor
source of coca for the production of cocaine.
This variety shows-considerabletolerance to drought and is grown commonly in
the drier, mountainous areas of Colombia. It is also remarkably adaptable to
varying ecological conditions. Unique among the cultivated cocas, E. novogranatense
var. novogranatense is partially self-compatible and produces abundant seed in
cultivation. For these reasons, this species has been widely distributed throughout
the Old and New World tropics and flourishes in both wet and dry areas, in
mountainous regions and at sea level. The facility of cultivation and propagation
of E. novogranatense var. novogranatense is undoubtedly the reason for its early
appearance in the European horticultural trade in the late 19th century, resulting
in its debut as the famous ‘Kew Plant’ in England and its later appearance as ‘Java
coca’ in the East Indies (Plowman, 1979).
Trujillo coca is now considered to be a variety of Colombian coca, designated
Erythroxylurn novogranatense var. truxillense (Rusby) Plowman (Plowman, 1980a, b) .
Although it is intermediate in some characters between E. coca var. coca and E.
novogranatense var. novogranatense, Trujillo coca shows stronger affinities with the
latter, based on its morphology, anatomy, flavonoid chemistry, ecological
tolerances and breeding relationships (Plowman, 1979; Rury, 1981; Bohm et al., in
press).
Trujillo coca is cultivated in arid areas in northern Peru, along the western
slopes of the Andes and in the dry, upper Maraiion valley. Like E. novogranatense
var. novogranatense, Trujillo coca is not known outside cultivation and, despite its
great tolerance to drought, needs some irrigation for survival. It may be considered
a true cultigen.
Trujillo coca is highly prized by coca chewers for its excellent flavour and
substantial cocaine content. However, owing to the difficulty of extracting and
crystallizing the pure alkaloid, a fact pointed out in the 19th century, Trujillo coca
is little used for illicit cocaine production. However, this variety is especially high
in flavouring compounds such as methyl salicylate, and has long been used in the
manufacture of coca-flavoured beverages and wines. Today, much of the Trujillo
coca crop is consumed in the manufacture of de-cocainized extracts for flavouring
the ubiquitous soft drink Coca Cola.
Although it grows in fairly accessible areas along the Peruvian coast, herbarium
specimens of Trujillo coca were not collected until 1914 (Plowman, 1980b). With
only isolated leaf specimens and without any knowledge of the specialized cultural
conditions of Trujillo coca, it is not surprising that its identification long remained
problematical. Still, even the commercial leaves were early associated with
Erythroxylum novogranatense by Morris ( 1889) and indirectly by Rusby ( 1900).
The first attempt to recognize Trujillo coca as a taxonomic variety of E.
 COCA 35 1

novogranatense was made by Machado ( 1972),who personally studied and collected

Trujillo coca in Peru. However, this name was invalidly published; the correct and
valid name for Trujillo coca, E. novogranatense var. truxillense (Rusby) Plowman,
was not published until 1980 (Plowman, 1980a).

ACKNOWLEDGEMENTS

Part of the research reported in this paper was conducted at the Botanical
Museum of Harvard University under a contract with the U S . Department of
Agriculture (No. 12-1+1001-230). Financial support was also provided by a
grant from the National Institute of Drug Abuse (No. 5 R01 DA02210-02). I am
grateful to Dr F. Lipp for furnishing information about the life and work of H. H.
Rusby, to Mr S. M. Rossi for searching for coca specimens among Rusby’s
collections at the Harvard Botanical Museum, and to Professor R. E. Schultes for
providing access to these collections. I would like to thank the following persons
who assisted in locating obscure references and illustrations: Dr G. Davidse, Messrs
M. Slater, M. Calhoun, J. Shaw and J. Zarucchi. The libraries of Harvard
University, Missouri Botanical Garden and Field Museum supplied copies of early
coca illustrations. I am especially indebted to Mrs H. Maas and Dr P. J. M. Maas
of Utrecht for making careful translations from Dutch of critical papers. I am also
grateful to Drs M. Nee, J. Engel and A. T. Weil and to Mr P. Matekaitis for
offering valuable criticism of the manuscript. I would like to thank the curators of
the following herbaria who kindly lent specimens necessary for this study : BM,
BO, C, ECON, F, G, GH, K, MICH, NY, P, U, US, USM, W.

APPENDIX

LOCATION AND IDENTITY OF HERBARIUM SPECIMENS OF

ERYTHROXYLUM MENTIONED IN THE TEXT*
Burck, W., 9, E. novogranatense var. novogranatense, TYPE of E. coca var. spruceanurn
Burck (BO).
Economic Museum of New York Bot. Gard., acc. 2684, E. novogranatense var.
truxillense, LECTOTYPE of E. truxillense Rusby (ECON, F, NY, USM).
Eggers, H. F. A., 5831, E. novogranatense var. novogranatense, TYPE of E. novogranatense
var. tobagense 0. E. Schulz (K).
Glaziou, A. F. M., 18160, E. novogranatense var. novogranatense, TYPE of E.
novogranatense var. rnicrophyllurn 0 . E. Schulz (C, K, P).
Goudot, J., s.n., E. novogranatense var. novogranatense (G, P).
Hart, J. H., 5830, E. novogranatense var. novogranatense (G, NY, P, W).
Jussieu, J. de, s.n., E. coca var. coca, TYPE of E . coca Lam. (P).
Kew, Royal Botanic Gardens, s.n., 1887, E. novogranatense var. novogranatense, TYPE
of E. coca var. novogranatense Morris (K); s.n., 1893, E. coca var. coca (K).
Lehmann, F. C., 4737, E. novogranatense var. novogranatense (F, GH, K, P, US).
*Herbarium abbreviations are taken from Holmgren & Keuken (1974) Index Herbariorum, 6th ed.
3.52 T. PLOWMAN

Linden, J. J., 1181, E. novogranatense var. novogranatense (P).

Pulle, A., s.n., E. coca var. coca, representative specimen o f E. bolivianum Burck (U).
Purdie, W., s.n., E. novogranatense var. novogranatense (K).
Rusby, H. H., 2076, E. gracilipes (MICH, NY) ;2078, E. ulei (MICH, NY) ; 2080, E.
anguijiugum (MICH, NY) ; s.n., 1900, E. novogranatense var. novogranatense (NY).
Rusby, H. H., & Squires, R. W., 167, E. recurrens (K, NY).
Spruce, R., 73, E. coca var. ipadu (K);3725, E. recurrens, T Y P E o f E .novogranatense var.
macrophyllum 0 . E. Schulz (K).
Triana, J. J., s.n., E. novogranatense var. novogranatense (BM, K, P).

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