| Boswellia hesperia Thulin, M.H.Weber & Rzepecky, in Thulin, Weber, Mubarak et Rzepecky, 2025. |
Abstract
The new species Boswellia hesperia Thulin, M.H.Weber and Rzepecky is described, illustrated and mapped. It is a dwarf tree, restricted to westernmost Socotra (Yemen), growing on limestone rocks, in which the usually prostrate stems tend to fill out holes and crevices. It differs from B. nana Hepper, another dwarf tree endemic to Socotra but restricted to the easternmost parts of the island, by having leaves densely pubescent with whitish hairs beneath and by its smaller flowers and fruits.
Keywords: dwarf tree, frankincense, taxonomy, Yemen
| Boswellia hesperia sp. nov. from mountain ridge above Neet, 5–6 km from the coast, Socotra, 18 May 2021. (A) plant filling out crevice in limestone rock, leafless, showing reddish white flowers and fruits, (B) leafless plant with flowers and fruits. Photographs by Alain Rzepecky. |
| Boswellia hesperia sp. nov. from the type locality above Neet in Socotra, 30 Apr. 2023. (A) plant showing upper surfaces of leaves and 5- or 4-merous flowers with reddish white petals, (B) flowers, showing calyx and outside of petals, and undersides of leaves with dense indumentum of crisped whitish hairs, (C) plant showing 3-locular fruit. Photographs by Michael Weber. |
| Boswellia hesperia sp. nov. from above Neet, Socotra, 17 May 2024. (A) plant showing flower and 4-locular fruits, (B) plant showing 4-merous flowers with cream or whitish petals, (C) plant showing 3-merous flower with whitish petals. Photographs by Michael Weber. |
| Boswellia hesperia sp. nov. (A) flower, top view, (B) detail of petal margin, (C) flower, side view, (D) fruit, (E) pyrene, ventral view, (F) pyrene, dorsal view, (G) leaf from short shoot, upper side, (H) leaf from short shoot, lower side, (I) leaf from long shoot, upper side, (J) portion of plant with leaves, (K) long shoot, (L) seedling, showing lobed cotyledons. Drawing by Alain Rzepecky. |
| Boswellia hesperia sp. nov., plant filling out hole in limestone rock, showing leaves and reddish flowers; above Neet, Socotra, 31 Oct. 2007. Photograph by Lisa Banfield. |
Boswellia hesperia Thulin, M.H.Weber and Rzepecky, sp. nov.
A dwarf tree similar to Boswellia nana Hepper, but differing by having leaves densely pubescent with ± crisped whitish hairs (versus glabrous or subglabrous) beneath, smaller flowers with petals 3–4 mm (versus 4.5–5.5 mm) long and smaller fruits (5–7 mm versus ca 10 mm long).
Etymology: The epithet ‘hesperia' (Latin, western) refers to the distribution of this species that is restricted to the westernmost part of Socotra.
Mats Thulin, Michael Weber, Sami Ali Mohammed Mubarak and Alain Rzepecky. 2025. Boswellia hesperia sp. nov. (Burseraceae) from Socotra. Nordic Journal of Botany. DOI: doi.org/10.1111/njb.04728