c.1840, Hosking, "Architecture" in Encyclopædia Britannica, III 470:
Stele. The ornaments on the ridge of a Greek temple, answering to the antefixæ on the summit of the flank entablatures, are thus designated.
Usage notes
Although stela and stele were used in antiquity for pillars and columns generally, and continued to carry that meaning when their use was revived in English archaeology and architecture in the 18th and 19th century, respectively, present usage usually distinguishes obelisks, columns, shafts (the body of a column between the capital and the pediment), etc., from stela and stele, which are used to refer to engraved slabs or small pillars.
The terms do sometimes refer to undecorated rocks when they have been raised by artificial means in prehistoric times, particularly when they are slab-like, but the large Neolithic menhirs are usually distinguished as are Chinese scholar's rocks or Taihu rocks, and other modern uses of upright stones as decoration or signage.
Stele is frequently pluralized irregularly as stelae, which is also used as a plural form of the more Latinized singular form stela. The anglicized Greek plural stelai has been used since the late 19th century but is less common than steles.
1895, Sydney Howard Vines, A Students' Text-book of Botany, section 179:
The stele may have—in different structures—one to many protoxylem (primitive wood) groups, and is accordingly described as monarch...diarch...triarch...tetrarch...polyarch.
1898, Eduard Strasburger et al., translated by Hobart Charles Porter, A Text-book of Botany, section 109:
The so-called central cylinder, for which Van Tieghem has proposed the name stele (column).