From the Greek oxys = sharp, sour or acid and (h)als = salt. The plant is frequently consumed for its sour taste caused by the oxalic acid, particularly the flowering stalks of O. pes-caprae. In large quantities the oxalic acid inhibits digestion and in stock leads to the condition 'dikpens' or bloated belly.
Celtic. sel = sight; jach = salutary, beneficial; referring to its supposed medicinal properties, especially for diseases of the eyes. Another source suggests the derivation is Greek, selagh = flashing. (Allusion unknown.)
For Johannes Bodaeus van Stapel (1602–1636), Dutch physician and botanist. He received a medical degree in 1625 from Leiden University and studied botany under Adolphus Vorstius. His life’s ambition was to publish an annotated edition of the botanical works of Theophrastus (370–287 BCE), but he died before the book was finished. The content was edited and published by his father as Theophrasti Eresii de Historia Plantarum in 1644. One of the plants in the book, drawn by Justus Heurnius (1587–1653) from his brief stay at the Cape in 1624, was Fritillaria crassa (Stapelia variegata), now known as Orbea variegata. The genus was named Stapelia in 1753 by Linnaeus in his Species Plantarum.