Current name and circumscription
Euphorbia tortilis Rottler ex Ainslie is accepted by Plants of the World Online. The name was published in 1826. POWO records its native range in southern India and north-central Sri Lanka. The detailed morphological comparisons in the two studies discussed here concern Indian material [2-WWW] [De Jong et al. 2026] [Naidu and Kusom 2026].
The name has sometimes been applied to plants identified mainly by their twisted stems. The description of E. costatoalata associated a distinct combination of stem, cyathium and seed characters with a separate species. A subsequent paper described E. sankarensis, E. bahalita and the botanical variety E. tortilis var. mysorensis. These are separately defined taxa. An older identification of a particular specimen as E. tortilis requires examination of its characters and origin [De Jong et al. 2026] [Naidu and Kusom 2026].
Characters used in identification
In the comparison by De Jong and colleagues, typical E. tortilis had closely packed, strongly spiralled stem segments, usually with three wings and occasionally four. The surface between the wings generally lacked pronounced ribbing. Teeth along the wing margins followed the stem spiral. The seedlings examined lacked the mottling between the wings reported for E. costatoalata [De Jong et al. 2026].
The cyathia, inflorescences containing small reduced flowers, have oblong glands with a flat profile. In the comparative material, styles were united along their lower third. Capsules had pronounced corners and a slightly rounded upper surface. Seeds were described as slate grey. These characters complement overall habit because wing number and stem-segment length partly overlap with the ranges found in similar taxa [De Jong et al. 2026] [Naidu and Kusom 2026].
The importance of reference material
De Jong and colleagues compared the new plants with the neotype of E. tortilis held at herbarium MH and with specimens from several Tamil Nadu localities. A neotype is a specimen designated as the reference for a name when a replacement nomenclatural type is needed. Plants from several sites were also observed in a shared garden. Naidu and Kusom re-examined material from Tanjavur against historical descriptions. These comparisons connect a name with specific specimens and a defined set of characters [De Jong et al. 2026] [Naidu and Kusom 2026].
Related articles
Nomenclature in the WCVP 16 inventory
Nomenclatural data from the edition of 4 June 2026 [27-WWW].
- Order
- Malpighiales
- Rodzina
- Euphorbiaceae
- Genus
- Euphorbia
- First publication of the name
- Materia indica 2 — 424 (1826)
Related plant cards
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