Aloe inermis

Overview

Aloe inermis Forssk. is currently accepted by WCVP. WCVP currently lists Somalia, Oman, Saudi Arabia and Yemen for the species, while its summary range is southern Saudi Arabia to western Oman. McCoy (2019) and Carter et al. (2011) treat the species as Yemen-centered. Plants form clumps with decumbent to ascending stems and have conspicuously toothless leaves. [1, 2, 3, 4]

Key characteristics

Growth form

Plants sucker into small to large groups; stems are decumbent, sprawling or ascending to erect and may reach 50 cm. [2, 3]

Leaves

Leaves are rosulate, lanceolate to ensiform and attenuate, spreading and becoming recurved or decurved. [2, 3]

Leaf surface and margin

The leaf surface is rough; the margin is entire and toothless. [2, 3, 4]

Inflorescence and flowers

The inflorescence is oblique to suberect and about 70 cm long, with widely spreading branches; the lowest branch may rebranch. Flowers have a cylindrical-trigonous perianth. [2, 3]

Distribution

WCVP currently lists Somalia, Oman, Saudi Arabia and Yemen, with the summary range given as southern Saudi Arabia to western Oman. This is broader than the Yemen-centered treatments in McCoy (2019) and Carter et al. (2011). McCoy (2019) describes A. inermis as endemic to Yemen, and Carter et al. (2011) also give a Yemen-centered range. [1, 2, 3]

Habitat

McCoy (2019) records weathered basalt and other volcanic substrates on gravelly plains, rocky hillsides and fissures, in a low and erratic rainfall rain-shadow zone. Carter et al. (2011) likewise record rocky slopes on ancient volcanic or basement rocks around Taizz. [2, 3]

Etymology

The epithet inermis is Latin for “unarmed” and refers to the entire, toothless leaf margin. [2, 4]

Classification and nomenclature

Accepted name: Aloe inermis Forssk. [1]
Protologue bibliography: Published in Flora Aegyptiaco-Arabica: 74 (1775). [1]
Type locality and type material: McCoy (2019) and Carter et al. (2011) cite Forsskål s.n. from Taizz, Yemen, with the specimen at C (Copenhagen; source notation differs slightly). [2, 3]

Main references

World Checklist of Vascular Plants (WCVP).
McCoy, T. (2019). The Aloes of Arabia. McCoy Publishing, Temecula, California.
Carter, S., Lavranos, J.J., Newton, L.E. & Walker, C.C. (2011). Aloes: The Definitive Guide. Royal Botanic Gardens, Kew.
Grace, O.M., Klopper, R.R., Figueiredo, E. & Smith, G.F. (2011). The Aloe Names Book. Strelitzia 28. South African National Biodiversity Institute, Pretoria.

Updates

Classification, distribution and descriptive information are revised as new sources are verified or taxonomic treatments change.