Aloe porphyrostachys subsp. koenenii

Overview

Aloe porphyrostachys subsp. koenenii is a freely suckering aloe with decumbent stems, glaucous-green leaves tinged purple, and tall branched inflorescences bearing cylindrical racemes of bright carmine-red flowers. It is well documented from the Petra population, but the source literature explicitly states that its wild origin is unknown. [1]

Key characteristics

Growth form

Freely suckering and forming dense, extensive groups, with decumbent stems. [1]

Leaves

Leaves are erect or ascending, glaucous-green with a purplish tinge; young plants may be white-spotted. [1]

Leaf margin

The margins bear hard teeth with brown tips. [1]

Inflorescence

The inflorescence is tall and branched; cylindrical racemes are fairly densely flowered, with the open flowers reflexed and held against the axis. [1]

Flowers

Flowers are bright carmine-red; the perianth is cylindrical-ventricose and constricted at the mouth, and the stamens and style are exserted. [1]

Distribution

A population is documented at Petra, Jordan, but Carter et al. (2011) state that the wild origin of this taxon is unknown. WCVP records “cultigen from S. Jordan” and separately records “Palestine”; these records do not establish a native distribution. [2] [1]

Habitat

At Petra, plants are recorded on rock slopes and ledges of vertical cliffs above the ancient city, growing on sandstone. [1]

Diagnostic features

(2011) note very similar racemes and flower structure, but describe A. porphyrostachys as the larger plant, with longer, less rigid leaves, more inflorescence branches, and longer racemes, floral bracts and flowers. [2] [1]

Scientific name and synonyms

Classification and nomenclature: Accepted as Aloe porphyrostachys subsp. koenenii, a subspecies of A. porphyrostachys. The basionym and homotypic synonym is A. koenenii Lavranos & Kerstin Koch. [2] [3]

Parent taxon: Aloe porphyrostachys
Sibling subspecies: Aloe porphyrostachys subsp. porphyrostachys

Type specimen and type locality

Carter et al. (2011) cite the type as M. Koenen 1/82 (FT) from Petra, Jordan. [3] [1]

Taxonomic treatment

WCVP treats Aloe porphyrostachys subsp. koenenii as an accepted subspecies. [2] [3]

Epithet origin

The epithet koenenii commemorates Manfred Koenen, the German horticulturalist who collected the type in Jordan. [3]

References

Carter, S., Lavranos, J.J., Newton, L.E. & Walker, C.C. (2011). Aloes: The Definitive Guide. Royal Botanic Gardens, Kew. pp. 448–449.
World Checklist of Vascular Plants (WCVP).
Grace, O.M., Klopper, R.R., Figueiredo, E. & Smith, G.F. (2011). The Aloe Names Book. Strelitzia 28. South African National Biodiversity Institute, Pretoria. p. 125.