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

WCVP records “cultigen from S. Jordan”; a separate structured distribution field records “Palestine”. The wild origin is explicitly reported as unknown in Carter et al. (2011). [2] [1]

Habitat

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

Relationships

Its parent taxon is A. porphyrostachys and the other accepted subspecies is subsp. porphyrostachys. Carter et al. (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]

Classification and nomenclature

Classification: 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

Etymology

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.
McCoy, T. (2019). The Aloes of Arabia. McCoy Publishing, Temecula, California. pp. 297, 300–301.