Etymology: Latin arenarius, sandy, from the habitat on relic beach dune deposits of deep sand. Literature: Illustrations: Vernacular: Historical notes: Described in 1956 by South African botanist R. Allen Dyer. Distinguishing features: Distinguished by the short stems, seldom more than 1 m in height, the slightly dull silver or grey sheen of adult leaves, and the leaflets with lobes on the lower margins only. It is most similar to E. latifrons, which has taller stems and mid to deep green glossy leaves. Median leaflets of E. latifrons are closely crowded, overlapping and twisted out of the leaf plane, but clearly spaced and untwisted in E. arenarius. Distribution and habitat: Restricted to a small area near Alexandria in eastern Cape Province, South Africa, in dense mixed shrubland on deep sand of old beach dune systems. Encephalartos altensteinii grows nearby, and one or two suspected hybrids are known. Conservation: 1997 IUCN Red List of Threatened Plants category E. Description:
Plants arborescent; stem 1 m tall, 20-30 cm diam. Leaves 100-150 cm long, blue or silver, semiglossy, moderately keeled (opposing leaflets inserted at 120-150° on rachis); rachis green, gently curved, somewhat lax, not spirally twisted; petiole straight, with no prickles; leaf-base collar not present; basal leaflets not reducing to spines. Leaflets ovate, weakly discolorous, overlapping downwards, with 2-3 lobes on most leaflets, insertion angle horizontal to obtuse (45-80°); margins flat; upper margin lightly toothed (1-3 teeth); lower margin lightly toothed (1-3 teeth); median leaflets 12-16 cm long, 30-40 mm wide. Pollen cones 1, narrowly ovoid, green, 30-50 cm long, 8-15 cm diam. Seed cones 1, ovoid, green, 50-60 cm long, 25-30 cm diam. Seeds ovoid, 40-50 mm long, 20-25 mm wide, sarcotesta red.
|
