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The Cycad Pages
Encephalartos dyerianus

Encephalartos dyerianus Lavranos & D.L. Goode, Bull. Jard. Bot. Belg. 58: 219-224 (1988). H—PRE
"TYPE: Republic of South Africa, Transvaal, farm Lilie, N of Mica, in the Lowveld, on a single granite hill alt ca 700 m, Feb 1966, J. Smit s.n., PRE 32864 (holo PRE)."


Etymology: Honoring 20th Century South African botanist R. Allen Dyer, student and monographer of the South African cycads.

Literature:

Illustrations:

Vernacular:

Historical notes: Described in 1988 by South African botanists - Lavranos and Douglas Goode, who recognised that the blue-leaved Transvaal cycads previously all included in E. eugene-maraisii fell into a number of clearly morphologically distinct and geographically separated populations (see also E. dolomiticus and E. middelbergensis). Similar observations were published more or less simultaneously by Robbertse et al. (1990), resulting in creation of the redundant names E. graniticola and E. verrucosus. E. hirsutus is another more recently recognised member of this group.

Distinguishing features: Distinguished within a group of blue-leaved Transvaal species by the straight leaves sometimes with slightly twisted or recurved tips, the leaflets usually with 1-2 spines on each margin, the lower about 6 pairs of leaflets reducing in size and becoming divided, no clear petiole, and yellow, glabrous cones. This group of species is distinguished from the blue-leaved species of the Cape Province (E. lehmannii and allies) by the almost concolorous leaves with stomata on both surfaces.

Distribution and habitat: Known from a single granite mountain in north-eastern Transvaal Province, South Africa, in open shrubland and grassland on slopes.

Conservation: 1997 IUCN Red List of Threatened Plants category E.

Description:

Plants arborescent; stem 4 m tall, 60 cm diam.

Leaves 140-170 cm long, blue or silver, dull, moderately keeled (opposing leaflets inserted at 90-120° on rachis); rachis blue, straight, stiff, slightly twisted in some leaves; petiole straight, with 1-6 prickles; leaf-base collar prominent; basal leaflets reducing to spines.

Leaflets lanceolate, concolorous, not overlapping, not lobed, insertion angle obtuse (45-80°); margins flat; upper margin lightly toothed (1-3 teeth); lower margin lightly toothed (1-3 teeth); median leaflets 17-24 cm long, 13-18 mm wide.

Pollen cones 5-8, narrowly ovoid, bluish-green to yellow, 30-50 cm long, 9-12 cm diam.

Seed cones 1-5, ovoid, blue-green to yellow, 30-60 cm long, 10-20 cm diam.

Seeds oblong, 40-45 mm long, 25-30 mm wide, sarcotesta yellow to orange-brown.


The Cycad Pages

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Written and maintained by Ken Hill 1998-2010
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