The Cycad Pages
Cycas desolata

Cycas desolata P.I. Forst., "Austrobaileya 4(3): 345-352, figs. 1-5" (1995). H—BRI
"TYPE: Australia, Queensland, north-west of Charters Towers, P.I. Forster 14671B (male), 27 Jan 1994 (holo BRI)."

Etymology: From

Illustration: Forster 1995, figs 1-5.

Historical notes:

Distinguishing features: distinguished from other Australian species by the strongly glaucous, light blue leaves with relatively few leaflets, and the spine-free petioles.

Distribution: known only from two populations near Charters Towers.

Conservation status: Known only from small populations on grazing land. 1997 IUCN Red List of Threatened Plants category R. ROTAP category 2V-.


Stems arborescent, to 4(-7) m tall, 15-25 cm diam. at narrowest point.

Leaves blue, dull, 75-120 cm long, strongly keeled (opposing leaflets inserted at 30-50° on rachis), with 90-136 leaflets, with orange or brown tomentum shedding as leaf expands; rachis usually terminated by paired leaflets. Petiole 10-23 cm long, glabrous, unarmed.

Median leaflets simple, strongly discolorous, 180-210 mm long, 3.5-5 mm wide, inserted at 40-50° to rachis, decurrent for 2-4 mm, narrowed to 2.5-4 mm at base (to 70-80% of maximum width), 1-5 mm apart on rachis; median leaflets section flat; margins recurved; apex acute, spinescent; midrib flat above, raised below.

Cataphylls linear, soft, densely floccose, 30-45 mm long, persistent.

Pollen cones narrowly ovoid, orange or brown, 24-40 cm long, 8-9.5 cm diam.; microsporophyll lamina firm, not dorsiventrally thickened, 28-38 mm long, 5-13 mm wide, fertile zone 20-26 mm long, sterile apex 8-12 mm long, deflexed, apical spine prominent, sharply upturned, 3-4 mm long.

Megasporophylls 13-24 cm long, brown-tomentose; ovules 2-6, glabrous; lamina ovate, 28-32 mm long, 20-25 mm wide, obscurely dentate, apical spine distinct from lateral spines, 5-15 mm long.

Seeds flattened-ovoid, 35-39 mm long, 32-35 mm wide; sarcotesta yellow or orange-brown, strongly pruinose; fibrous layer absent; sclerotesta smooth. Spongy endocarp absent.

The Cycad Pages

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Written and maintained by Ken Hill 1998-2010
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