The Cycad Pages
Cycas orientis

Cycas orientis K.D. Hill, "Telopea 5(4): 696-697, fig. 3" (1994). H—NSW
"TYPE: Australia, Northern Territory, 48.9 km E of Badalngarrmirri Creek, K.D. Hill 3936 & L. Stanberg, 26 Aug 1991 (holo NSW; iso CANB, DNA)."[NSW][NSW]

Etymology: From the Latin orientis, of the east, referring to the occurrence in the east of Arnhem Land.

Illustration: Hill 1994, fig. 3.

Distinguishing features: Distinguished by the midgreen leaves with relatively long petioles and flat leaflets with the midrib more prominent beneath. Leaves in general resemble those of C. armstrongii, which differs in having the midrib equally prominent on both sides of the leaflets. C. armstrongii also has a generally smaller stature with more slender stems and shorter leaves with shorter petioles.

Distribution and habitat: Locally abundant on deep white to yellow sands over laterites, mainly in Eucalyptus tetrodonta - E. miniata dominated savanna forests, but occurring in most nonswampy habitats, widespread in eastern Arnhem Land. Intergradation occurs with C. arnhemica where the ranges adjoin.

Conservation status: Abundant and widespread, not considered to be at risk. Although not reserved, the extreme abundance of this species would buffer it from any threat in the medium term. Almost all populations are on aboriginal land, and conservation issues on such land are yet to be fully addressed. The inhibition of reproduction by too-frequent fire is one such issue.


Stems arborescent, to 4(-7) m tall, 8-14 cm diam. at narrowest point.

Leaves bright green, highly glossy, 55-125 cm long, flat (not keeled) in section (opposing leaflets inserted at 160-180° on rachis), with 130-180 leaflets, with white tomentum shedding as leaf expands. Petiole 17-35 cm long, glabrous, unarmed (rarely with few distal spines). Basal leaflets not gradually reducing to spines.

Median leaflets simple, weakly discolorous, 60-160 mm long, 4.5-7 mm wide, inserted at 50-80° to rachis, decurrent for 2-3.5 mm, narrowed to 3-5 mm at base (to 50-80% of maximum width), 5-10 mm apart on rachis; median leaflets section flat; margins flat; apex aristate, not spinescent; midrib raised above (slightly), raised below.

Cataphylls linear, pungent, pilose, 4-8 mm long, persistent.

Pollen cones ovoid, orange, 20 cm long, 8 cm diam.; microsporophyll lamina firm, not dorsiventrally thickened, 25 mm long, 14 mm wide, fertile zone 20 mm long, sterile apex 6 mm long, deflexed, apical spine prominent, sharply upturned, 10 mm long.

Megasporophylls 14-24 cm long, grey-tomentose and brown-tomentose; ovules 1-4, glabrous; lamina lanceolate, 40-90 mm long, 15-25 mm wide, regularly dentate, with 10-24 pungent lateral spines 1-5 mm long, 1 mm wide, apical spine distinct from lateral spines, 14-63 mm long.

Seeds flattened-ovoid, 25-36 mm long, 25-34 mm wide; sarcotesta orange-brown, slightly pruinose, 3-4 mm thick; fibrous layer absent; sclerotesta smooth. Spongy endocarp absent.

The Cycad Pages

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Written and maintained by Ken Hill 1998-2010
Maintained by Leonie Stanberg and Dennis Stevenson 2010-2012
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