Photo Ken Hill
The Cycad Pages
Cycas tuckeri

Cycas tuckeri K.D. Hill, "Telopea 7(1): 20-23, fig. 10" (1996). H—NSW
"TYPE: Australia, Queensland, Coen district, K.D. Hill 4683 & L. Stanberg, 7 Jul 1994 (holo NSW; iso BRI, CANB, DNA, K, L, MEL, NY)."[NSW][NSW]

Photo Ken Hill
Etymology: The epithet honours the late Robert Tucker, former director of the Parks and Gardens Department, Townsville, and a keen naturalist and horticulturist who spotted this plant and recognised its distinctive nature.

Illustration: Hill 1996, fig. 10.

Historical notes: ALthough poorly collected botanically, this plant was recognised as possibly different in the 1970's.

Distinguishing features: readily distinguished among the Australian species by the very short megasporophylls. Only C. semota from the northern tip of Cape York Peninsula has comparably short megasporophylls, but those of the latter are distinctly longer, and the lamina is longer and narrower. The very short, soft and finely sericeus cataphylls are also distinctive, as is the relatively broad and short megasporophyll lamina.

An extensive population showing evidencce of introgressive hybridisation wirh C. xipholepis is known on low hills south of Coen.

Distribution: Extremely localised and restricted, known at present only from the one population at the type locality. This species occurs in low open savanna woodland dominated by Eucalyptus cullenii, on gritty soils on stony granite slopes.

Conservation status: Further study is required urgently to establish the status of this taxon, but current knowledge would indicate that it is a rare species, potentially at risk. A ROTAP category of 2V- appears appropriate.
Photo Ken Hill


Stems arborescent, to 5 m tall.

Leaves deep green, semiglossy, 95-150 cm long, moderately keeled (opposing leaflets inserted at 90-140° on rachis), with 108-200 leaflets, with orange or brown tomentum shedding as leaf expands; terminated by paired leaflets or a spine 2-7 mm long. Petiole 20-43 cm long (20-30% of total leaf), petiole glabrous, unarmed. Basal leaflets not gradually reducing to spines, 85-210 mm long.

Median leaflets simple, strongly discolorous, 155-250 mm long, 7-9 mm wide, inserted at 40-50° to rachis, decurrent for 3 mm, narrowed to 2.5-4 mm at base (to 30-45% of maximum width), 10-17 mm apart on rachis; median leaflets section slightly keeled; margins slightly recurved; apex aristate, spinescent; midrib flat above, raised below.

Cataphylls narrowly triangular, soft, pilose, 40-70 mm long, persistent.

Pollen cones ovoid, brown, 30-35 cm long, 13-15 cm diam.; microsporophyll lamina firm, not dorsiventrally thickened, 40-42 mm long, 13-15 mm wide, fertile zone 35 mm long, sterile apex 5-7 mm long, level, apical spine prominent, sharply upturned, 11-16 mm long.

Megasporophylls 10-12 cm long, grey-tomentose or white-tomentose; ovules 2-4, glabrous; lamina ovate, 50-65 mm long, 38-50 mm wide, regularly dentate, with 22-36 pungent lateral spines 3-4 mm long, 1-2 mm wide, apical spine distinct from lateral spines, 19-30 mm long.

Seeds flattened-ovoid, 32 mm long, 28 mm wide; sarcotesta orange-brown, not pruinose or slightly pruinose, 3 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
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