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| The Cycad Pages
| | Cycas semota
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- Cycas semota K.D. Hill, Telopea 7(1): 44?? (1996). H—NSW
- TYPE: Australia, Queensland, Bamaga district, K.D. Hill 4708 & L. Stanberg, 10 Jul 1994 (holo NSW; iso BRI, CANB, DNA, K, L, MEL, NY).
[NSW]
[NSW]
[NSW]
[NSW]
Etymology:
From the Latin semotus, remote or distant, in reference
to the occurrence of this taxon in the farthest extremity of Cape
York Peninsula.
Illustration:
Hill 1996, fig. 11.
Historical notes:
Apparently first collected in 193- and given the name C. normanbyana.
Distinguishing features:
Readily distinguished among the Australian species
by the short megasporophylls and short, soft cataphylls with short,
close indumentum. C. tuckeri from farther south has even
shorter megasporophylls, with a distinctly shorter and broader
lamina. The type of C. normanbyana has a similarly attenuate
megasporophyll lamina, but a much longer overall megasporophyll.
Cataphylls and leaflets of the latter also differ (see C. media
subsp. media).
Distribution:
locally abundant, but apparently restricted
to the Bamaga district in far northern Cape York Peninsula. The
known habitat is in grassy understorey of eucalypt forest with
Corymbia novoguinensis, C. tessellaris and Erythrophleum
chlorostachys. This forest is relatively moist, and often
forms a mosaic with mesophyllous forest, on shallow sandy soils
over massive laterite.
Conservation status:
highly localised and not conserved.
All specimens known are from the one population near the town
of Bamaga, and under threat for that reason. 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.
Description:
Stems arborescent, to 5 m tall.
Leaves bright green, semiglossy, 110-150 cm long, moderately keeled (opposing leaflets inserted at 100-130° on rachis), with 140-250 leaflets, with orange or brown tomentum shedding as leaf expands; rachis consistently terminated by paired leaflets. Petiole 32-39 cm long (25-30% of total leaf), petiole glabrous, unarmed or spinescent for 10-15% of length. Basal leaflets not gradually reducing to spines, 8-140 mm long.
Median leaflets simple, strongly discolorous, 140-195 mm long, 6.5-7.5 mm wide, inserted at 50-70° to rachis, decurrent for 2-4 mm, narrowed to 3-4 mm at base (to 45-65% of maximum width), 8-11 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, 60-80 mm long, persistent.
Pollen cones ovoid, brown, 40-46 cm long, 12-14 cm diam.; microsporophyll lamina firm, not dorsiventrally thickened, 46-56 mm long, 12-16 mm wide, fertile zone 34-40 mm long, sterile apex 14-17 mm long, level, apical spine prominent, gradually raised, 8-10 mm long.
Megasporophylls 13-20 cm long, brown-tomentose; ovules 2-8, glabrous; lamina lanceolate, 60-75 mm long, 20-28 mm wide, regularly or obscurely dentate, with 28-46 pungent lateral spines 0-7 mm long, 1-2 mm wide, apical spine distinct from lateral spines, 25-40 mm long, 3-4 mm wide at base.
Seeds flattened-ovoid; fibrous layer absent; sclerotesta smooth. Spongy endocarp absent.