Photo Ken Hill
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The Cycad Pages
Cycas nongnoochiae

Cycas nongnoochiae K.D. Hill, "Brittonia 51(1): 60-62, fig. 7" (1999). H—NSW
"TYPE: Thailand, Wat Suk Sum Ran, 5 km N of Tak Fa, K.D. Hill 4643 & P. Vatcharakorn, 29 Apr 1994 (holo NSW; iso BKF, K)."[NSW]


Etymology: From the Nong Nooch tropical garden near Pattaya in Thailand, supporters of the study of Thai cycads.

Literature: Tang et al. 1997.

Historical notes: Recognised as a distinct species in the 1990's.

Distinguishing features: the combination of tall arborescent stems and dark, deeply fissured bark distinguish this species. C. nongnoochiae has similar bark and tomentum to C. siamensis, but habit and male and female sporophylls more resemble those of C. clivicola. Leaves are more or less intermediate between the two, and C. nongnochiae may have originated as a hybrid. It is clearly now stabilised and reproducing, and best regarded as a separate species.

Distribution and habitat: known at present only from limestone outcrops near Tak Fa, 15°21'N 100°28'E. This species is locally abundant, in full sun in low scrub on steep limestone bluffs, often growing in crevices in bare limestone.

Conservation status: Apparently quite restricted in occurrence and under some pressure from plant collectors, this species should be regarded as a vulnerable species. IUCN (1994) Red List status VU A2c.
Photo Ken Hill
Photo Ken Hill

Description:

Stems arborescent, to 5 m tall, 10-15 cm diam. at narrowest point; 25-40 leaves in crown.

Leaves grey-green or blue, semiglossy, 80-160 cm long, flat (not keeled) in section (opposing leaflets inserted at 180° on rachis), with 120-200 leaflets, with white tomentum shedding as leaf expands; rachis consistently terminated by a spine 4-21 mm long. Petiole 23-35 cm long (20-30% of total leaf), petiole glabrous, spinescent for 10-50% of length. Basal leaflets gradually reducing to spines, 20-80 mm long.

Median leaflets simple, strongly discolorous, 120-230 mm long, 7-8.5 mm wide, inserted at 65-75° to rachis, decurrent for 4-7 mm, narrowed to 3-4 mm at base (to 40-50% of maximum width), 8-11 mm apart on rachis; median leaflets section flat; margins flat to slightly recurved; apex acute, spinescent; midrib flat above, raised below.

Cataphylls narrowly triangular, soft, pilose, articulated.

Pollen cones narrowly ovoid, yellow or green, 15-28 cm long, 7-10 cm diam.; microsporophyll lamina firm, not dorsiventrally thickened, 22-30 mm long, 14-19 mm wide, fertile zone 15-25 mm long, sterile apex 5-7 mm long, level, apical spine prominent, sharply upturned, 7-9 mm long.

Megasporophylls 16-19 cm long, white-tomentose to yellow-tomentose; ovules 2-4, glabrous; lamina orbicular to ovate, 85-100 mm long, 60-70 mm wide, deeply pectinate, with 36-52 soft lateral spines 20-24 mm long, 2 mm wide, apical spine distinct from lateral spines, 15-25 mm long, 4 mm wide at base.

Seeds flattened-ovoid, 35 mm long, 28-35 mm wide; sarcotesta yellow, not pruinose to slightly pruinose, 2 mm thick; fibrous layer present (weakly developed); sclerotesta smooth. Spongy endocarp absent.


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Written and maintained by Ken Hill 1998-2010
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