|Photo C.H. Tsou
|The Cycad Pages
- Cycas taitungensis "C.F. Shen, K.D. Hill, C.H. Tsou & C.J. Chen", Bot. Bull. Acad. Sin. 35: 135-138 (1994). H—HAST
- "TYPE: Taiwan, Taitung Hsien, Yenping, ca. 121 00'E, 22 52'N, elev. ca. 500 m, in the Cycad Reserve, Chi-Hua Tsou 825, 28 Jun 1993 (holo HAST; iso A, BM, K, NSW, NY, P, PE, TAI)."[NY][NY][NY][NY][NY]
From the prefecture of Taitung, a mountainous region in south-eastern Taiwan,
where this species is native, with the Latin termination -ensis,
place of origin.
Cheng, Fu & Cheng 1975,
Li 1980, Wang 1996.
Although not described until 1994, this species was widely known previously
under the misapplied name C. taiwaniana.
Although very close to C. revoluta, this species is readily
distinguished by the longer, flatter leaves with longer, broader
and flatter leaflets. Female cones also tend to be more tightly
imbricate and cabbage-like, and seeds are darker in colour.
Distribution and habitat:
Known only from the mountainous southern parts of Taiwan, growing
on steep to precipitous slopes.
A large stand occurs in a secure nature reserve established specifically
for this cycad.
No immediate threat is evident, although this population is in a
small area in geologically unstable country. This species was listed by the
1997 IUCN Red List of Threatened Plants as category V,
and is currently placed in category VU.
|Photo Ken Hill
|Photo Ken Hill
Stems arborescent, to 3(-6) m tall, 25-30 cm diam. at narrowest point.
Leaves deep green, semiglossy, 100-180 cm long, slightly keeled (opposing leaflets inserted at 120-170° on rachis), with 150-170 leaflets, with orange tomentum shedding as leaf expands; rachis usually terminated by a spine. Petiole 15-20 cm long (15-20% of total leaf), petiole glabrous, spinescent for 50-90% of length. Basal leaflets gradually reducing to spines, 30 mm long.
Median leaflets simple, strongly discolorous, 120-170 mm long, 6-8 mm wide, inserted at 45-60° to rachis, decurrent for 2.5-4.5 mm, narrowed to 2-2.5 mm at base (to 30-45% of maximum width), 4.5-6 mm apart on rachis; median leaflets section slightly keeled; margins recurved; apex acute, spinescent; midrib flat above, raised below.
Cataphylls linear, pungent, densely floccose, persistent.
Pollen cones fusiform, yellow, 35-50 cm long, 8.5-10 cm diam.; microsporophyll lamina waxy, not dorsiventrally thickened, 35-40 mm long, 11.5-15 mm wide, fertile zone 25-30 mm long, sterile apex 4.5-10 mm long, apical spine absent, apex deflexed, 6 mm long.
Megasporophylls 21-26 cm long, brown-tomentose; ovules 2-6, pubescent; lamina orbicular, 100-130 mm long, 80-100 mm wide, deeply pectinate, with 28-36 soft lateral spines 35-45 mm long, 1.5-3 mm wide, apical spine not distinct from lateral spines.
Seeds oblong, 40-45 mm long, 25-30 mm wide; sarcotesta red, slightly pruinose, 1.5-3 mm thick; fibrous layer absent; sclerotesta longitudinally grooved. Spongy endocarp absent.