Photo Ken Hill
The Cycad Pages
Cycas guizhouensis

Cycas guizhouensis K.M. Lan & R.F. Zou, Acta Phytotax. Sin. 21(2): 209-210 (1983). H—PE
"TYPE: China, Guizhou: cultivated in hospital of Xingyi (plants originally introduced from Wantun, Xingyi), 10 Aug 1981, K.M. Lan et R.F. Zou 81-8-0001 (holotype in Herb. Guizhou Agr. Coll; iso PE)."

Etymology: From Guizhou province, with the Latin termination -ensis, place of origin.

Literature: Wang 1996

Illustrations: Wang 1996

Historical notes: When described in 1983 by Chinese botanists K.M. Lan and R.F. Zou , this species was contrasted with C. pectinata, although its affinities are actually with the group of Chinese cycads that includes C. balansae and C. taiwaniana. The type was collected by Lan and Zou from a cultivated plant in the grounds of the Xingyi hospital in 1981, although wild collections were also known. Reports of an unidentified species from Longlin county in north-western Guangxi (Sykes 1991) probably refer to this species.

Distinguishing features: Within the group of Chinese cycads with soft pollen cones, loose, freely peeling sarcotesta lacking a fibrous layer and rugose sculpting of the sclerotesta (Section Stangerioides), this species is distinguished by the narrow leaflets and small stature, with a petiole that is usually not wholly spinescent, and leaves that are moderately keeled with leaflets distinctly twisted on the rachis. Pollen cones are also quite large.

Distribution and habitat: This species is known from the Nanpan and Qingshui valleys in south-western Guizhou province, eastern Yunnan and north-western Guangxi provinces. It is typical of low, scrubby forests on steep slopes on limestone bluffs or screes.

Conservation status: Walters et al. (1995) report extensive destruction of this species during the cultural revolution, regarding it as the most seriously threatened of all Chinese cycads. They also report that the Qian-Xu-Nan Prefecture Department of Forestry in Xing-yi has abandoned hope of in situ protection (in that prefecture), and are concentrating on ex situ conservation collections. More recent studies indicate however that this species is moderately abundant over a considerable area around the common borders of Guizhou, Guangxi and Yunnan provinces, and there is no immediate threat. It is known in populations exceeding 10,100 in places, and is also widespread on steep and almost inaccessable limestone mountains. It was listed by the 1997 IUCN Red List of Threatened Plants as category V, although considerable confusion is shown by the inclusion of C. szechuanensis as a synonym, and then the listing of the latter separately as category Ex (see also C taiwaniana). The current status is IUCN Red List category LR,nt.
Photo Ken Hill
Photo Ken Hill


Stems arborescent to acaulescent, to 1 m tall, 10-15 cm diam. at narrowest point; 5-20 leaves in crown.

Leaves deep green, semiglossy, 100-180 cm long, slightly keeled (opposing leaflets inserted at 130-170° on rachis), with 110-210 leaflets, with orange tomentum shedding as leaf expands; rachis consistently terminated by paired leaflets. Petiole 30-60 cm long (25-40% of total leaf), petiole glabrous, spinescent for 40-100% of length. Basal leaflets not gradually reducing to spines, 110-200 mm long.

Median leaflets simple, strongly discolorous, 160-370 mm long, 8-12 mm wide, inserted at 55-65° to rachis, decurrent for 4-5 mm, narrowed to 2.5-3 mm at base (to 30-40% of maximum width), 10-16 mm apart on rachis; median leaflets section slightly keeled; margins flat, or slightly recurved; apex acute, not spinescent; midrib raised above, flat below or raised below.

Cataphylls narrowly triangular, soft, pilose, 50-80 mm long, persistent.

Pollen cones fusiform, orange to brown (very pale), 20-40 cm long, 6-14 cm diam.; microsporophyll lamina soft, not dorsiventrally thickened, 30-40 mm long, 17-20 mm wide, fertile zone 27-36 mm long, sterile apex 3-5 mm long, level, apical spine absent.

Megasporophylls 10-20 cm long, yellow-tomentose or brown-tomentose; ovules 4-8, glabrous; lamina orbicular, 60-70 mm long, 60-80 mm wide, deeply pectinate, with 17-33 soft lateral spines 20-45 mm long, 2-4 mm wide, apical spine distinct from lateral spines, 25-45 mm long, 9-17 mm wide at base.

Seeds subglobose, 23-29 mm long, 22-28 mm wide; sarcotesta yellow, not pruinose, 1.5 mm thick; fibrous layer absent; sclerotesta smooth, or verrucose. Spongy endocarp absent.

The Cycad Pages

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Written and maintained by Ken Hill 1998-2010
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