台湾苏铁 guang dong su tie

Cycas diannanensis Z. T. Guan & G. D. Tao; C. fairylakea D. Y. Wang; C. pectinata Griffith subsp. manhaoensis C. Chen & P. Yun; C. revoluta Thunberg var. taiwaniana (Carruthers) Schuster.

Trunk cylindric, to 3.5 m × 35 cm; bark dark brown or gray-brown, scaly. Leaves 60-90, 1-pinnate, 1.5-3 m × 40-60 cm; petiole obovate in cross section, 40-120 cm, with 30-60 spines along each side of basal part, glabrous; leaf blade oblong, flat, orange-brown tomentose when young; leaflets in 70-150 pairs, longitudinally inserted at 55-75° to rachis, often falcate, 18-35 cm × 11-14 mm, leathery, glabrous abaxially, midvein raised on both surfaces only when fresh, slightly raised or flat abaxially when dry, base decurrent, margin flat, apex attenuate, pungent. Cataphylls triangular-lanceolate, ca. 8 × 2.5 cm, densely brown tomentose, apex with long, hard point. Pollen cones ovoid or ellipsoid-cylindric, 30-45 × 8-10 cm; microsporophylls narrowly cuneate, 2-3 cm × 5-8 mm; apex obtuse-rounded, with very short, upcurved mucro. Megasporophylls more than 30, tightly grouped, 15-22 cm, pale brown tomentose; stalk 8-12 cm; sterile blade rhombic-ovate, 7-12 × 6-7 cm, margin glabresent and pectinate, with (11-)23-47 lobes 2-3.5 cm, terminal lobe ± flattened, 2-3.5 cm × 5-10 mm, margin usually irregularly serrulate, apex acute; ovules 2 or 3 on each side of distal part of stalk, glabrous. Seeds 2(-4), pale yellowish, globose, or broadly obovoid, slightly compressed, 2.8-3.3 × 2.5-3 cm; sclerotesta finely verrucose. Pollination Apr-May, seed maturity Sep-Nov.

Sunny, grassy places or sparse, mixed forests, often disturbed places, long cultivated in S China but now only sporadically distributed in the wild; 400-1100 m. Guangdong, E Guangxi, SW Hunan, SE Yunnan [?Vietnam]