1. Cycadaceae (苏铁科)
2. Cycas (苏铁属)
3. Cycas szechuanensis (四川苏铁)

Cycas guizhouensis K. M. Lan & R. F. Zou; C. multiovula D. Y. Wang.

Trunk to 2.9(-5) m × 40(-50) cm; bark dark gray, scaly. Leaves 60-90, 1-pinnate, 1-2.5(-3) m × 35-50 cm; petiole subrhombic in cross section, 40-70 cm, with 25-50 spines along each side; leaf blade oblong, flat, pale brown villous when young; leaflets in 60-120 pairs, longitudinally inserted at ca. 50° to rachis, straight or slightly falcate, 15-35 × 0-1.3 cm, thick, leathery, glabrous, midvein strongly raised on both surfaces, base decurrent, margin flat or slightly recurved, apex acuminate. Cataphylls triangular, 4-5 × 1.5-2.2 cm, brown tomentose, apex with long, soft point. Pollen cones fusiform-cylindric, ca. 25 × 6 cm; microsporophylls cuneate, 2-3 × 0.8-1.2 cm. Megasporophylls more than 30, tightly grouped, 14-23 cm, densely yellowish brown tomentose; stalk 5-14 cm; sterile blade broadly ovate, obovate, or suborbicular, 6-11 × 5-9 cm, margin glabrescent and pectinate, with 17-27 subulate lobes 2-6 cm, terminal lobe subulate to flattened, a little longer than lateral lobes; ovules (2 or)3 or 4(or 5) on each side of stalk, orange, glabrous. Seeds pale yellow when fresh, pale brown when dry, subglobose or obovoid, slightly compressed, 2.5-3 × 2.3-2.8 cm, apex mucronate; sclerotesta smooth. Pollination Apr-Jun, seed maturity Oct-Nov.

Thickets and sparse forests along hot and dry valleys of the Nanpan Jiang; 400-1300 m. NW Guangxi, SW Guizhou, E Yunnan; cultivated in Guizhou, Sichuan, and Yunnan [Vietnam]

Described from sterile plants introduced to Sichuan from the Napan Jiang valley. As defined here, Cycas szechuanensis is a very wide ranging species, close to C. hainanensis, but differs in its smaller seeds. Recently, several wild populations and material in cultivation have been segregated as distinct species. However, more studies are necessary before it can be determined whether or not these entities appropriately represent the range of variability found within and between populations, and whether or not variation within vegetatively propagated material in cultivation merely represents extreme forms selected for their ornamental value.