Description from Flora of China
Cycas brevipinnata Hung T. Chang & al.; C. longisporophylla F. N. Wei; C. septemsperma Hung T. Chang & al.; C. sexseminifera F. N. Wei; C. spiniformis J. Y. Liang; Epicycas miquelii (Warburg) de Laubenfels.
Trunk generally subterranean, often ellipsoid or abruptly tapered apically, sometimes to 60 × 20 cm above ground; bark white-gray, nearly smooth toward base of trunk. Leaves 25-40, 1-pinnate, 50-100 × 15-22 cm; petiole subterete, 10-20 cm, with 0-8 spines along each side of apical part; leaf blade oblong, flat; leaflets in 60-100 pairs, longitudinally inserted at ca. 90° to rachis, often overlapping, straight, 13-18 × 1.4-1.8 cm, thick, leathery, sparsely red-brown tomentose abaxially when young, later becoming dark green and glabrous, midvein nearly flat adaxially, raised abaxially, base usually truncate, decurrent, sometimes contracted, margin flat or only slightly revolute, apex mucronate, pungent at maturity. Cataphylls triangular, 3-4 × 1-1.3 cm, brown tomentose, apex soft. Pollen cones ovoid-fusiform, 20-30 × 6-8 cm; microsporophylls broadly cuneate, 1.5-3 × 1.2-1.5 cm, apical, sterile part subrhombic, thickened, densely pale brown tomentose, margin inconspicuously toothed, apex with short, upcurved mucro. Megasporophylls more than 30, tightly grouped, 8-14 cm, tawny tomentose when young, later glabresent; stalk 4.5-7.5 cm; sterile blade rhombic-ovate, 3.5-5.5 × 3-5 cm, margin pectinate, with 17-31 subulate lobes 1-2.5 cm, terminal lobe subulate, 3-4 cm; ovules 2 or 3 on each side of stalk, glabrous. Seeds 2-4, yellowish when fresh, brown when dry, obovoid or subglobose, 2-2.8 × 1.8-2.5 cm, apex mucronate; sclerotesta smooth. Pollination Mar-Apr, seed maturity Aug-Oct.
There are taxonomic problems with the species delimitation in the various populations of Cycas miquelii. The authors have chosen to recognize only two closely related species, C. ferruginea and C. mi-quelii, from among the many described because ample material was available and the characters separating them have no intermediate states. Cycas miquelii has dark green, leathery, glabrous leaflets that are truncate basally and mucronate and pungent apically, whereas C. fer-ruginea has light green, papery, adaxially pubescent leaflets that are attenuate basally and acute to acuminate and not pungent apically. Moreover, although their general distribution patterns are the same, there is no sympatry within individual populations. However, a more meaningful evaluation cannot be made until more material has been studied from more populations throughout the range. Chinese plants of C. miquelii have been misidentified as C. siamensis Miquel by some authors.
Semishaded, rocky crevices in broad-leaved forests in limestone mountains, often on N-facing slopes; 200-500 m. W Guangxi [N Vietnam]