Volume 2 > Part 2 > Year 1972 > Page 189 > Cycadaceae > Cycas

3. Cycas siamensis Miq.wfo-0000631666

emend. Schuster; Miq., Bot. Ztg 21: 334. 1863; Kurz, Fl. Burm. 2: 503. 1877; Dyer in Hook.f., Fl. Br. Ind. 5: 657. 1890; Léandri in Fl. Gén. I.-C. 5: 1088. 1931; Schuster inPflanzenr. 99: 80. 1932, p.p.; Raizada & Sahni, Indian Forest Rec. n.s. Bot. 5: 96. 1960; Smitin., Nat. Hist. Bull. Siam. Soc. 24: 173. 1971. Figs. 13a, 14b.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Small rosette shrub, often stemless but at times with a trunk up to 150 cm high, base abruptly swollen, trunk cylindric, smooth. Leaves 60–90 cm long, rusty villous while young, stiff, spreading. Leaflets about 70 pairs 7.5–20.5 cm long, 6 mm wide, linear, mucronate-acuminate; midrib prominent on both surfaces. Petiole about 30 cm long, thorny. Leaf bases brown villous. Male cone oblong about 30 cm long. Microsporophylls 17 mm long with a slender terminal point as long as the deltoid clavate limb. Macrosporophylls 10–10.5 cm long, at first densely tawny tomentose, then nearly glabrous; sterile part ovate-rhomboid, 2–2.5cm diameter, margin deeply pectinate, lacerate, with spinous teeth 2.5–5 cm long. Ovules 1 on each side of the stalk at the base of the sterile part. Seed ovoid-oblong, smooth, about 4 cm long.

Thailand : NORTHERN: Lampang, Phrae, Tak; NORTH-EASTERN: Phetchabun, Sakon Nakhon; EASTERN: Chaiyaphum, Nakhon Ratchasima; SOUTH-WESTERN: Kanchanaburi (type), Suphan Buri, Prachuap Khiri Khan.

Distribution : Burma, Laos, S Vietnam, Yunnan.

Ecology : The plant is common on lateritic soil in the dry deciduous dipterocarp forests, 20–400 m alt.

Vernacular : Maphrao tao (มะพร้าวเต่า), phraotao (พร้าวเต่า)(Northern); prong (ปรง)(Northeastern); phong (ผง), talapat rusi (ตาลปัตรฤาษี)(Southwestern).