-- 作者： tenway0609 -- 發表時間： 2008/06/02 08:44pm 要很用功才看的懂@@!! 真希望有中文版~ Cycas multipinnata Trunk almost subterranean, to 40 × 20 cm above ground; bark brown-gray, scaly. Leaves 1(or 2), 3-pinnate, trullate in outline, flat, 3-7 m × 60-100 cm; petiole subterete, 1.5-2.5 m × 3-6 cm; spines 30-50 along each side, 3-6 cm apart, compressed conical, 3-5 mm; primary leaflets in 12-22 pairs, longitudinally inserted at 60-90° to primary rachis, lanceolate, slightly "V"-shaped in cross section at 100-130° to rachis; middle leaflets largest, 35-60 × 15-20 cm; basal and apical leaflets gradually shorter, 20-40 × 10-15 cm; secondary leaflets flabellate or obtriangular, dichotomously (2 or)3-5-forked, 20-22 × 5-15 cm, with petiolule 0.5-5 cm; segments (ultimate leaflets) obovate-linear, regular, 7-12 × 1-2 cm, papery, midvein slightly elevated on both surfaces, base decurrent, glabrous, margin entire or somewhat wavy, apex shortly acuminate to caudate. Pollen cones fusiform-cylindric, 15-23 × 4-6 cm; microsporophylls 1.2-2 cm × 8-10 mm, tomentose, apex acute. Megasporophylls 8-12 cm, brown tomentose, glabrescent; stalk ca. 4 cm; sterile blade triangular-ovate, 4-7 × 3-6.5 cm, deeply divided into 25-35 subulate lobes 1-3.5 cm; ovules 3-5 on each side of stalk. Seeds 6-10, greenish to yellowish, obovoid, slightly compressed, 2.5-3.2 × 2.3-2.8 cm; sclerotesta finely verrucose, apex mucronate. Pollination Apr-May, seed maturity Oct-Nov. * Red soil over granite or limestone in somewhat shaded monsoon forests along valleys; 200-1000 m. SE Yunnan (Gejiu Shi, Hekou Yaozu Zizhixian, Mengzi Xian, Pingbian Miaozu Zizhixian) This and Cycas debaoeusis, with their 3-pinnate leaves, are the most distinct of all extant cycads. Cycas multipinnata is also one of the most endangered cycads in China, mainly as a result of over collection by commercial dealers and habitat damage as forests are opened up for farmland. If conservation measures are not taken immediately, the species will most likely become extinct in the wild within the next ten years. Cycas debaoeusis Trunk almost subterranean, to 40(-70) × 25(-40) cm above ground, sometimes clumped; bark brown-gray, scaly toward apex of trunk, subsmooth toward base. Leaves (3-)5-11(-15), 3-pinnate, ovate in outline, ± openly "V"-shaped in cross section at 110-150° between leaflets, 1.3-2.7 × 0.5-1.5 m; petiole obovate-orbicular in cross section, 0.6-1.3 m × 1.5-3 cm, tomentose when young, later glabrescent except at base, spiny except at base; spines 20-55 along adaxial part of each side, 1-4.5 cm apart, conical, 3-4 mm; primary leaflets in 6-14 pairs, 3-12 cm apart, middle leaflets subopposite, longest, 40-70 × 20-27 cm, "V"-shaped in cross section at 70-90° between secondary leaflets, basal and apical leaflets alternate, gradually smaller toward base and apex of leaf blade, 17-50 × 10-23 cm; secondary leaflets in 3-5 pairs, ovate to obtriangular, dichotomously 2- or 3-forked, 12-25 × 4-15 cm, with petiolule 0.5-2 cm; segments (ultimate leaflets) 3-5, green and shiny above, light green below, linear, 10-22(-28) × 0.8-1.5 cm, thickly papery, glabrous, midvein raised on both surfaces, base decurrent, margin flat or somewhat undulate, apex long attenuate or long acuminate. Cataphylls triangular, 6-8 × 2.5-3 cm, densely brown tomentose, apex acuminate, somewhat soft. Pollen cones ovoid and brown tomentose initially, fusiform-cylindric and glabrescent at maturity, 13-25 × 4-9 cm; microsporophylls narrowly cuneate, 3-3.5 × 1.2-1.6 cm, apical sterile part semiorbicular, slightly revolute, apex broadly rounded with short, upcurved mucro. Megasporophylls 30-50, laxly grouped, 15-20 cm, yellow-brown tomentose, forming an oblate group 18-25 cm in diam.; stalk 9-12 cm; sterile blade green, subcordate or subflabellate, 6-9 × 5-10 cm, glabrescent, deeply divided into 39-51 filiform lobes 3-6 cm, terminal lobe 4-5 cm; ovules 2 or 3 on each side of stalk, glabrous. Seeds 3 or 4, green to yellowish and brown, subglobose or obovoid-globose, slightly compressed, 3-3.5 × 2.5-3 cm, apex mucronate; sclerotesta finely verrucose. Pollination Mar-Apr, seed maturity Nov. * Thickets and sparse forests of small trees on dry, sunny, open slopes of limestone hills; 700-1000 m. NW Guangxi (Debao Xian) This recently described species is most similar to Cycas multipinnata in its 3-pinnate leaf structure, but differs in its more numerous and much shorter leaves, with segments long attenuate or long acuminate at the apex; its megasporophylls, with subcordate or subflabellate, wider sterile blades divided into 39-51 filiform lobes; and its dry and sunny habitat. Unfortunately, this cycad is one of the most endangered in China, restricted to a very small area (ca. 20 ha) in a village, and will become extinct in the wild within the next ten years unless conservation measures are implemented. -- 作者： campbell -- 發表時間： 2008/06/02 11:16pm 請見雲南植物志, 其中有中文描述 這兩種在Flora of China 07:4中並未收錄, 線上亦有部份資料 http://baike.baidu.com/view/185875.html http://baike.baidu.com/view/1281983.html -- 作者： tenway0609 -- 發表時間： 2008/06/03 00:03am Cycas multipinnata----2.8~1.8億年前~ Cycas debaoeusis----3.8億年前~ 會不會有進化的淵源呢?遠古生物真是非常有趣^^~ 非洲系的鐵樹歷史不知是否也如此悠久∼ -- 作者： campbell -- 發表時間： 2008/06/03 10:49am 據說Encephalartos是比較後期發生的. 雖然存在爭議 但應該肯定比Cycads要晚近多了