铁刀木Cassia siamea Lam.

别名：Siamese cassia;

科名：豆科 Leguminosae

属名：决明属 Cassia

《中国植物志》第39卷138页
  21.铁刀木 黑心树（云南）图版47: 4-5
  Cassia siamea Lam. Encycl. 1: 648. 1785; DC. Prodr. 2: 499. 1825; Baker in ook. f. Fl. Brit. Ind. 2: 264. 1878; Gagnep. in Lecomte, Fl. Gen. Indo-Chine 2: 167. 1913; 中国主要植物图说——豆科67, 图66, 1955; 陈焕镛等, 海南植物志2: 233. 1965;中国高等植物图鉴2: 341, 图2411. 1972.
  乔木，高约10米左右；树皮灰色，近光滑，稍纵裂；嫩枝有棱条，疏被短柔毛。叶长20-30厘米；叶轴与叶柄无腺体，被微柔毛；小叶对生，6-10对，革质，长圆形或长圆状椭圆形，长3-6.5厘米，宽1.5-2.5厘米，顶端圆钝，常微凹，有短尖头，基部圆形，上面光滑无毛，下面粉白色，边全缘；小叶柄长2-3毫米；托叶线形，早落。总状花序生于枝条顶端的叶腋，并排成伞房花序状；苞片线形，长5-6毫米；萼片近圆形，不等大，外生的较小，内生的较大，外被细毛；花瓣黄色，阔倒卵形，长12-14毫米，具短柄；雄蕊10枚，其中7枚发育，3枚退化，花药顶孔开裂；子房无柄，被白色柔毛。荚果扁平，长15-30厘米，宽1-1.5厘米，边缘加厚，被柔毛，熟时带紫褐色；种子10-20颗。花期10-11月；果期12月-翌年1月。
  除云南有野生外，南方各省区均有栽培。印度、缅甸、泰国有分布。
  本种在我国栽培历史悠久，木材坚硬致密，耐水湿，不受虫蚝，为上等家具原料。老树材黑色，纹理甚美，可为乐器装饰。因其生长迅速，萌芽力强，枝干易燃，火力旺，在云南大量栽培作薪炭林，采用头状作业砍伐，砍后二年树高达3-4米，一般每四年轮伐一次。

《Flora of China》 Vol. 10 (2010)
Senna siamea  (Lamarck) H. S. Irwin & Barneby Mem. New York Bot. Gard. 35: 98. 1982.
铁刀木   tie dao mu
Cassia siamea Lamarck, Encycl. 1: 648. 1785.
Trees, 10-15 m tall. Bark gray, subsmooth; young branches ribbed, sparsely puberulent. Leaves 20-30 cm; stip-ules caducous, linear, tiny; rachis and petiole without glands, puberulent; leaflets 6-10(-15) pairs, oblong or ovate-oblong, 3-7 × 1.5-2.5 cm, leathery, abaxially finely pubescent, adaxially smooth and glabrous, base rounded, apex obtusely rounded, often emarginate, mucronate. Racemes in axils of apical leaves, often several forming a large terminal panicle on a robust pe-duncle 5-7 cm; bracts linear, 5-6 mm. Sepals suborbicular, unequal in size, outer smaller, inner larger, ca. 9 mm, outside hairy. Petals yellow, broadly obovate, 1.2-1.5 cm, shortly clawed. Stamens 10, among them 7 fertile, anthers opening by apical pores, 2 with filaments ca. 10 mm and anthers 6-7 mm, 4 or 5 with filaments 2-3 mm and anthers 5-6 mm, staminodes ca. 3 mm. Ovary sessile, densely white pubescent. Legume flat-tened, 15-30 × 1-1.5 cm, suture thick, riblike, pubescent, pur-plish brown when mature. Seeds 10-30, light brown, ovoid, 2-2.5 × 5-6 mm. 2n = 28.
Cultivated in S China [native to Myanmar and Thailand, and probably also to Cambodia, Laos, and Vietnam; widely cultivated in the tropics].
This tree is planted as an ornamental in parks and gardens and is used as a wayside tree. The hard, durable wood is used for furniture.This tree is planted as an ornamental in parks and gardens and is used as a wayside tree. The hard, durable wood is used for furniture.