《中国植物志》|| 七指蕨科 HELMINTHOSTACHYACEAE ||七指蕨属 Helminthostachys Kaulf. ||七指蕨 Helminthostachys zeylanica (L. ) Hook.

1．七指蕨（中国蕨类植物图谱，第一卷）图版I，7-8
Helminthostachys zeylanica (Linn. ) Hook. Gen. Fil. (1840) t. 47; Hook. et Bak. Syn. Fil. (1874) 447; Bedd. Ferns S. Ind. (1873) t. 67; Handb. Ferns Brit. Ind. (1883) 467, f. 292; Christ, Farnkr. d. Erde (1897) 365; Diels in Engl. u. Prantl, Nat, Pflanzenfam. I, iv (1899) 472; C. Chr. Ind. Fil. (1905) 344; Cop. in Philip. Journ. Sci. IV (1909) t. 14; Ching, Ic. Fil. Sinic. I (1930) t. 1; Tard. Blot et C. Chr. in Fl. Indo-Chine VII, ii (1939) 10, f. 1; H. Ito, Fil. Jap. Illustr. (1944) t. 512; Holt. Fl. Mal. II, Ferns Mal. (1954) 42, f. 2——Osmunda zeylanica Linn. Sp. Pl. II (1753) 1063——Botrychium Neylanicum Sw. in Schrad. Journ. (1801) 111——Ophiala zeylanica Desv. Prod. (1827) 195——Helminthostachys dulcis Kaulf. in Flora (1822) 103; Enum. Fil. (1824)28, t. 1. f. 1.
根状茎肉质，横走，粗达7毫米，有很多肉质的粗根，靠近顶部生出一或二枚叶，叶柄为绿色，草质，长20-40厘米，基部有两片长圆形淡棕色的托叶，长约7毫米，叶片由三裂的营养叶片和一枚直立的孢子囊穗组成，自柄端彼此分离，营养叶片几乎是三等分，每分由一枚顶生羽片（或小叶）和在它下面的1-2对侧生羽片（或小叶）组成，每分基部略具短柄，但各羽片无柄，基部往往狭而下延，全叶片长宽约12-25厘米，宽掌状，各羽片长约10-18厘米，宽约2－4厘米，向基部渐狭，向顶端为渐尖头，边缘为全缘或往往稍有不整齐的锯齿。叶薄草质，无毛，干后为绿色或褐绿色，中肋明显，上面凹陷，下面凸起，侧脉分离，密生，纤细，斜向上，1-2次分叉，达于叶边。孢子囊穗单生，通常高出不育叶，柄长6-8厘米，穗长达13厘米，直径5-7毫米，直立，孢子囊环生于囊托，形成细长圆柱形。
产于台湾、海南（五指山）和云南南部（西双版纳）。
本种是热带植物，生于湿润疏荫林下。广泛分布于印度支那、缅甸、印度北部、泰国、马来亚、锡兰、菲律宾、印度尼西亚达于澳洲等地。
在南洋各地，本种植物的嫩叶作蔬菜用，根作补剂。在自然界中，本种的叶片均指向天空成杯形，中央抽出一枚直立的孢子囊穗，甚为美观。

《Flora of China》|| Ophioglossaceae || Helminthostachys ||七指蕨 Helminthostachys zeylanica

1. Helminthostachys zeylanica (Linnaeus) Hooker, Gen. Fil. t. 47. 1840.

七指蕨 qi zhi jue

Osmunda zeylanica Linnaeus, Sp. Pl. 2: 1063. 1753; Botrychium zeylanicum (Linnaeus) Swartz; Helminthostachys dulcis Kaulfuss, nom. illeg. superfl.; Ophiala zeylanica (Linnaeus) Desvaux.

Rhizome 4-8 mm in diam. Fronds usually single at rhizome apex, 20-60 cm tall; stipe base sheath ca. 1 cm; common stipe fleshy, 10-55 cm, 2-8 mm in diam., glabrous; sterile lamina ternate with basal pinnae divided into 3 or 4 pinnules; pinnules lanceolate, 6-20 × 1.5-3 cm, base decurrent, margin irregularly toothed, apex acute or rounded. Spikelike sporophore arising at top of common stipe; stalk 4-10 cm, spike 4-20 cm, 5-12 mm in diam., branches divided 1 or 2 times, each consisting of stalk bearing a pseudowhorl of sporangia and 1-4 forked sterile apical appendages. 2n = 188.

Forests, edges of marshes; low elevations. Guangdong, Hainan, Taiwan, Yunnan [widespread: Cambodia, India, Japan, Laos, Philippines, Sri Lanka, Thailand, Vietnam; tropical Australia, W Pacific islands].

Helminthostachys zeylanica is a rare, endangered species in China because of over-collecting for use in traditional medicine and because of habitat change.