《中国植物志》|| 茜草科 RUBIACEAE ||真耳草组 Sect. Euoldenlandia K. Schum. ||白花蛇舌草 Hedyotis diffusa Willd.

57. 白花蛇舌草（潮州志）
Hedyotis diffusa Willd. Sp. Pl. 1: 566. 1797; Backer in Backer et Bakh. Fl. Java 2: 286. 1965; 海南植物志3: 307. 1974; 中国高等植物图鉴4: 224, 图5861, 1975; J. M. Chao in Li, Fl. Taiwan 4: 272. 1978; Hara et Gould in Hara et al. Enum. Flow. Pl. Nepal. 2: 202. 1979. ——H. herbacea Lour. Fl. Cochinch. 77. 1790 et op. cit. ed Willd. 98. 1793, non Linn. (1753).——Oldenlandia diffusa(Willd.) Roxb. Hort. Beng. 11. 1814 et Fl. Ind. ed. Carey 1: 423. 1824; Hook. f. Fl. Brit. Ind. 3: 65. 1880; Pitard in Lecomte, Fl. Gen. Indo-Chine 3: 145. 1923. ——O. herbacea Linn. var. uniflora Benth. Fl. Hongk. 151. 1861.
一年生无毛纤细披散草本，高20-50厘米；茎稍扁，从基部开始分枝。叶对生，无柄，膜质，线形，长1-3厘米，宽1-3毫米，顶端短尖，边缘干后常背卷，上面光滑，下面有时粗糙；中脉在上面下陷，侧脉不明显；托叶长1-2毫米，基部合生，顶部芒尖。花4数，单生或双生于叶腋；花梗略粗壮，长2-5毫米，罕无梗或偶有长达10毫米的花梗；萼管球形，长1.5毫米，萼檐裂片长圆状披针形，长1.5-2毫米，顶部渐尖，具缘毛；花冠白色，管形，长3.5-4毫米，冠管长1.5-2毫米，喉部无毛，花冠裂片卵状长圆形，长约2毫米，顶端钝；雄蕊生于冠管喉部，花丝长0.8-1毫米，花药突出，长圆形，与花丝等长或略长；花柱长2-3毫米，柱头2裂，裂片广展，有乳头状凸点。蒴果膜质，扁球形，直径2-2.5毫米，宿存萼檐裂片长1.5-2毫米，成熟时顶部室背开裂；种子每室约10粒，具棱，干后深褐色，有深而粗的窝孔。花期春季。
产于广东、香港、广西、海南、安徽、云南等省区；多见于水田、田埂和湿润的旷地。国外分布于热带亚洲，西至尼泊尔，日本亦产。
据《广西中药志》记载全草入药，内服治肿瘤、蛇咬伤、小儿疳积；外用主治泡疮、刀伤、跌打等症。

《云南植物志》|| 茜草科 Rubiaceae ||耳草属 Hedyotis Linn. ||白花蛇舌草 Hedyotis diffusa Willd.

20.白花蛇舌草（潮州志）图版7: 4—6
小叶锅巴草（峨山），牙灵俄（傣语）
Hedyotis diffusa Willd. (1797); 图鉴 (1975)*; Hara et Gould in Hara et al. (1979); 云南种子植物名录 (1984); 中国植物志 (1999).
Oldenlandia diffusa (Willd.) Roxb. (1814), (1820), (1832); Hook. f. (1880); Hand.-Mazz. (1937); 广州植物志 (1956).
一年生披散纤细无毛草本，高20—50厘米。叶对生，膜质，无柄，线形，长1—3厘米，宽1—3毫米，先端短尖，边缘干后常背卷，叶面光滑，背面有时粗糙，中脉在叶面下陷，在叶背面凸起，侧脉不明显；托叶长1—2毫米，基部合生，顶部芒尖。花4数，单生或双生于叶腋，无花梗或具短而粗的花梗，花梗长2—5毫米，稀长达10毫米；萼管球形，长1.5毫米，花萼裂片长圆状披针形，长1.5—2毫米，边缘具缘毛；花冠白色，管状，长3.5—4毫米，冠管长1.5—2毫米，冠管喉部无毛，花冠裂片卵状长圆形，长约2毫米；雄蕊着生于冠管喉部，花丝长0.8—1毫米，花药伸出，长圆形，长约1毫米；花柱长2—3毫米，柱头2裂，裂片广展，有乳头状凸点。蒴果膜质，扁球形，直径2—2.5毫米，宿存萼裂片长1.5—2毫米，成熟时顶部室背开裂；种子每室约10颗，具棱，干后深褐色，有窝孔。花果期5—10月。
产福贡、昆明、峨山、屏边、金平、景东、澜沧、勐腊、景洪、勐海、凤庆、保山；生于海拔950—1550米的草坡、溪边、田边或旷野潮湿地。广西、海南、香港、广东、湖南、江西、安徽、福建、台湾也有。分布于越南、老挝、泰国、柬埔寨、尼泊尔、印度、斯里兰卡、马来西亚、印度尼西亚、菲律宾、日本。
全草入药，清热、解毒、活血、利尿，可治癌症及炎症；外用可治泡疮、刀伤、跌打等症。

《Flora of China》|| Rubiaceae || Hedyotis ||白花蛇耳草 Hedyotis diffusa

25. Hedyotis diffusa Willdenow, Sp. Pl. 1: 566. 1798.

白花蛇耳草 bai hua she er cao

Hedyotis herbacea Loureiro (1790), not Linnaeus (1753); Oldenlandia diffusa (Willdenow) Roxburgh; O. herbacea (Linnaeus) Roxburgh var. uniflora Bentham.

Slender herbs, annual, ascending to procumbent, to 50 cm tall; stems slightly flattened to terete or young stems sometimes 4-angled, sparsely to densely puberulent, scaberulous, or glabrescent to glabrous, similarly glabrous or pubescent on angles and to sides. Leaves sessile or subsessile; blade drying membranous, linear, narrowly elliptic, or narrowly oblanceolate, 1-4 × 0.1-0.4 cm, adaxially glabrous and smooth or often scaberulous near margins, abaxially glabrous to scaberulous, base acute, margins usually revolute at least when dry, apex acute; secondary veins not visible; stipules fused to petiole bases, triangular to truncate, 0.5-1.5 mm, glabrescent, acute to aristate or with 1-3 bristles 0.2-1 mm. Inflorescences axillary, 1-flowered or fasciculate and 2-flowered, glabrous, pedunculate; peduncles or pedicels 4-20 mm; bracts none or stipuliform, to 1 mm. Flowers pedicellate, apparently homostylous. Calyx glabrous; hypanthium portion subglobose, 1-1.2 mm; limb lobed essentially to base; lobes narrowly triangular, 1-2 mm, ciliolate. Corolla white, tubular, outside glabrous; tube 1.5-2.5 mm, glabrous inside; lobes ovate-oblong, 1.2-2 mm. Anthers ca. 0.8 mm, exserted. Stigma ca. 1.2 mm, exserted. Fruit capsular, compressed globose to oblate, 2-3 × 2-3 mm, sometimes somewhat dicoccous, membranous, glabrous, loculicidally dehiscent on flat to beaked top, beak rounded, to 0.5 mm, with peduncles elongating rapidly and markedly as fruit mature, to 20 mm; seeds ca. 20, dark brown, angled, deeply thickly foveolate. Fl. and fr. May-Oct.

Paddy fields, ridges of farmlands, humid open fields; sea level to 900 m. Anhui, Fujian, Guangdong, Guangxi, Hainan, Taiwan, Yunnan, Zhejiang [Bangladesh, Bhutan, Indonesia, Japan, Malaysia, Nepal, Philippines, Sri Lanka, Thailand].

This species is very commonly collected in China. The taxonomy of this and related species is complicated, and different authors have drawn very different conclusions (e.g., Sivarajan & Biju, Taxon 39: 665-674. 1990; Dutta & Deb, Taxon. Rev. Hedyotis. 2004). In particular, Hedyotis brachypoda, H. corymbosa, and H. erecta are related and have been variously circumscribed. Here, these species are circumscribed generally, though not completely, following W. C. Ko (in FRPS 71(1): 72, 75. 1999) and Dutta and Deb.