形態特徵
一、二年生草本,高30-60厘米,全株被多細胞紫色腺毛。根紡錘形或圓錐形。莖疏叢生或單生,黃色。葉片橢圓形或卵狀橢圓形,長1-4厘米,寬 (0.5-) 1-2毫米,頂端急尖,基部楔形,兩面被稀疏腺毛,下面中脈微凸起,莖下部葉具短柄,上部葉無柄。二歧聚傘花序具數花;苞片卵狀披針形,長3-5毫米,被腺毛;花梗長1-2 (-3) 厘米,密被腺毛;萼片5,披針形,長5-6毫米,頂端鈍尖,邊緣狹膜質,外面密被腺毛;花瓣5,白色,倒卵形或倒卵狀匙形,長7-8毫米,頂端縊狀裂;雄蕊10,微露花萼外,花葯淡黃色;子房卵圓形,花柱2,線形。蒴果卵形,與宿存萼等長或稍短,4裂;種子2-3粒,扁圓形,直徑約2毫米,表面具細紋。花期7-8月,果期8-9月。產地生境
產雲南西北部(維西、中甸、碧江、貢山、德欽)、西藏東南部(聶拉木、亞東、米林、錯那、察隅)。生於海拔(2 500-) 3 200-4 500米的山坡草地、高山草甸及冷杉林緣灌叢中。印度、錫金、不丹、尼泊爾也有。模式標本采自錫金。參考文獻
柔軟無心菜(西藏植物志)Arenaria debilis Hook. f., Fl. Brit. Ind. 1: 242. 184; W. W. Smith in Rec. Bot. Surv. Ind. 4: 180. 1911 et l. c. 4: 357. 1913; K. Biswas, Pl. Darj. Sikk. Himal. 1: l6l. 1967; Hara et al., Enum. Flow. Pl. Napal 2: 51. 1979; 西藏植物志1: 682. 1983, p. p. excl. syn.——A. glandulosa (Benth. ex G. Don) Williams in Bull. Herb. Boiss. 5: 603. 1895 et in Journ. Linn. Soc. Bot. 33: 431. 1898, non Jacq. (1798) ; 中國高等植物圖鑑補編1: 304. 1982. ——Odontostemma glandulosa Benth. (in Wall.Cat. 22. n. 645. 1892, nom. nud.) ex G. Don, Gen. Syst. 1: 4. 49. 1831. ——Arenaria benthamii Edgew. in Hook. f. Fl. Brit. Ind. 1: 242. 1874; W. W. Smith in Rec. Bot. Surv. Ind. 4: 356. 1913, non Fenzl (1840). ——A. yunnanensis Franch. f. angustifolic Williams in Journ. Linn. Soc. Bot. 33: 430. 1898 et l. c. 38: 402. 1909. ——A. blinkworthii McNeill in Not. Bot. Gard. Edinb. 24 (2): 128. 1962. ——A. sikkimensis Majumdar in Journ. Ind. Bot. Soc. 44: 141. 1965. ——Lepyrodiclis debilis (Hook. f.) Ohba in Ohashi, Fl. East. Himal. 3: 31. 1975. ——Arenaria aureocaulis C. Y. Wu ex L. H. Zhou in Icon. Corm. Sin. Suppl. 1: 304. 1982, in clavi, nom. nud.et Act. Biol. Plat. Sin. 6: 32. tab. 5. fig. 6-8. 1987 et l. c. 6: 31: fig. 1一5.1987, fide C. Y. Wu in herb. ——-A. stellarioides C. Y. Wu ex L. H. Zhou in Icon.Corm. Sin. Suppl. 1: 304. 1982, in clavi.