5. Lathyrus japonicus Willdenow, Sp. Pl. 3: 1092. 1802.
海滨山黧豆 hai bin shan li dou
Pisum maritimum Linnaeus, Sp. Pl. 2: 727. 1753; Lathyrus aleuticus (Greene ex T. G. White) Pobedimova; L. japonicus var. aleuticus (Greene ex T. G. White) Fernald; L. japonicus subsp. maritimus (Linnaeus) P. W. Ball; L. japonicus var. maritimus (Linnaeus) Kartesz & Gandhi; L. japonicus f. pubescens (Hartman) H. Ohashi & Tateishi; L. japonicus subsp. pubescens (Hartman) Korobkov; L. japonicus var. pubescens (Hartman) Karlsson; L. maritimus Bigelow (1824); L. maritimus (Linnaeus) Fries (1835); L. maritimus var. aleuticus Greene ex T. G. White; L. maritimus f. pubescens (Hartman) Saelán; L. maritimus subsp. pubescens (Hartman) C. Regel; L. maritimus var. pubescens (Hartman) X. Y. Zhu; L. maritimus var. velutinus Fries; P. maritimum var. pubescens Hartman.
Herbs perennial, 15-50 cm tall. Stem stoloniferous, creeping, wingless. Leaves with branched or simple tendril; stipules sagittate, 10-30 mm, glabrous; leaflets 3-5-paired, long elliptic or obovate, 25-33 × 11-18 mm, glabrous, with reticulate veins visible on both surfaces. Raceme shorter than leaf, 2-5-flowered. Calyx campanulate, 9-10(-12) mm, glabrous; teeth unequal, longest tooth 5-6 mm. Corolla purple, ca. 21 mm; standard orbicular, with claw; wings narrowly obovate, occasionally white. Ovary linear, glabrous or rarely hairy. Legume brown or purple-brown, compressed, ca. 5 cm, glabrous or puberulent. Seeds subglobose. Fl. May-Jul, fr. Jul-Aug.
Seashores. Hebei, Jiangsu, Liaoning, Shandong, Zhejiang [widely distributed on coasts of temperate Asia, Europe, North America, and South America (Chile)].
Plants glabrous or slightly hairy have been called Lathyrus japonicus f. japonicus, whereas plants obviously hairy have been called L. japonicus f. pubescens. The two forms are sympatrically distributed in China and elsewhere. Although widely recognized, they appear to intrograde, so they are not formally recognized in this account. Plants with white wings and keels have been described as L. japonicus f. albiflorus Miyabe & Tatewaki (Trans. Sapporo Nat. Hist. Soc. 14: 185. 1936).
