32. Euclidium R. Brown in W. T. Aiton, Hortus Kew. 4: 74. 1812.
鸟头荠属 niao tou ji shu
Hierochontis Medikus, nom. rej.; Soria Adanson, nom. rej.
Herbs annual. Trichomes unicellular, eglandular, simple and stalked forked, in different sizes, some subsetose. Stems erect or ascending, simple or branched. Basal leaves petiolate, not rosulate, simple, entire, dentate, or rarely pinnatifid, often withered by flowering. Cauline leaves similar to basal, entire or dentate, reduced in size upward. Racemes ebracteate, elongated in fruit. Fruiting pedicels stout, thickened, erect, appressed to rachis. Sepals oblong, erect, base of lateral pair not saccate. Petals white, slightly longer than sepals; blade narrowly spatulate, apex emarginate; claw slightly differentiated from blade, shorter than sepals. Stamens 6, slightly tetradynamous; filaments not dilated at base; anthers ovate, apiculate at apex. Nectar glands 4, lateral, 1 on each side of lateral stamen; median glands absent. Ovules 2 per ovary, subapical. Fruit indehiscent, nutletlike silicles, ovoid, slightly 4-angled, sessile; valves thickened, woody, veinless, rough pubescent; replum strongly expanded laterally; septum complete, thickened; style to 1.8 mm, stout, subconical, curved, persistent; stigma capitate, 2-lobed, lobes not decurrent. Seeds wingless, oblong, plump; seed coat smooth, not mucilaginous when wetted; cotyledons accumbent or obliquely so.
One species: C and SW Asia, E Europe, naturalized elsewhere.