1. Arenaria serpyllifolia Linnaeus, Sp. Pl. 1: 423. 1753.
无心菜 wu xin cai
Arenaria leptoclados Gussone; A. petiolata Hayata.
Herbs annual or biennial. Principal roots slender, with numerous smaller branches. Stems caespitose, erect or diffuse, 10--30 cm, densely white villous. Leaves sessile; leaf blade ovate, 4--12 × 3--7 mm, both surfaces glabrous or sparsely villous, 3-veined abaxially, base attenuate, margin ciliate, apex acute; proximal cauline leaves larger, distal ones smaller. Cymes many flowered; bracts ovate, 3--7 mm, herbaceous, usually densely villous. Pedicel slender, ca. 1 cm, densely villous or glandular pubescent. Sepals 5, lanceolate, 3--4 mm, villous abaxially, veins 3, impressed, margin membranous, apex acute. Petals 5, white, obovate, 1/3--1/2 as long as sepals, apex obtuse. Stamens 10, shorter than sepals. Ovary ovoid. Styles 3, linear. Capsule ovoid, equaling persistent sepals. Seeds pale brown, reniform, small, tuberculate with raised papillae. Fl. Jun--Aug, fr. Aug--Sep.
Mountain grassland slopes, sandy or stony barrens, fields, gardens; 600--4000 m. Widespread in China [N Africa, Asia, Australia, Europe, North America].
This species is used medicinally.