Arenaria serpyllifolia L.

Arenaria species are annual or perennial herbs, usually caespitose, somewhat cushionlike, stem erect or prostrate, branched dichotomously. Leaves simple, opposite, rarely somewhat whorled, ovate-lanceolate, orbicular, linear lanceolate, elliptic-oblong to subulate, margin entire, apex acute to acuminate, glabrous or pubescent, petiole sessile to subsessile, exstipulate. Inflorescence solitary or many, in axillary or terminal, dichasial cymes. Flowers bisexual, actinomorphic, sepals 4-5, free, margin scarious, apex obtuse or rarely emarginate, petals 4-5, free, pink, white or purple, longer than the sepals, margin entire or lacerate, rarely absent. Stamens 2-10, usually in 2 series, filaments free, filiform, those opposite to sepals are glandular and thickened at the base, anthers 2-locular, dorsifixed, dehiscing longitudinally disk hypogynous. Ovary superior, unilocular, ovules many, free central placentation, styles 2-3 or 4, filiform. Fruit capsule, obovoid-globose, 2-6 valved, rarely exceeding the persistent sepals. Seeds few to many, subobovoid to reniform, compressed, surface smooth.

Arenaria species flowers are complete, bisexual, i.e., with functional male (androecium) and female (gynoecium), including stamens, carpels and ovary; rarely unisexual. Pollination is entomophilous i.e., by insects, or cleistogamy i.e., by self or allogamy i.e., by cross pollination. Flowering/Fruiting: March-August/September-October.

Seeds may be dispersed by autochory i.e., self dispersal, anemochory i.e., wind dispersal, zoochory i.e., dispersal by birds or animals.

Annual herbs, about 10-30 cm tall, laxly caespitose, stem erect or decumbent, slender, branched dichotomously, pubescent with white recurved hairs, roots robust, slender and long. Leaves simple, opposite, dense, lanceolate to lanceolate-ovate, about 5-11 x 3-6 mm across, base clasping, margin entire or sparsely ciliate, apex acute, glabrous or sparsely ciliate both above and beneath, membranous, fleshy, midrib impressed above and prominent beneath, lateral veins absent on both sides, petiole subsessile or sessile, exstipulate. 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--SepInflorescence in axillary or terminal cymes. Flowers bisexual, actinomorphic, about 5-7 mm across, pedicel slender, erect, glandular pubescent, about 1 cm long, bracts lanceolate-ovate, herbaceous, margins membranous, apex acute, densely villous, about 3-6 mm long, sepals 5, free, lanceolate-ovate, tri-penta veined, base broad, margin membranous, apex acute, villous outside, about 3-4 mm long, petals 5, free, white, linear obovate, half as long as the sepals, margin entire, apex obtuse, about 1.5 x 0.8 mm across. Stamens 10, usually in 2 series, filaments free, filiform, shorter than sepals, those opposite to sepals are glandular and thickened at the base, anthers 2-locular, dorsifixed, creamish. Ovary superior, unilocular, ovoid, ovules many, free central placentation, styles 3, filiform. Fruit capsule, obovoid-globose, 6 valved, rarely exceeding the persistent sepals. Seeds subobovoid to reniform, compressed, pale brown, tuberculate with papillae.

Arenaria species are susceptible to various insect pests, powdery mildews, root knot by nematodes and moulds.

Subtropical to temperate places, altitude 1000-3200 m.

Not evaluated (IUCN).

Used in folk medicine.