American Chickweed

Stellaria americana is remarkable for its tortuous fruiting pedicels, which push the opening capsule with its small number of large seeds into the substrate.

Plants perennial, forming loose, prostrate mats, from rhizomatous rootstocks. Stems spreading, branched, very leafy, 4-angled, 10-20 cm, short glandular-puberulent on internodes. Leaves sessile; blade ovate to ovate-lanceolate, widest at or above middle, 8-30 × 2-13 mm, base round to cuneate, margins not scarious, apex usually obtuse, viscid. Inflorescences terminal, 1-5-flowered, very leafy cymes; bracts foliaceous. Pedicels ca. 10 mm in flower, elongating, recurved, and tortuous in fruit, glandular-pubescent, pushing capsule into substrate. Flowers 5-10 mm; sepals 5, obscurely veined, ovate-obtuse, 3-5 mm, margins narrow, scarious, glandular-pubescent; petals 5, 4-6 mm; stamens 5; styles 3, ascending, equaling petals. Capsules green to straw colored, broadly ovoid to globose, 5-6 mm, apex obtuse, tardily dehiscent with 3 valves; carpophore absent. Seeds 3-6, rusty brown, ± ovate, ca. 2.5 mm diam., finely tuberculate.

Alta.; Mont.

Flowering late Jul-Aug.

Rocky slopes, talus; 1400-2800m.

Stellaria dichotoma Linnaeus var. americana Porter ex B. L. Robinson, Proc. Amer. Acad. Arts 29: 289. 1894; Alsine americana (Porter ex B. L. Robinson) Rydberg; Arenaria stephaniana (Willdenow ex Schlechtendal) Shinners var. americana (Porter ex B. L. Robinson) Shinners