American starwort

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

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.

Flowering late Jul-Aug. Rocky slopes, talus; 1400-2800 m; Alta.; Mont.

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