Umbrella Starwort

Plants perennial, forming small clumps or mats, rarely long-straggling, from slender rhizomes. Stems erect, branched at base, 4-angled, 5-20 cm (rarely to 40 cm when long and straggling), gla-brous. Leaves spatulate-petiolate (proximal) or sessile (distal), bases clasping, connate around stem, ciliate; blade elliptic to lanceolate, 3-9 cm × 1-3 mm, somewhat succulent, base round to cuneate, margins entire, apex acute, glabrous. Inflorescences terminal, (1-)2-ca. 21-flowered, subumbellate, often with 1 or 2 axillary flowers below; bracts lanceolate, 1-7 mm, distal ones entire, scarious, proximal ones usually herbaceous. Pedicels sharply deflexed at base, often curved distally in fruit, 7-20 mm, glabrous. Flowers ca. 2 mm diam.; sepals 5, 3-veined, lanceolate, 2.5-3 mm, margins narrow, scarious, apex obtuse, glabrous; petals absent; stamens 5; styles 3, ascending, curled, ca. 0.25 mm. Capsules straw colored, conic, 3-4.5 mm, exceeding sepals, apex obtuse, opening by 6 valves; carpophore absent. Seeds brownish, round, 0.5-0.7 mm diam., shallowly rugose. 2n = 26.

Herbs perennial, glabrous. Stem solitary, 5--15 cm tall, branched. Leaves elliptic, 1.5--2 cm × 4--5 mm, both surfaces glabrous, base cuneate, slightly clasping, apex obtuse or acute. Flowers 3--10, in cymose umbel; bracts 3--5, ovate, nearly membranous. Pedicel filiform, 0.5--2 cm, slightly longer in fruit. Sepals 5, green, lanceolate, 2--3 mm, margin membranous, apex acuminate. Petals absent. Stamens 10, shorter than sepals. Ovary cylindric-ovoid; styles 3, linear, short. Capsule subequaling persistent sepals, 6-valved. Seeds reniform, slightly compressed, rugulose, without protuberances. Fl. Jun--Jul, fr. Jul--Aug. 2n = 26.

Alta., B.C., N.W.T., Yukon; Alaska, Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, Wash., Wyo.; Asia.

Gansu, Hebei, Qinghai, Shaanxi, Shanxi, Sichuan, Xinjiang, Xizang [Kazakhstan, Russia; North America].

Flowering summer.

Moist meadows, rocky summits, gravelly stream- and roadsides; 1000-2800m.

Montane grasslands, forests, steppes; 1600--3800(--5000) m.

Alsine baicalensis Coville; Stellaria gonomischa B. Boivin; S. weberi B. Boivin

Stellaria wutaica Handel-Mazzetti.

Stellaria irrigua is a species of flowering plant in the family Caryophyllaceae known by the common names umbrella starwort and umbellate starwort. It is native to western North America from Alaska and north-western Canada to the south-western United States, as well as parts of Asia, including Siberia. It grows in subalpine and alpine climates in mountain forests and riverbanks. It is a rhizomatous perennial herb producing a slender prostrate stem up to about 20 centimeters long, sometimes forming clumps or mats. The stem is lined with pairs of oval leaves each up to about 2 centimeters long. The inflorescence is an umbel-shaped array of several flowers each on an arching or erect pedicels. The flower has five pointed green sepals each no more than 3 millimeters long. There are occasionally tiny white petals within the calyx of sepals, but these are generally absent.