Stellaria obtusa |
Stellaria pallida |
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blunt-sepal starwort, obtuse starwort, Rocky Mountain chickweed, Rocky Mountain starwort |
lesser chickweed, pale starwort |
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Habit | Plants perennial, creeping, often matted but not forming cushions, rhizomatous. | Plants annual, usually yellowish green, with slender taproot. |
Stems | prostrate, branched, 4-sided, 3–23 cm, internodes equaling or longer than leaves, glabrous, rarely pilose. |
prostrate, much-branched, 4-sided, usually 10–20(–40) cm, glabrous, with single line of hairs along each internode. |
Leaves | sessile or short-petiolate; blade broadly ovate to elliptic, 0.2–1.2 cm × 0.9–7 mm, base round or cuneate, margins entire, apex acute, shiny, glabrous or ciliate near base. |
petiolate (proximal) or sessile (distal); blade ovate to elliptic, usually 0.3–1.5 cm × 1–7 mm, base round to cuneate, margins entire, apex shortly acuminate, glabrous or with few cilia on margins and abaxial midrib. |
Inflorescences | with flowers solitary, axillary; bracts absent. |
terminal, 3–35-flowered cymes; bracts lanceolate, 2–10 mm, herbaceous, margins entire. |
Pedicels | spreading, 3–12 mm, glabrous. |
spreading, sometimes deflexed at base in fruit, 1–10 mm, pubescent. |
Flowers | 1.5–2 mm diam.; sepals 4–5, veins obscure, midrib sometimes apparent, ± ovate, 1.5–3.5 mm, margins narrow, scarious, apex ± obtuse, glabrous; petals absent; stamens 10 or fewer; styles 3(–4), curled, shorter than 0.5 mm. |
2–3 mm diam.; sepals 4–5, veins obscure, midrib sometimes present, lanceolate, 3–4 mm, margins narrow, herbaceous, apex acute, pubescent; petals usually absent; stamens 1–3 or absent; anthers gray-violet; styles 3, ascending, becoming curled, 0.2–0.5 mm. |
Capsules | green to pale straw colored, translucent, globose to broadly ovoid, 2.3–3.5 mm, 1.9–2 times as long as sepals, apex obtuse, opening by 6 valves; carpophore absent. |
pale straw colored, ovoid, 2–4(–5) mm, equaling to slightly longer than sepals, apex obtuse, opening by 6 valves, outwardly curled at tip; carpophore absent. |
Seeds | grayish black, broadly elliptic, 0.5–0.7 mm diam., finely reticulate. |
pale yellowish brown, reniform to round, 0.5–0.9 mm diam., tuberculate; tubercles prominent, broader than tall, apex obtuse. |
2n | = 26, 52, ca. 65, ca. 78. |
= 22. |
Stellaria obtusa |
Stellaria pallida |
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Phenology | Flowering late spring–summer. | Flowering spring. |
Habitat | Moist areas in woods, shaded edges of creeks, talus slopes | Dunes, sandy waste places, rest areas on interstate highways |
Elevation | 300-3400 m (1000-11200 ft) | 0-1500 m (0-4900 ft) |
Distribution |
CA; CO; ID; MT; OR; UT; WA; WY; AB; BC
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AR; AZ; CA; CO; FL; IN; KS; KY; LA; MI; MO; NC; NE; OH; OK; PA; SC; TN; TX; VA; WA; WV; ON; Mexico; Europe [Introduced in North America]
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Discussion | Stellaria pallida is automatically self-pollinated and often cleistogamous. It usually can be distinguished from apetalous forms of S. media by its smaller size, yellowish green color, its small sepals and small, pale seeds. Also the base and tip of the sepals occasionally are dark-red pigmented. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 5, p. 110. | FNA vol. 5, p. 111. |
Parent taxa | Caryophyllaceae > subfam. Alsinoideae > Stellaria | Caryophyllaceae > subfam. Alsinoideae > Stellaria |
Sibling taxa | ||
Synonyms | Alsine obtusa, Alsine viridula, Alsine washingtoniana, S. viridula, S. washingtoniana | Alsine pallida, S. boraeana, S. media subsp. pallida |
Name authority | Engelmann: Bot. Gaz. 7: 5. (1882) | (Dumortier) Crépin: Man. Fl. Belgique ed. 2, 19. (1866) |
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