Cerastium fontanum |
Cerastium velutinum |
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common chickweed, common mouse-ear chickweed, céraiste commun, mouse-ear chickweed |
large field mouse-ear chickweed |
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Habit | Plants perennial (rarely annual), tufted to mat-forming, often rhizomatous. | Plants perennial, usually clumped, taproot present, sometimes with short rhizomes. | ||||||||
Stems | flowering stems erect from decumbent base, branched proximally, 10–45 cm, softly pubescent, eglandular with straight hairs; nonflowering shoots, when present, produced proximally, decumbent, rooting at nodes, branched, 5–20 cm, often subglabrous with alternating lines of eglandular hairs; small axillary tufts of leaves usually absent. |
flowering shoots ascending, often decumbent at base, branched, (15–)25–35(–40) cm, softly pubescent to subglabrous, hairs spreading, straight, concentrated in longitudinal lines toward base, glandular and eglandular; nonflowering leafy shoots often present, straggling, 5–15 cm; small axillary tufts of leaves present. |
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Leaves | not marcescent; blade 10–25(–40) × 3–8(–12) mm, densely covered with patent to ascending, colorless, long, eglandular hairs; leaves of flowering shoots in distant pairs, sessile, blade elliptic to ovate-oblong, apex subacute; leaves of sterile shoots pseudopetiolate, often spatulate, blade oblanceolate, apex obtuse. |
sessile; cauline with largest at mid stem, smaller distally and proximally, blade narrowly oblong, linear-lanceolate to lanceolate or ovate, 20–45 × 3–11 mm, apex usually obtuse, softly ciliate-pubescent on both surfaces, more so on margins and abaxial midrib, rarely subglabrous, sometimes densely villose; proximal leaf blades often oblanceolate, apex ± obtuse. |
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Inflorescences | lax, 3–50-flowered cymes; bracts lanceolate, reduced, herbaceous, eglandular-pubescent, distal often with narrow, scarious margins. |
lax, 5–20-flowered cymes, pubescent, glandular, not viscid; bracts lanceolate, proximal foliaceous, distal smaller, with scarious margins, glandular-pubescent. |
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Pedicels | somewhat curved distally, 2–10(–20) mm, longer than sepals, densely pubescent with patent, eglandular, rarely glandular hairs. |
curved immediately below capsule, slender, 10–24 mm, ca. 2 times as long as sepals, pubescence spreading, glandular. |
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Flowers | sepals ovate-lanceolate, 5–7 mm, margins narrow, apex acute, scarious, pubescent with eglandular, rarely glandular, hairs; petals oblanceolate, 1–1.5 times as long as sepals, apex deeply 2-fid; stamens 10, occasionally 5; styles 5. |
sepals lanceolate-elliptic, 5–8 mm, margins narrow, apex acute, densely and softly glandular-pubescent; petals obovate, 10–15 mm, 2 times as long as sepals, apex deeply 2-fid; stamens 10; anthers 0.9–1.1 mm; styles 5. |
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Capsules | narrowly cylindric, curved, 9–17 mm, ca. 2 times sepals; teeth 10, erect, margins convolute. |
cylindric, slightly curved, slender, 10–14 × 3–4 mm, 2–2.3 times as long as sepals; teeth 10, erect, margins convolute. |
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Seeds | reddish brown, 0.4–1.2 mm, bluntly tuberculate; testa not inflated, tightly enclosing seed. |
brown, 0.8–1.2 mm diam., tuberculate; testa not inflated, tightly enclosing seed. |
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2n | = 122–152, usually 144. |
= 72. |
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Cerastium fontanum |
Cerastium velutinum |
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Distribution |
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NS; NT; ON; PE; QC; SK; YT; Europe [Introduced elsewhere]
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DC; DE; IA; IL; IN; KY; MA; MD; MI; MN; MO; NJ; NY; OH; PA; TN; VA; WV; ON
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Discussion | Subspecies 4 (2 in the flora). Cerastium fontanum is a highly variable and complex species. It often has been reported as C. vulgatum Linnaeus, an ambiguous name; see discussion under the genus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 2 (2 in the flora). Until recently Cerastium velutinum has been included in C. arvense as a variety or subspecies. However, morphological characters and chromosome number (diploid in the native forms of C. arvense, tetraploid in C. velutinum) distinguish the two taxa. They are not interfertile. Crosses between them can be produced with difficulty but they are completely sterile. None are known to occur naturally. An apparent hybrid between Cerastium velutinum and C. tometosum has been collected on the south shore of Lake Erie. It was completely sterile. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 5. | FNA vol. 5, p. 91. | ||||||||
Parent taxa | Caryophyllaceae > subfam. Alsinoideae > Cerastium | Caryophyllaceae > subfam. Alsinoideae > Cerastium | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Name authority | Baumgarten: Enum. Stirp. Transsilv. 1: 425. (1816) | Rafinesque: Med. Repos., hexade 2, 5: 359. (1808) | ||||||||
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