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common chickweed, common mouse-ear chickweed, céraiste commun, mouse-ear chickweed

céraiste à trois styles, mountain chickweed, starwort mouse-ear chickweed

Habit Plants perennial (rarely annual), tufted to mat-forming, often rhizomatous. Plants perennial, mat-forming, rhizomatous.
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.

creeping, much-branched, rooting, glabrous except for line of small hairs down each internode; flowering shoots decumbent or ascending, 5–10 cm; nonflowering shoots prostrate, 5–15 cm; small axillary tufts of leaves usually absent.

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, tending to be marcescent, somewhat succulent;

blade elliptic-oblong or linear-lanceolate, 2–12 × 1–3 mm, apex obtuse, rarely acute, glabrous, sometimes ciliate at base.

Inflorescences

lax, 3–50-flowered cymes;

bracts lanceolate, reduced, herbaceous, eglandular-pubescent, distal often with narrow, scarious margins.

lax, 1–3-flowered terminal cymes;

bracts lanceolate, 2–5 mm, glabrous or ciliate.

Pedicels

somewhat curved distally, 2–10(–20) mm, longer than sepals, densely pubescent with patent, eglandular, rarely glandular hairs.

becoming curved, slender, 5–35 mm, equaling or exceeding sepals, glandular-puberulent.

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 narrowly lanceolate, 4–5 mm, margins narrow, midrib present, apex obtuse, glandular-pubescent towards base;

petals 5–8 mm, 1–1.5 times as long as sepals, apex deeply 2-fid;

stamens 10;

styles 3(–6).

Capsules

narrowly cylindric, curved, 9–17 mm, ca. 2 times sepals;

teeth 10, erect, margins convolute.

ovoid-conic, oblong after dehiscence, straight, 7–10 mm, 1.5–2 times as long as sepals;

teeth 6(–12), erect to spreading, margins convolute.

Seeds

reddish brown, 0.4–1.2 mm, bluntly tuberculate;

testa not inflated, tightly enclosing seed.

brown, 0.5 mm diam., shallowly rugose;

testa not inflated.

2n

= 122–152, usually 144.

= 38.

Cerastium fontanum

Cerastium cerastoides

Phenology Flowering summer.
Habitat Wet, arctic areas, alpine rills, alpine and arctic snowbeds
Elevation 0-800 m (0-2600 ft)
Distribution
from FNA
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]
[WildflowerSearch map]
[BONAP county map]
from FNA
NL; NU; QC; Greenland; Europe; amphi-Atlantic
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.)

Cerastium cerastoides is an unusual member of the genus because it normally has only three styles and a straight, six-toothed capsule, rather than a curved capsule as in most of the other species. The blunt sepals help to distinguish this species from C. arvense subsp. strictum, with which it is most likely to be confused. The epithet of this species is often misspelled “cerastioides.”

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Inflorescences never glandular; petals 1.3-1.5 times as long as sepals; capsules 11-17 mm; seeds 0.9-1.2 mm
subsp. fontanum
1. Inflorescences occasionally viscid-glandular; petals equaling sepals; capsules 9-13 mm; seeds 0.4-0.9 mm
subsp. vulgare
Source FNA vol. 5. FNA vol. 5, p. 84.
Parent taxa Caryophyllaceae > subfam. Alsinoideae > Cerastium Caryophyllaceae > subfam. Alsinoideae > Cerastium
Sibling taxa
C. aleuticum, C. alpinum, C. arcticum, C. arvense, C. axillare, C. beeringianum, C. bialynickii, C. brachypetalum, C. brachypodum, C. cerastoides, C. dichotomum, C. diffusum, C. dubium, C. fastigiatum, C. fischerianum, C. glomeratum, C. maximum, C. nutans, C. pumilum, C. regelii, C. semidecandrum, C. terrae-novae, C. texanum, C. tomentosum, C. velutinum, C. viride
C. aleuticum, C. alpinum, C. arcticum, C. arvense, C. axillare, C. beeringianum, C. bialynickii, C. brachypetalum, C. brachypodum, C. dichotomum, C. diffusum, C. dubium, C. fastigiatum, C. fischerianum, C. fontanum, C. glomeratum, C. maximum, C. nutans, C. pumilum, C. regelii, C. semidecandrum, C. terrae-novae, C. texanum, C. tomentosum, C. velutinum, C. viride
Subordinate taxa
C. fontanum subsp. fontanum, C. fontanum subsp. vulgare
Synonyms Stellaria cerastoides, Arenaria trigyna, C. lapponicum, C. trigynum, Dichodon cerastoides, Provencheria cerastoides
Name authority Baumgarten: Enum. Stirp. Transsilv. 1: 425. (1816) (Linnaeus) Britton: Mem. Torrey Bot. Club 5: 150. (1894)
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