Cerastium texanum |
Cerastium tomentosum |
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Chihuahuan mouse-ear chickweed, Texas chickweed, Texas mouse-ear chickweed |
céraiste tomenteux, dusty miller, snow-in-summer, snow-in-summer chickweed, tomentose chickweed |
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Habit | Plants annual, with slender taproot and branched caudex. | Plants perennial, mat-forming, rhizomatous. |
Stems | erect, sparingly branched proximally, slender, 15–35 cm, sparsely glandular-pilose; small axillary tufts of leaves absent. |
flowering stems ascending, branched, 15–40 cm; nonflowering stems prostrate proximally, rooting readily, pubescence dense, white-tomentose, eglandular; small axillary tufts of leaves often present. |
Leaves | not marcescent; proximal blades broadly spatulate-petiolate, 8–55 × 3–16 mm, apex acute or obtuse, sometimes short-acuminate, softly pilose; cauline few, sessile, blade linear-lanceolate to narrowly oblanceolate, 7–30 mm, apex acute, pilose. |
not marcescent, sessile; blade linear to linear-lanceolate or linear-oblong, 10–60 × 2–8 mm, apex ± obtuse, pubescence dense, whitish-tomentose, eglandular on both surfaces. |
Inflorescences | very open and loose, 2–9(–25)-flowered cymes; bracts narrowly lanceolate, pilose. |
lax, 3–13-flowered cymes; bracts lanceolate, margins scarious, pubescent. |
Pedicels | straight, becoming sharply deflexed at base, slender, 5–20 mm, elongating in fruit, 1.5–4 times as long as sepals, glandular-pilose. |
ascending, straight, 10–40 mm, 2–7 times as long as sepals, white-tomentose. |
Flowers | sepals green, turning pale orange-brown in fruit, lanceolate to ovate, 3–6 mm, margins narrow, apex acute, with short, glandular pubescence; petals oblanceolate, 5–8 mm, 1.5–2 times as long as sepals, apex 2-fid; stamens 5; styles 5. |
12–20 mm diam.; sepals narrowly lanceolate-elliptic, 5–7 mm, margins narrow, often scarious, apex acute, white-tomentose; petals obtriangular, 10–18 mm, 2–2.5 times as long as sepals, apex 2-fid; stamens 10; styles 5. |
Capsules | cylindric, straight, 5–12 mm, 1.5–2 times as long as sepals; teeth 10, becoming outwardly coiled. |
cylindric, slightly curved, 10–15 mm, 1.5–2 times as long as sepals; teeth 10, erect, margins convolute. |
Seeds | red-brown, 0.4–0.7 mm diam., tuberculate; tubercles ± pointed; testa not inflated. |
brown, ca. 1.5 mm, round tubercles on margins, faces shallowly rugose; testa not inflated. |
2n | = 36. |
= 72. |
Cerastium texanum |
Cerastium tomentosum |
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Phenology | Flowering spring. | Flowering spring. |
Habitat | Canyons, sandy washes, oak woodlands, mountain pine forests | A commonly grown rock-garden and wall plant, often escaping onto roadsides, riverbanks, old fields |
Elevation | 1200-2800 m (3900-9200 ft) | 0-400 m (0-1300 ft) |
Distribution |
AZ; NM; Mexico
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ME; MI; MT; NC; NE; NY; OH; OR; PA; WA; WI; WY; BC; MB; NB; NF; NS; ON; PE; QC; se Europe [Introduced in North America]
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Discussion | Cerastium texanum is exceptionally variable in flower and capsule size. The extent to which this variation is due to environmental conditions or is genic in origin is not known. The broad, spatulate basal leaves and the straight, cylindric capsule with its outwardly coiled (revolute) teeth distinguish this species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cerastium tomentosum hybridizes readily with the introduced C. arvense subsp. arvense (J. K. Morton 1973). North American reports of Cerastium biebersteinii de Candolle all appear to be referable to C. tomentosum. The two species are very similar, but C. biebersteinii has flat capsule teeth and is diploid (2n = 36); see M. K. Khalaf and C. A. Stace (2001). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 90. | FNA vol. 5, p. 91. |
Parent taxa | Caryophyllaceae > subfam. Alsinoideae > Cerastium | Caryophyllaceae > subfam. Alsinoideae > Cerastium |
Sibling taxa | ||
Synonyms | C. longepedunculatum var. sordidum, C. sordidum, Stellaria montana | |
Name authority | Britton: Bull. Torrey Bot. Club 15: 97. (1888) | Linnaeus: Sp. Pl. 1: 440. (1753) |
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