Cerastium texanum |
Cerastium dubium |
|
---|---|---|
Chihuahuan mouse-ear chickweed, Texas chickweed, Texas mouse-ear chickweed |
anomalous mouse-ear chickweed, doubtful chickweed, three-style chickweed |
|
Habit | Plants annual, with slender taproot and branched caudex. | Plants annual, taprooted. |
Stems | erect, sparingly branched proximally, slender, 15–35 cm, sparsely glandular-pilose; small axillary tufts of leaves absent. |
erect, many-branched from base, 10–40 cm, minutely viscid-glandular; small axillary tufts of leaves usually absent. |
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, distal sessile, proximal spatulate; blade linear or linear- lanceolate to linear-oblong, 10–30 × 1–4 mm, apex obtuse to subacute, glabrous or sparsely and minutely viscid-glandular. |
Inflorescences | very open and loose, 2–9(–25)-flowered cymes; bracts narrowly lanceolate, pilose. |
lax, 3–21(–30)-flowered cymes; bracts narrowly lanceolate, glandular-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. |
erect, slender, 2–15 mm, 0.5–3 times as long as sepals, glandular-puberulent Flowers: sepals ovate-lanceolate, 5–6 mm, margins narrow, apex acute to obtuse, minutely viscid-glandular; petals oblanceolate, 5–8 mm, 1.5 times as long as sepals, apex 2-fid; stamens 10; styles 3(–4). |
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. |
|
Capsules | cylindric, straight, 5–12 mm, 1.5–2 times as long as sepals; teeth 10, becoming outwardly coiled. |
oblong-ovoid, straight, 8–11 mm, ca. 2 times as long as sepals; teeth 6, occasionally 8, erect to spreading, margins convolute. |
Seeds | red-brown, 0.4–0.7 mm diam., tuberculate; tubercles ± pointed; testa not inflated. |
pale brown, ovate, 0.6 mm diam., tuberculate; testa not inflated. |
2n | = 36. |
= 36, 38. |
Cerastium texanum |
Cerastium dubium |
|
Phenology | Flowering spring. | Flowering spring. |
Habitat | Canyons, sandy washes, oak woodlands, mountain pine forests | Alien weed of cultivated land |
Elevation | 1200-2800 m (3900-9200 ft) | 200-800 m (700-2600 ft) |
Distribution |
AZ; NM; Mexico
|
AR; ID; IL; IN; KS; KY; MS; OH; OR; TN; VA; WA; s Europe; Asia [Introduced in North America]
|
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.) |
First collected in North America in 1966 in Washington, Cerastium dubium has now been gathered from many widely scattered sites, and appears to be spreading rapidly. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 5, p. 90. | FNA vol. 5, p. 85. |
Parent taxa | Caryophyllaceae > subfam. Alsinoideae > Cerastium | Caryophyllaceae > subfam. Alsinoideae > Cerastium |
Sibling taxa | ||
Synonyms | C. longepedunculatum var. sordidum, C. sordidum, Stellaria montana | Stellaria dubia, C. anomalum, Dichodon viscidum |
Name authority | Britton: Bull. Torrey Bot. Club 15: 97. (1888) | (Bastard) Guépin: Fl. Maine et Loire ed. 2, 1: 267. (1838) |
Web links |