Cerastium texanum Britton
Family: Caryophyllaceae
Texas chickweed,  more...
[Cerastium sordidum B.L. Robins.,  more...]
Cerastium texanum image

Plants annual, with slender taproot and branched caudex. Stems erect, sparingly branched proximally, slender, 15-35 cm, sparsely glandular-pilose; small axillary tufts of leaves 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 ob-lanceolate, 7-30 mm, apex acute, pilose. Inflorescences very open and loose, 2-9(-25)-flowered cymes; bracts narrowly lanceolate, pilose. Pedicels straight, becoming sharply deflexed at base, slender, 5-20 mm, elongating in fruit, 1.5-4 times as long as sepals, glandular-pilose. 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. Seeds red-brown, 0.4-0.7 mm diam., tuberculate; tubercles ± pointed; testa not inflated. 2n = 36.

Flowering spring. Canyons, sandy washes, oak woodlands, mountain pine forests; 1200-2800 m; Ariz., N.Mex.; Mexico.

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.

Duration: Annual

Nativity: Native

Lifeform: Forb/Herb

General: Annual, 15-35 cm tall; stems erect, slender, sparingly branched towards the base, sparsely glandular-pilose; caudex branched; taproot slender.

Leaves: Basal and cauline, opposite, simple, the basal blades spatulate, 0.8-5.5 cm long, 3-16 mm wide, the cauline blades few (2-4 pairs), confined to the lower part of the stem, linear-lanceolate to narrowly oblanceolate, 0.7-3 cm long, surfaces pilose, apex acute, the basal ones sometimes obtuse; basal blades petiolate, cauline blades sessile.

Flowers: Inflorescence a loose, open cyme, mostly 3-21 flowered; bracts herbaceous, lanceolate, glandular-pubescent; pedicels ascending, strongly deflexed at the summit when in fruit, 5-20 (35) mm long, 1-3 times as long as the calyx in flower, as much as 5 times as long when in fruit; sepals ovate-lanceolate, 4-6 mm long, glandular- pubescent, apex broadly acute to obtuse; petals oblanceolate, 3-6 (8) mm long, somewhat shorter than to slightly surpassing the sepals, white, the apex 2-lobed; flowers March-October.

Fruits: Capsule, cylindric, straight, 5-12 mm long, 1.5-2 times as long as the calyx; teeth becoming outwardly coiled; seeds numerous, reddish brown.

Ecology: Oak woodlands, pine forests, partially shaded areas, moist habitats, canyons, washes; 1700-2600 m (5500-8500 ft); Apache, Cochise, Coconino, Gila, Graham, Maricopa, Pima, Santa Cruz, and Yavapai counties; southwestern U.S., Mexico.

Notes: na

Editor: Springer et al. 2008

Cerastium texanum image
Cerastium texanum image
Cerastium texanum image
Cerastium texanum image
Cerastium texanum image
Cerastium texanum image
Cerastium texanum image
Cerastium texanum image
Cerastium texanum image
© Smithsonian Institution, National Museum of Natural History, Department of Botany