Stellaria cuspidata

Willdenow ex Schlechtendal

Ges. Naturf. Freunde Berlin Mag. Neuesten Entdeck. Gesammten Naturk. 7: 196. 1816.

Common names: Mexican chickweed
Synonyms: Alsine cuspidata (Willdenow ex Schlechtendal) Wooton & Standley
Treatment appears in FNA Volume 5. Treatment on page 104. Mentioned on page 97.

Plants annual; taproot slender. Stems decumbent, much-branched, 4-sided, 15–70 cm, softly glandular-pubescent. Leaves petiolate (proximal) or sessile (distal), flaccid; blade ovate to deltate, 1–4.5 cm × 6–28 mm, base cordate, truncate, or rarely abruptly rounded, margins entire, apex acuminate, glabrous, rarely ciliate on margins. Inflorescences terminal, (3–)5–35-flowered cymes; bracts sessile, foliaceous, lanceolate to ovate, 3–30 mm, distally reduced. Pedicels ascending to spreading, sometimes deflexed in fruit, slender, 5–20(–30) mm, softly glandular. Flowers 3–8 mm diam.; sepals 5, with prominent midrib, lanceolate to ovate-lanceolate, 4–5 mm, to 8 mm in fruit, margins narrow, scarious, apex acuminate, blunt, pubescent on midrib, ± ciliate on margins; petals 4–5, 2–8 mm, shorter than to 2 times as long as sepals, blade apex deeply emarginate with 2 narrow lobes; stamens 3–8; styles 3, ascending, outwardly curved, 1.5–3 mm. Capsules green, transparent, ovoid, 4–6 mm, ± equaling sepals, apex obtuse, opening by 6 valves, recurved at tip; carpophore absent. Seeds reddish brown, round, 1–1.2 mm diam., covered with prominent, stalked glands. 2n = 26, 52.

Distribution

V5 213-distribution-map.gif

Fla., La., N.Mex., Tex., Mexico, Bermuda, South America.

Discussion

Subspecies 2 (2 in the flora).

Petal length, along with sepal and capsule size and shape, vary in the two subspecies. Although they appear to be distinct in the southern United States, in Mexico where their ranges overlap, plants of uncertain identification are frequently encountered.

Selected References

None.

Key

1 Petals 5-8 mm, 1.5-2 times as long as sepals; sepals narrowly lanceolate, apex acuminate, 7-8 mm in fruit; montane Stellaria cuspidata subsp. cuspidata
1 Petals 2-4 mm, equaling or shorter than sepals; sepals ovate-lanceolate, 4-5 mm in fruit; lowlands Stellaria cuspidata subsp. prostrata