Cerastium glomeratum Thuill. , sticky mouse–ear chickweed. Annual, taprooted, typically 1—several–stemmed at base, ascending to spreading, in range (5—)10—25 cm tall; shoots ± pilose with erect multicellular hairs and some capitate glandular hairs (mostly in flowering canopy).

Stems

Stems cylindric, 1 mm diameter, green becoming flesh–colored or deep purplish red, internodes in range < 40 mm long, the shortest at plant base.

Leaves

Leaves opposite decussate, simple, sessile with pair connected by 2 low ledges across node, without stipules; blade oblanceolate or obovate to elliptic or ovate, in range 12—27 × 3.5—12 mm, dull, broadly to narrowly tapered at base, entire and ciliate on margins, acute to rounded or obtuse at tip, sometimes sheathing stem for 0.5—1 mm, appearing faintly parallel–veined at base with midrib raised on lower surface, pilose.

Inflorescence

Inflorescence dichasial cyme, terminal or occasionally axillary, open or compact when young, 20—140 × 30—110 mm, equally 2–forked at each node, several—many–flowered, bracteate; bracts subtending each fork 2, leaflike but reduced upward (never scarious); bractlets subtending pedicels absent; pedicel typically 1—2.5 mm long, pilose and capitate–glandular.

Flower

Flower bisexual, radial, 8—10 mm across; hypanthium inconspicuous; sepals 5, lanceolate, at anthesis 3.1—3.5 × 0.8—1.1 mm increasing to 4—5 mm long in fruit, green and colorless–scarious on exposed margins, acute at tip, with fine venation, glandular–hairy, pilose at tip with hairs > (sometimes with a purple line or dot approaching tip); petals 5, 2–lobed oblanceolate, ± 4 mm long > length of sepals, white; stamens 10, free; filaments erect, slender, 1.3—1.5 mm long, whitish translucent; anthers basifixed, minutely dithecal, < 0.2 mm long, pale yellow, longitudinally dehiscent; pollen pale yellow; pistil 1; ovary superior, ovoid to oblong, ca. 1.2 × 0.8 mm, glabrous, light green, 1–chambered with ca. 25 ovules attached to central post; styles 5, ascending, 0.7 mm long, colorless, pubescent above midpoint (= stigmatic region).

Fruit

Fruit capsule, dehiscent by 10 teethlike valves at tip, 15—25–seeded, cylindric and mostly straight, 6.5—7.5 × 1.2—1.9 mm, glabrous, whitish translucent but greenish at base; teeth acuminate, with outwardly folding margins.

Seed

Seed triangular–ovoid compressed side–to–side, ca. 0.5 × 0.4 × 0.2 mm, light brown to pale reddish brown, glabrous, with short, hard projections or minutely warty.

A. C. Gibson & B. A. Prigge