Description
Key Characters:
Growth Form:
Perennial herbs.
Stems:
Stems prostrate, sometimes rooting at the nodes, 1–5 dm long, moderately to densely pilose, the hairs multicellular.
Roots:
Leaves:
Leaves simple.
Opposite.
Blades oblanceolate to obovate or suborbicular, (0.8–)1.5–2(–3) cm long, 0.5–1.2 cm wide.
Surfaces sparsely pilose.
Margins entire.
Petioles 0.3–1.5 cm long, moderately pilose.
Stipules absent.
Flowers:
Flowers sessile in densely pubescent spikes.
Flowers bisexual (perfect), actinomorphic. Each flower subtended by a bract and 2 bracteoles. Bract 3–4 mm long, tipped with a spine ca. 0.5–0.7 mm long, bracteoles ca. 3 mm long, acuminate, bract and bracteoles densely pilose at least below.
Calyx of 5 sepals, unequal, the 2 abaxial ones 3.5–4.2 mm long, spine–tipped, the spine less than 1 mm long, other sepals spineless, the adaxial one ca. 3 mm long, the 2 inner ones 2–2.5 mm long, all sepals pilose, the adaxial one only at base.
Corolla (petals) absent.
Stamens 5, all fertile.
Ovary superior, 2–3(4)-carpellate, the carpels connate to form a compound, 1-celled ovary; ovule placentation basal, free-central, or rarely apical; style 1, often lobed.
Fruit:
Utricles 1–1.5 mm long; enclosed by the sepals.
Seeds 1 per fruit; the surface usually lustrous; endosperm essentially absent.
Ploidy:
2n = 96
Habitat:
Naturalized in dry areas; roadsides; lawns; and beach parks.
Elevation Range: