Description

Key Characters:

Growth Form: Hemiparasitic annual herbs 1–8 dm tall.

Stems: Stems erect, unbranched or occasionally sparingly branched usually above the middle, villous and glandular pubescent to hirsute.

Roots:

Leaves: Leaves simple. Alternate. Blades lanceolate to oblanceolate or linear–elliptic, 1–6 cm long, 0.3–1.5 cm wide. Apex acute to broadly acute. Base attenuate. Surfaces puberulent and also sparsely hirstellous, especially along the veins; blades often early deciduous. Margins entire. Conspicuously 3-veined from the base. Sessile. Stipules absent.

Flowers: Flowers in dense spikes, these elongating so that older flowers are widely spaced; bracts gradually differing from the leaves, becoming shorter, broader, more incised, and colored toward apex, leaf-like, narrowly lanceolate to oblong, lower ones green, upper ones tipped with red, orange, or occasionally yellow. Flowers bisexual (perfect). Calyx cylindrical, 10–12 mm long, tomentose and usually glandular puberulent. Corolla greenish, strongly bilabiate, cylindrical, elongate and narrow, upper lip hooded and beak-like, ca. 10 mm long, usually slightly shorter than calyx, the hood puberulent, lower lip minute, ca. 1 mm long, lobes connate from base to apex and enclosing the anthers, lower lip overlapping upper lip in bud, 3-lobed. Stamens 4, in 2 pairs; anther sacs unequally placed, the outer one attached medially, the smaller one attached by its apex. Ovary superior, 2-carpellate, with as many cells; ovule placentation axile; styles solitary, terminal; stigma 2-lobed, capitate.

Fruit: Capsules globose–obovoid; 5–6 mm long; rupturing the calyces as they expand; base oblique. Seeds slightly irregular; usually cuneate; 0.7–1 mm long; seed coat loose and conspicuously reticulate; endosperm oily.

Ploidy: 2n = 24

Habitat: Disturbed areas such as along roadsides and as a pioneer on lava flows.

Elevation Range: 60–2,100 m.