Description

Key Characters:

Growth Form: Annual or perhaps sometimes biennial herbs.

Stems: Stems erect or rarely decumbent, 3.5–15 dm long, unbranched or with a few side branches, strigillose, especially below, and sparsely to densely villous and glandular pubescent.

Roots:

Leaves: Leaves simple. Alternate. Basal leaves narrowly elliptic to oblanceolate; cauline leaves very narrowly elliptic to lanceolate, basal leaves 10–15 cm long, 0.8–1.3 cm wide; cauline leaves 2–10 cm long, 0.6–1.2 cm wide. Margins of basal leaves flat or slightly undulate, margins serrate; cauline leaves flat or slightly undulate, margins serrate. Stipules absent.

Flowers: Flowers in the upper leaf axils, 1 to several opening each day per stem near sunset. Flowers bisexual (perfect), actinomorphic, 4-merous, in the leaf axils, opening near sunset or near sunrise. Sepals with distinct tips 1–3 mm long, valvate. Petals yellow, often with a red spot at the base, broadly obovate, 1.5–2.5(–3.5) cm long. Stamens 8, in two series; anthers versatile, the sporogenous tissue in each locule undivided, dithecal, opening by longitudinal slits. Pollen ca. 50% fertile. Ovary inferior, as many cells and carpels as sepals; ovules anatropous; style 1; stigma deeply 4-lobed, the lobes linear, surrounded by anthers at anthesis.

Fruit: Capsules conspicuously enlarged at apex; 3–4 cm long. Seeds in 2 rows per cell; ellipsoid; 1.3–1.8 mm long; with a short beak.

Ploidy: Self-compatible; usually autogamous; permanent translocation heterozygote; (2n: 14; ring of 14 chromosomes at meiotic metaphase I)

Habitat: Open sites; especially along roadsides.

Elevation Range: 1,200–2,740 m.