Herbs annual, short-caulescent, subscapose, distinctly pubescent, from fibrous roots; sap clear. Stems leafy at and near base, erect, branching from base. Leaves opposite, sessile; blade broadly linear, unlobed. Inflorescences axillary or terminal, 1-flowered; bracts absent; bud nodding. Flowers: sepals 3, with overlapping, loosely connivent flaps; petals 6, occasionally more on robust specimens; stamens 12 or more, usually in several series; filaments dilated distally; pistil 3-carpellate; ovary 1-locular; stigmas 3. Capsules erect, 3-valved, dehiscing from apex. Seeds many, aril absent. x = 7.
|[Greek hesperos, evening or western, and mecon, poppy]|