Japanese nipplewort

Lapsana apogonoides Maximowicz, Bull. Acad. Imp. Sci. Saint-Pétersbourg 18: 288. 1873

Stems slender, weak, flattened. Leaves: basal blades 40–100 × 10–25 mm, dentate, apices obtuse. Phyllaries broadly lanceolate, thin, scarcely keeled, 4–5 mm, stellately spreading in fruit. Corollas 6–10 mm. Cypselae straight, 4–5 mm. 2n = 16.

Flowering May–Jun. Cultivated fields, disturbed areas, low boggy areas; 10–100 m; introduced. Oreg.; Asia (China, Japan, Korea).

Lapsanastrum apogonoides is distinguished by its prostrate habit, weak stems, lyrate leaves, and 5 phyllaries spreading in fruit.