Galinsoga quadriradiata Ruiz & Pav.

Tetraploids of Galinsoga quadriradiata are native to Mexico. Higher polyploids are found in South America and differ from the tetraploids by their coarsely crenate-serrate leaves, cylindro-campanulate involucres, and usually reddish purple limbs of ray corollas that extend at right angles to involucres.

Plants 8–62 cm. Leaf blades 20–60 × 15–45 mm. Peduncles 5–20 mm. Involucres hemispheric to campanulate, 3–6 mm diam. Phyllaries falling. Paleae: outer falling, broadly elliptic to obovate, 2–3 mm; inner falling, linear to lanceolate, 2–3 mm, entire or 2- or 3-lobed, lobes to ¹/3 total lengths, blunt. Ray florets (4–)5(–8); corollas usually white, sometimes pink, laminae 0.9–2.5 × 0.9–2 mm. Disc florets 15–35. Cypselae: rays 1.5–2 mm; discs 1.3–1.8 mm; pappi: rays of 6–15 fimbriate scales 0.5–1 mm; discs 0, or of usually 14–20, rarely 1–5, white, lanceolate to oblanceolate, fimbriate, sometimes aristate, scales 0.2–1.7 mm. 2n = 32 [48, 64].

A cosmopolitan weed, native of Mexico.

1400-1700 m

Galinsoga bicolorata H. St. John & D. White; G. caracasana (de Candolle) Schultz-Bipontinus; G. ciliata (Rafinesque) S. F. Blake