2.
Galinsoga quadriradiata
Ruiz & Pavón, Syst. Veg. Fl. Peruv. Chil. 1: 198. 1798.
Galinsoga bicolorata
H. St. John & D. White;
G. caracasana
(de Candolle) Schultz-Bipontinus;
G. ciliata
(Rafinesque) S. F. Blake
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.
2
n
= 32 [48, 64].
Flowering and fruiting summer—fall. Disturbed soils, fields, orchards, gardens, lawns, roadsides; 0—2500 m; introduced; Alta., B.C., Man., N.B., N.S., Ont., P.E.I., Que., Sask.; Ala., Ark., Colo., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Mich., Minn., Mo., Nebr., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., Wash., W.Va., Wis.; Mexico; West Indies; Central America; South America; introduced in Europe; Asia; Africa; Pacific Islands.
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.
