Asteraceae (tribe Heliantheae) subtribe Galinsoginae
Gen. Pl. 2: 198. 1873.
Annuals, perennials, subshrubs, or shrubs, (2–) 10–150 [–300+] cm. Leaves mostly basal or mostly cauline; usually opposite (distal sometimes alternate); petiolate or sessile; blades (often 3-nerved or 5-nerved) mostly deltate, elliptic, lanceolate, lanceovate, linear, ovate, or rhombic, sometimes pinnately or palmately lobed, ultimate margins entire or ± toothed, faces glabrate, hispid, hispidulous, pilose, puberulent, scabrellous, scabrous, strigillose, or strigose, often glanddotted or stipitate-glandular. Heads radiate or discoid (sometimes ± disciform in Bebbia), borne singly or in loose to tight, corymbiform or cymiform arrays. Calyculi 0. Involucres campanulate, cylindric, hemispheric, or ± obpyramidal. Phyllaries persistent or falling, 6–30+ in 2–5+ series, usually distinct, elliptic, lanceolate, lance-linear, lanceovate, oblong, or ovate, subequal or unequal (outer longer or shorter). Receptacles flat, convex, or conic, paleate (paleae persistent or falling with cypselae, mostly oblong to lanceolate or linear, flat to conduplicate, herbaceous or scarious, often 2-lobed or 3-lobed or toothed). Ray-florets 0, or (3–) 6–21, pistillate, fertile; corollas yellow or whitish or pinkish [purplish]. Disc-florets 5–150+, bisexual, fertile (peripheral sometimes pistillate in Bebbia); corollas yellow to orange, or whitish, pinkish, or purplish, tubes shorter than throats, lobes 5, deltate to lance-deltate or lanceolate (± equal [outer larger, e.g., some plants of Tridax]); anther thecae pale or slightly darkened; stigmatic papillae in 2 lines. Cypselae ± compressed, often clavate, obconic, or ovoid, or obpyramidal and 3-angled, 4-angled, or 5-angled, glabrous or sparsely to densely piloso-sericeous, sericeous, strigillose, or strigose; pappi 0, or persistent, of 1–10+ subulate to acerose scales, or 5–20 ± spatulate, entire to erose, fimbriate, or laciniate, sometimes aristate, scales in 1 series, or 15–25+ [–40], plumose, setiform scales (or flattened bristles) in 1 series.
Subtropical, tropical, and warm-temperate New World
Genera 15, species 103 (4 genera, 8 species in the flora).
All genera of Galinsoginae are centered in tropical and subtropical to warm-temperate North America and South America; relatively few extend into cool-temperate areas; fewer still are adventive in the Old World.
|1||Phyllaries 10–20 in ± 2 series (outer 4 broadly lanceolate, foliaceous, notably larger than inner)||Tetragonotheca|
|1||Phyllaries 6–30+ in 2–5 series (subequal or unequal, outer smaller than inner).||> 2|
|2||Annuals (ray cypselae often each shed together with subtending phyllary and 2 adjacent paleae)||Galinsoga|
|2||Perennials, subshrubs, or shrubs (cypselae shed separate from paleae)||> 3|
|3||Subshrubs or shrubs, 50–140 cm (often forming dense, rounded masses)||Bebbia|
|3||Perennials, 10–40 cm (stems procumbent to ascending)||Tridax|