Tridax procumbens |
Asteraceae tribe Heliantheae subtribe Galinsoginae |
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cadillo chisaca, coat buttons, tridax |
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Habit | Annuals, perennials, subshrubs, or shrubs, (2–)10–150[–300+] cm. | |||||||||||||
Leaves | petioles 1–10(–30) mm; blades 10–40(–120) × 5–20(–60) mm, often 3-lobed. |
mostly basal or mostly cauline; usually opposite (distal sometimes alternate); petiolate or sessile; blades (often 3- or 5-nerved) mostly deltate, elliptic, lanceolate, lance-ovate, 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 gland-dotted or stipitate-glandular. |
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Involucres | campanulate, cylindric, hemispheric, or ± obpyramidal. |
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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- or 3-lobed or -toothed). |
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Ray florets | 0, or (3–)6–21, pistillate, fertile; corollas yellow or whitish or pinkish [purplish]. |
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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. |
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Phyllaries | persistent or falling, 6–30+ in 2–5+ series, usually distinct, elliptic, lanceolate, lance-linear, lance-ovate, oblong, or ovate, subequal or unequal (outer longer or shorter). |
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Calyculi | 0. |
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Heads | radiate or discoid (sometimes ± disciform in Bebbia), borne singly or in loose to tight, corymbiform or cymiform arrays. |
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Cypselae | 2–2.5 mm; pappi 4–5(–7.5) mm. |
± compressed, often clavate, obconic, or ovoid, or obpyramidal and 3-, 4-, 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. |
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2n | = 36. |
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Tridax procumbens |
Asteraceae tribe Heliantheae subtribe Galinsoginae |
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Phenology | Flowering Jan–Dec. | |||||||||||||
Habitat | Disturbed sites | |||||||||||||
Elevation | 0–10 m (0–0 ft) | |||||||||||||
Distribution |
FL; TX; Mexico [Introduced in North America]
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Subtropical; tropical; and warm-temperate New World |
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Discussion | Tridax procumbens is listed as a noxious weed for United States and is listed as a pest or noxious weed for nine or more states. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 21, p. 180. | FNA vol. 21, p. 176. | ||||||||||||
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Galinsoginae > Tridax | Asteraceae > tribe Heliantheae | ||||||||||||
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Name authority | Linnaeus: Sp. Pl. 2: 900. (1753) | Bentham & Hooker f.: Gen. Pl. 2: 198. (1873) | ||||||||||||
Web links |