Tagetes |
|||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
marigold |
|||||||||||||
Habit | Annuals, perennials, subshrubs, or shrubs [perennials], mostly 10–80(–200) cm. | ||||||||||||
Stems | erect, branched distally or ± throughout. |
||||||||||||
Leaves | cauline; mostly opposite (distal sometimes alternate); petiolate or sessile; blades mostly lanceolate to oblanceolate overall, usually 1–3-pinnately lobed or -pinnatisect, ultimate margins toothed or entire, faces glabrous or hairy (oil-glands scattered and/or submarginal). |
||||||||||||
Involucres | narrowly cylindric or fusiform to turbinate or broadly campanulate, 1–12+ mm diam. |
||||||||||||
Receptacles | convex to conic, smooth or finely pitted, epaleate. |
||||||||||||
Ray florets | 0 or 1–8(–13+) (to 100+ in “double” cultivars), pistillate, fertile (except “double” cultivars); corollas yellow or orange, red-brown (with or without yellow/orange), or white. |
||||||||||||
Disc florets | 6–120+, bisexual, fertile; corollas greenish yellow to orange, sometimes tipped with red or red-brown, tubes much longer than or about equaling funnelform throats, lobes 5, deltate to lance-linear (equal or 2 sinuses deeper than others). |
||||||||||||
Phyllaries | persistent, 3–21+ in 1–2 series (connate to 7/8+ their lengths, usually streaked and/or dotted with oil-glands). |
||||||||||||
Calyculi | 0. |
||||||||||||
Heads | radiate or discoid, borne singly or in ± corymbiform arrays. |
||||||||||||
Cypselae | narrowly obpyramidal or fusiform-terete, sometimes weakly flattened, glabrous or hairy; pappi persistent, of 2–5(–10) dissimilar, distinct or connate scales in ± 1 series: 0–5+ oblong to lanceolate, erose-truncate or laciniate plus 0–2(–5) longer, subulate to aristate. |
||||||||||||
x | = 12. |
||||||||||||
Tagetes |
|||||||||||||
Distribution |
Tropical and warm-temperate America; especially Mexico [Introduced in Old World] |
||||||||||||
Discussion | Species 40+ (4 in the flora). Some Tagetes species (e.g., T. erecta) produce nematicidal thiophenes in their roots and have been shown to be effective controls for nematodes in diverse crops (cf., http://www.ncagr.com/agronomi/nnote1.htm). Reports of “Tagetes minima L.” for Pennsylvania (cf. http://plants.usda.gov) are evidently rooted in an error for T. minuta. Report of T. pusilla Kunth (= T. filifolia Lagasca) for Maryland (http://plants.usda.gov) was not verified for this treatment. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||||||
Key |
|
||||||||||||
Source | FNA vol. 21, p. 235. | ||||||||||||
Parent taxa | |||||||||||||
Subordinate taxa | |||||||||||||
Name authority | Linnaeus: Sp. Pl. 2: 887. (1753): Gen. Pl. ed. 5, 378. (1754) | ||||||||||||
Web links |