Tagetes
Tagetes erecta
marigold
African marigold, African or French marigold, American marigold, Aztec marigold, French marigold, French or African marigold, Mexican marigold
erect, branched distally or ± throughout.
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).
blades 30–120(–250+) mm overall, principal lobes/leaflets 9–25, lanceolate to lance-linear, 15–25(–45+) × 3–8(–12+) mm.
30–100(–150+) mm.
narrowly cylindric or fusiform to turbinate or broadly campanulate, 1–12+ mm diam.
10–22+ × (3–)5–12+ mm.
convex to conic, smooth or finely pitted, epaleate.
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.
(3–)5–8+ (to 100+ in “double” cultivars);
laminae yellow to orange, red-brown (sometimes particolored: yellow/red-brown), or white (some cultivars), ± flabellate to oval-quadrate, (2–)12–18(–25+) mm.
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).
(10–)50–120+;
corollas 7–12+ mm.
persistent, 3–21+ in 1–2 series (connate to 7/8+ their lengths, usually streaked and/or dotted with oil-glands).
0.
radiate or discoid, borne singly or in ± corymbiform arrays.
borne ± singly.
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.
6–11 mm;
pappi of 0–2, ± subulate-aristate scales 6–12+ mm plus 2–4 distinct or connate, linear-oblong, ± erose scales 2–6+ mm.
= 12.
= 24, 48.
Tagetes
Tagetes erecta
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.)
Cultivars of Tagetes erecta are widely grown in gardens and, commercially, for cut flowers. They often persist after abandoned plantings. Tetraploid plants (2n = 48) with smaller involucres and wholly or partially red-brown corollas included here in T. erecta have been called T. patula by some botanists.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaf lobes (or simple blades) linear to filiform, 10–25(–35+) × 0.5–1.5 mm | T. micrantha |
1. Leaf lobes lance-elliptic or lanceolate to lance-linear, 12–25(–50+) × (2–)4–8(–12+) mm | → 2 |
2. Perennials, subshrubs, or shrubs | T. lemmonii |
2. Annuals | → 3 |
3. Heads in ± corymbiform clusters; peduncles 1–5+ mm; involucres 7–10+ × 1.5–3 mm | T. minuta |
3. Heads borne ± singly; peduncles 30–100(–150+) mm; involucres 10–22 × (3–)5–12+ mm | T. erecta |
OR
Flora NW
PNW Herbaria- Local floras:
CA - Local Web sites: CalFlora, CalPhotos,
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
LA Plants, 
MD Biodiversity, 
MO Plants 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
