92. Tagetes L. (marigold)
Plants annual
(perennials elsewhere), aromatic, with taproots. Stems erect or ascending,
unbranched to several-branched, with several fine longitudinal ridges and
grooves, glabrous. Leaves mostly alternate, the lowermost few sometimes
opposite, mostly sessile, the bases of each pair slightly expanded and wrapped
around the stem. Leaf blades 3–12 cm long, elliptic to ovate in outline, 1 or 2
times pinnately dissected with 9–25 primary lobes, the ultimate segments linear
to narrowly lanceolate, the margins otherwise entire or with a few irregular
teeth, the surfaces glabrous and dotted with scattered, brownish yellow,
sessile oil glands. Inflorescences of solitary, mostly long-stalked heads at
the branch tips or less commonly axillary from the uppermost leaves. Heads
radiate (discoid elsewhere). Involucre cup-shaped to slightly bell-shaped, the
disc 5–12 mm in diameter, the bracts in 1 series. Involucral bracts 7–10, fused
more than 2/3 of the way to the tip, with triangular teeth, the surface
glabrous but dotted or lined with conspicuous, sessile, yellowish brown oil
glands, somewhat thin and membranous, green but often pinkish- or
purplish-tinged. Receptacle convex or somewhat conical, not or only slightly
elongating as the fruits mature, with minute, irregular ridges around the
attachment points of the florets. Ray florets 5–8 (commonly numerous in doubled
horticultural forms), pistillate, showy, the corolla 10–30 mm long, relatively
broad, yellow to orange, sometimes red or reddish brown toward the base. Disc
florets 40–120, perfect, the corolla greenish yellow to orange, the tube
slender, not expanded at the base nor persistent at fruiting, glabrous, the
lobes sometimes hairy along the margins. Style branches with the sterile tip
elongate and with a small, more or less spherical, expanded portion at the very
tip. Pappus of 5–12 slender, unequal scales, these sometimes fused at the base,
straw-colored or orangish brown, the margins irregular or more commonly with
ascending barbs or teeth. Fruits linear to very narrowly wedge-shaped in
outline, 4- or 5-angled and slightly flattened, the surface usually moderately
pubescent with short, ascending hairs, especially along the angles, black.
About 40 species, North America to South America; introduced in the Old World.
The two species
of marigold in the Missouri flora are both escapes from cultivation and are
sometimes difficult to differentiate (Neher, 1966). Some botanists have treated
them as components of a single species. A third, very different, cultivated
species of Tagetes is likely to be encountered in the future as an
escape. Tagetes minuta L. (variously known as chinchilla, anisillo, tall
khakiweed, Mexican marigold, and stinkweed, among other names) is widely grown
as a seasoning for meats, soups, and vegetables. It is a densely branched
annual with erect stems 30–100 cm long and pinnately dissected leaves. However,
it differs from the other cultivated marigolds in Missouri in its more numerous
heads with the slender, nearly cylindrical involucre 8–12 mm long, only 1–3 ray
florets with inconspicuous corollas 1–2 mm long, only 3–5 disc florets, and
somewhat shorter pappus and fruits.