Tithonia rotundifolia

(Miller) S. F. Blake

Contr. Gray Herb. 52: 41. 1917.

Basionym: Tagetes rotundifolia Miller Gard. Dict. ed. 8, Tagetes no. 4. 1768
Treatment appears in FNA Volume 21. Treatment on page 139.
Revision as of 21:36, 16 December 2019 by FNA>Volume Importer

Annuals, mostly 100–200(–400) cm. Leaves: petioles 3–8 cm; blades ± deltate to pentagonal, 7–38 × 7–30 cm, sometimes 3- or 5-lobed, abaxial faces glabrous or soft-pubescent. Peduncles 11–27 cm. Phyllaries 14–21 in (2–)3 series, lanceolate to linear; outer 17–30 × 4–7.5 mm, apices acute, abaxial faces usually densely puberulent; inner 16–28 × 5–8 mm, apices rounded to acute, abaxial faces usually densely puberulent. Paleae 11.5–15 × 2–3 mm, mucros 2.5–5.5 mm. Ray florets 8–13; corollas usually orange, sometimes yellow, laminae oval to oblong, 20–33 × 6–17 mm. Disc florets 60–90. Cypselae 5–7. 2n = 34.


Phenology: Flowering Nov.
Habitat: –Jan. Disturbed sites
Elevation: 0–20+ m

Distribution

V21-337-distribution-map.gif

Fla., La., Mexico, West Indies, Central America.

Discussion

Tithonia rotundifolia is widely cultivated in warm climates and may persist after plantings (e.g., in Asia).

Selected References

None.

Lower Taxa

None.