Tithonia
Tithonia is a genus of flowering plants in the sunflower tribe within the family Asteraceae.
Tithonia has a center of distribution in Mexico but with one species extending into the Southwestern United States and several native to Central America. Two species, T. diversifolia and T. rotundifolia, are widely cultivated and have escaped to become weeds in tropical and subtropical areas around the world. The distinguishing feature of the genus is the peduncle, which is fistulose. The plants are coarse annual or perennial herbs or shrubs, and one species, T. koelzii, is a small tree.
; Species
- Tithonia brachypappa B.L.Rob. - San Luis Potosí
- Tithonia calva Sch.Bip. - Durango, Sinaloa
- Tithonia diversifolia A.Gray - Tree Marigold - Mexico, Central America; naturalized in Asia, Australia, Africa, South America, Florida, Texas, various oceanic islands
- Tithonia fruticosa Canby & Rose - Chihuahua, Durango, Sonora, Sinaloa
- Tithonia helianthoides Bernh.
- Tithonia hondurensis La Duke - Belize, Honduras
- Tithonia koelzii McVaugh - Jalisco
- Tithonia longiradiata S.F.Blake - Mexico, Central America
- Tithonia pedunculata Cronquist - Oaxaca
- Tithonia pittieri S.F.Blake - Central America
- Tithonia rotundifolia S.F.Blake - Mexico, Central America; naturalized in Florida, Louisiana, South America
- Tithonia tagetiflora Desf. - Veracruz
- Tithonia thurberi Gray - Arizona Sunflower Weed - Chihuahua, Sonora, Arizona
- Tithonia tubiformis Cass. - Mexico, Central America; naturalized in Argentina
; formerly included
see Comaclinium Enceliopsis Lasianthaea Viguiera
