Tithonia thurberi A. Gray
Family: Asteraceae
Arizona sunflowerweed,  more...
[Tithonia palmeri ]
Tithonia thurberi image
Anthony Mendoza  
Annuals, 70-200 cm. Leaves: petioles 0-3.3 cm; blades deltate, 7-28 × 5.5-21.5 cm, abaxial faces sparsely hirsute (hairs larger on veins). Peduncles 17-36 cm. Phyllaries 13-16 in 3 series, linear to spatulate; outer 8-15 × 2.5-4.5 mm, apices acute, abaxial faces puberulent; inner 12-15.5 × 3.5-7 mm, apices acute, abaxial faces glabrous. Paleae 11-16.5 × 2-4 mm, mucros 3 mm. Ray florets 7-10; corollas yellow, laminae oblong, 9-15 × 4-6 mm. Disc florets 40-60. Cypselae 6-9 mm. 2n = 34. Flowering Aug-Sep. Disturbed areas, canyons, watercourses; 900-1000 m; Ariz.; Mexico (Sonora).
FNA 2006, Wiggins 1964, Kearney and Peebles 1969
Duration: Annual Nativity: Native Lifeform: Forb/Herb General: Slender, moderately branched annual 0.5-2 m tall with whitish, striate stems sparsely to densely hispid-pilose with spreading; tuberculate-based, coarse hairs interspersed with finer ones, eventually glabrate. Leaves: Lower leaves opposite, upper ones alternate, blades ovate to broadly triangular-ovate, acute to acuminate, 3-27 cm wide, 5-28 cm long, cuneately decurrent along petiole from a cuneate to broadly cordate base, crenate-dentate with mucronulate teeth, deep green and hispidulous with incurved hairs above, paler green and sparsely granular or hispidulous and hispid-pilose along veins beneath, petioles 2-10 cm long. Flowers: Fistulose peduncles, striate, 10-30 cm long, spreadingly hispid-pilose and finely hispidulous; heads 2.5-3.5 cm wide, involucres of graduated bracts in 3 series, 1-2 cm tall, outer bracts lanceolate, oblong-ovate, acute to acuminate; rays 5-10, orange-yellow, oval-oblong 4-6 mm wide, 7-12 mm long; disk corollas 6-6.2 mm long, hispidulous on lobes, glandular-pilosulous below, tube about 1 mm long, throat cylindrical. Fruits: Oblong-obovate cypselae, 8.5-9 mm long, pappus awn solitary on outer angle of cypselae, linear-subulate, 5-5.8 mm long. Ecology: Found in rich soil along banks of streams, ditches, and margins of water bodies from 3,000-4,500 ft (914-1372 m); flowers August-September. Notes: This plant is distinguishable by its orange rays and sunflower-like leaves and habit. Ethnobotany: Unknown Etymology: Tithonia comes from the Latin Tithon, who was the husband of Aurora, while thurberi is named for Dr. George Thurber (1821-1890). Synonyms: None Editor: SBuckley, 2010
Tithonia thurberi image
Anthony Mendoza  
Tithonia thurberi image
Anthony Mendoza  
Tithonia thurberi image
Thomas Van Devender  
Tithonia thurberi image
Thomas Van Devender  
Tithonia thurberi image
Montañez, M.P.  
Tithonia thurberi image
Sue Carnahan  
Tithonia thurberi image
Thomas Van Devender  
Tithonia thurberi image
Rorabaugh, J.C.  
Tithonia thurberi image
Sue Carnahan  
Tithonia thurberi image
Thomas Van Devender  
Tithonia thurberi image
Sue Carnahan  
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Thomas Van Devender  
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Thomas Van Devender  
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image
Tithonia thurberi image