Ambrosia ilicifolia

(A. Gray) W. W. Payne
J. Arnold Arbor. 45: 425. 1964.
Basionym: Franseria ilicifolia A. Gray Proc. Amer. Acad. Arts 11: 77. 1876
Treatment appears in FNA Volume 21. Treatment on page 12. Mentioned on page 10.

Shrubs, 30–50(–120+) cm. Stems erect. Leaves mostly alternate; petioles 0–2 mm; blades (green) elliptic to ovate, 25–60+ × 12–35+ mm, bases rounded to truncate, margins spiny-toothed, abaxial and adaxial faces ± hirtellous (on veins) and stipitate-glandular. Pistillate heads clustered, proximal to staminates; florets 2. Staminate heads: peduncles 2–8(–12) mm; involucres ± saucer-shaped, 9–15+ mm diam., ± hirtellous and stipitate-glandular; florets 20–40+. Burs: bodies ± globose, 6–8 mm, stipitate-glandular, spines 40–50+, scattered, subulate, 4–6 mm, tips straight or ± uncinate. 2n = 36.

Phenology: Flowering Jan–Apr.
Habitat: Sandy washes, benches
Elevation: 30–500 m



Ariz., Calif., Mexico (Baja California, Sonora).


Selected References


Lower Taxa