Ageratina adenophora

(Sprengel) R. M. King & H. Robinson
Phytologia 19: 211. 1970.
Common names: Crofton weed sticky snakeroot
Introduced
Basionym: Eupatorium adenophorum Sprengel Syst. Veg. 3: 420. 1826,; 4(qto.): 122, plate 346. 1820, not Michaux 1803
Treatment appears in FNA Volume 21. Treatment on page 553. Mentioned on page 547, 548.

Subshrubs, 50–220 cm. Stems (usually purplish when young) erect, stipitate-glandular. Leaves opposite; petioles 10–25 mm; blades (abaxially purple) ovate-lanceolate or ovate-deltate to lanceolate-ovate, (1.5–)2.5–5.5(–8) × 1.5–4(–6) cm, bases cuneate to obtuse or nearly truncate, margins serrate, apices acute to acuminate, abaxial faces stipitate- to sessile-glandular. Heads clustered. Peduncles 5–12 mm, densely stipitate-glandular and sometimes also sparsely viscid-puberulent. Involucres 3.5–4 mm. Phyllaries: apices acute, abaxial faces stipitate-glandular. Corollas white, pink-tinged, lobes sparsely hispidulous. Cypselae glabrous. 2n = 51.


Phenology: Flowering Mar–Aug(–Sep).
Habitat: Stream margins, ditches, road embankments, hillsides
Elevation: 400–900 m

Distribution

V21-1404-distribution-map.gif

Intoduced, Calif., Mexico, also introduced in Europe, Pacific Islands (New Zealand).

Discussion

Selected References

None.

Lower Taxa

None.

... more about "Ageratina adenophora"
Guy L. Nesom +
(Sprengel) R. M. King & H. Robinson +
Eupatorium adenophorum +
Crofton weed +  and sticky snakeroot +
Intoduced +, Calif. +, Mexico +, also introduced in Europe +  and Pacific Islands (New Zealand). +
400–900 m +
Stream margins, ditches, road embankments, hillsides +
Flowering Mar–Aug(–Sep). +
Introduced +
Compositae +
Ageratina adenophora +
Ageratina +
species +