Ageratina adenophora |
Ageratina wrightii |
|
---|---|---|
Crofton weed, eupatory, Mexican devil, sticky snakeroot, thoroughwort |
Wright's snakeroot |
|
Habit | Subshrubs, 50–220 cm. | Shrubs, 50–150 cm. |
Stems | (usually purplish when young) erect, stipitate-glandular. |
erect, puberulous. |
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. |
opposite proximally, alternate on distal 1/3–1/2 of stem; petioles narrowly winged, 3–5(–8) mm; blades ovate to deltate-ovate, mostly 1–2 × 0.5–1.5(–2) cm, bases truncate to cuneate or attenuate, margins entire or shallowly crenate, apices acute to blunt or obtuse, abaxial faces gland-dotted. |
Peduncles | 5–12 mm, densely stipitate-glandular and sometimes also sparsely viscid-puberulent. |
1–3 mm, puberulent. |
Involucres | 3.5–4 mm. |
3.5–4.5 mm. |
Corollas | white, pink-tinged, lobes sparsely hispidulous. |
pinkish white to pink, glabrous. |
Phyllaries | apices acute, abaxial faces stipitate-glandular. |
apices acute, abaxial faces puberulent. |
Heads | clustered. |
clustered. |
Cypselae | glabrous. |
sparsely hispidulous. |
2n | = 51. |
|
Ageratina adenophora |
Ageratina wrightii |
|
Phenology | Flowering Mar–Aug(–Sep). | Flowering (Jul–)Aug–Oct(–Nov). |
Habitat | Stream margins, ditches, road embankments, hillsides | Limestone slopes, ledges, alluvium, in brushy vegetation |
Elevation | 400–900 m (1300–3000 ft) | 1300–2200 m (4300–7200 ft) |
Distribution |
CA; Mexico; Intoduced [Also introduced in Europe, Pacific Islands (New Zealand)]
|
AZ; NM; TX; Mexico
|
Source | FNA vol. 21, p. 553. | FNA vol. 21, p. 552. |
Parent taxa | Asteraceae > tribe Eupatorieae > Ageratina | Asteraceae > tribe Eupatorieae > Ageratina |
Sibling taxa | ||
Synonyms | Eupatorium adenophorum | Eupatorium wrightii |
Name authority | (Sprengel) R. M. King & H. Robinson: Phytologia 19: 211. (1970) | (A. Gray) R. M. King & H. Robinson: Phytologia 19: 228. (1970) |
Web links |