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) ovatelanceolate 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 in Europe, Pacific Islands (New Zealand)

Discussion

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

... more about "Ageratina adenophora"
stipitate +  and sessile-glandular +
stipitate-glandular +
not tailed +, truncate +, rounded +  and obtuse +
acute;acute;acuminate +
scarious +
usually ovate +  and lanceolate +
usually terete +  and clavate +
indeterminate +  and determinate +
Guy L. Nesom +
(Sprengel) R. M. King & H. Robinson +
cuneate +  and obtuse +
enlarged +
Eupatorium adenophorum +
3(-5)-nerved +
5.5 cm55 mm <br />0.055 m <br /> (8 cm80 mm <br />0.08 m <br />) +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
2.5 cm25 mm <br />0.025 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
dissected +, lobed +, toothed +  and entire +
ovate-deltate;lanceolate-ovate +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
papillate +  and rugose +
(4-)5-angled;10-ribbed +
Crofton weed +  and sticky snakeroot +
pink-tinged +  and white +
scabrellous +
fusiform +  and prismatic +
fertile +  and bisexual +
Intoduced +, Calif. +, Mexico +, also in Europe +  and Pacific Islands (New Zealand) +
400–900 m +
puberulent +, pilose +, hispidulous +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Stream margins, ditches, road embankments, hillsides +
indeterminate +
each +  and sessile +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
campanulate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
hispidulous +
lanceolate +  and lance-linear +
2-carpellate +
persistent +
viscid-puberulent +  and stipitate-glandular +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
Flowering Mar–Aug(–Sep). +
2-nerved +  and 0-nerved +
8 +  and 30 +
subequal +  and unequal +
bearing subulate enations +, hairy +  and bristly +
exalbuminous +
Introduced +
stipitate-glandular +
appendaged +  and truncate +
hirsutulous +
papillate +
Compositae +
Ageratina adenophora +
Ageratina +
species +
obconic +  and campanulate +