Ageratina adenophora

(Sprengel) R. M. King & H. Robinson

Phytologia 19: 211. 1970

Common names: Crofton weed sticky snakeroot
Basionyms: 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



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


Selected References


Lower Taxa


Facts about "Ageratina adenophora"
AuthorGuy L. Nesom +
Authority(Sprengel) R. M. King & H. Robinson +
BasionymsEupatorium adenophorum +
Common nameCrofton weed + and sticky snakeroot +
DistributionIntoduced +, Calif. +, Mexico +, also introduced in Europe + and Pacific Islands (New Zealand). +
Elevation400–900 m +
HabitatStream margins, ditches, road embankments, hillsides +
Illustration copyrightFlora of North America Association +
IllustratorLinny Heagy +
PhenologyFlowering Mar–Aug(–Sep). +
Publication titlePhytologia +
Publication year1970 +
ReferenceNone +
Source xml grained fna xml/V19-20-21/V21 1404.xml +
SynonymsCompositae +
Taxon familyAsteraceae +
Taxon nameAgeratina adenophora +
Taxon parentAgeratina +
Taxon rankspecies +
VolumeVolume 21 +