Ageratina herbacea

(A. Gray) R. M. King & H. Robinson

Phytologia 19: 222. 1970

Common names: Fragrant snakeroot
Basionyms: Eupatorium ageratifolium var. herbaceum A. Gray Smithsonian Contr. Knowl. 5(6): 74. 1853
Synonyms: Eupatorium herbaceum (A. Gray) Greene
Treatment appears in FNA Volume 21. Treatment on page 551. Mentioned on page 548.
Perennials or subshrubs, (20–)30–60(–80) cm (woody crowns and woody rhizomes). Stems erect (brittle), minutely puberulent. Leaves opposite; petioles 10–25 mm; blades triangular to lanceolate-ovate or ovate, 2–5(–7) × 1.5–3.5(–4.5) cm, bases truncate to shallowly cordate, margins dentate to serrate-dentate, abaxial faces sparsely hispidulous to glabrate, eglandular. Heads clustered. Peduncles 4–15 mm, puberulent. Involucres 4–5 mm. Phyllaries: apices acute, abaxial faces granular-puberulent. Corollas white, glabrous. Cypselae finely strigose-hispidulous. 2n = 34.

Phenology: Flowering (Jul–)Aug–Oct.
Habitat: Pine, pine-oak, juniper, and pinyon-juniper woodlands, rocks along streams, slopes, ridges, washes
Elevation: 1400–2700(–2900) m



Ariz., Calif., Colo., Nev., N.Mex., Tex., Utah, Mexico (Baja California, Chihuahua, Coahuila, Sonora).


Ageratina herbacea is recognized by the distinctive color of its usually yellow-green, sometimes grayish, leaves, granular-puberulent involucres (with minute, thickened, eglandular hairs), and woody rhizomes.

Selected References


Lower Taxa


Facts about "Ageratina herbacea"
AuthorGuy L. Nesom +
Authority(A. Gray) R. M. King & H. Robinson +
BasionymsEupatorium ageratifolium var. herbaceum +
Common nameFragrant snakeroot +
DistributionAriz. +, Calif. +, Colo. +, Nev. +, N.Mex. +, Tex. +, Utah +, Mexico (Baja California +, Chihuahua +, Coahuila + and Sonora). +
Elevation1400–2700(–2900) m +
HabitatPine, pine-oak, juniper, and pinyon-juniper woodlands, rocks along streams, slopes, ridges, washes +
IllustrationPresent +
Illustration copyrightFlora of North America Association +
IllustratorLinny Heagy +
PhenologyFlowering (Jul–)Aug–Oct. +
Publication titlePhytologia +
Publication year1970 +
ReferenceNone +
Source xml grained fna xml/V19-20-21/V21 1398.xml +
SynonymsEupatorium herbaceum +
Taxon familyAsteraceae +
Taxon nameAgeratina herbacea +
Taxon parentAgeratina +
Taxon rankspecies +
VolumeVolume 21 +