Ageratina rothrockii
Ageratina herbacea
Rothrock's snakeroot
desert ageratina, fragrant snakeroot, white thoroughwort
ascending to erect, puberulent to glabrate.
erect (brittle), minutely puberulent.
opposite;
petioles 2–20 mm;
blades (3–5-nerved) lanceolate to lanceolate-ovate, mostly 3–6 × (1.5–)2–3 cm, bases obtuse to truncate, margins serrate to crenate, apices acute to acuminate, sparsely puberulent abaxially, mostly along nerves.
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.
5–12(–20) mm, puberulent.
4–15 mm, puberulent.
5–7 mm.
4–5 mm.
white, lobes short-villous.
white, glabrous.
apices acute, abaxial faces glabrous or glabrescent, eglandular.
apices acute, abaxial faces granular-puberulent.
clustered.
clustered.
sparsely and finely strigose-hirsute.
finely strigose-hispidulous.
on label].
= 85 [ca. 100, fide A. M.
= 34.
Ageratina rothrockii
Ageratina herbacea
Ageratina rothrockii is similar to A. altissima, probably its western vicariant, and the two perhaps would be justifiably treated as conspecific.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
WildflowerSearch
iNaturalist
USDA Plants Database
CA
SW CO Wildflowers
