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Key to families | Table of families and genera

Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.


Perennial herb, subshrub [shrub]. Leaf: cauline, opposite or distal alternate, petioled; blade elliptic to triangular, entire or toothed, generally 3-veined from base. Inflorescence: heads discoid, 1 or in ± flat-topped cyme-like clusters; involucre bell-shaped, phyllaries ± equal, in 1–2(3) series, linear to narrowly lanceolate; receptacle flat to conic, epaleate. Flower: 10–60; corolla ± white to pink-tinged or lavender, cylindric (or throat wider); style branches linear. Fruit: 5-angled, generally 5-ribbed; pappus of 5–40 slender scabrous bristles, often easily detached.
± 250 species: North America to South America. (Latin: resembling Ageratum) [King & Robinson 1987 Monogr Syst Bot Missouri Bot Gard 22:428–436; Nesom 2006 FNANM 21:547–553]
Unabridged references: [Nesom 2006 FNANM 21:547–553]

Key to Ageratina

1. Heads generally solitary (rarely 2–3) ..... A. shastensis

1' Heads clustered

2. Leaves alternate distally on stem; heads 8–10 mm ..... A. occidentalis

2' Leaves opposite throughout; heads 6–8 mm

3. Leaf blade generally 40–100 mm; petiole generally 20–40 mm ..... A. adenophora

3' Leaf blade generally 15–55 mm; petiole generally 5–10 mm ..... A. herbacea


Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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