Directory       News       Site Map       Home
    Jepson eFlora
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.



Linda E. Watson

Annual, perennial herb; <= 150 cm, glabrous or hairy, often aromatic. Stem: 1 or 2–5+, prostrate to erect, branched proximally and/or distally, glabrous or hairy. Leaf: basal and/or cauline, alternate, petioled or sessile, ovate or elliptic to obovate or spoon-shaped, generally 1–3-pinnately lobed, ultimate margins entire, crenate, or dentate. Inflorescence: heads radiate or radiant to disciform [discoid], generally in ± flat-topped clusters, subsessile or peduncled; involucre generally hemispheric or wider; phyllaries 30–60+, ± equal or graduated in 3–5+ series, free, persistent, lanceolate to oblong or ± ovate, outer sometimes keeled, margins and tips scarious, pale to sometimes ± brown or black; receptacle flat to conic or hemispheric, epaleate, glabrous or hairy. Ray flower: 0 or 10–21, pistillate or sterile, ray oblong to fan-shaped, ± yellow or white [pink] (in disciform heads, peripheral pistillate flowers 8–30+, corolla pale yellow, ± bilateral, 3–4-lobed). Disk flower: 60–300+; corolla yellow, tube < narrowly funnel-shaped throat, lobes (4)5, triangular; anther tip narrowly triangular; style tips truncate, brush-like. Fruit: obconic or ± cylindric, generally 5–10 ribbed, generally resin-gland-dotted; pappus a crown of short scales.
160 species: Europe, Asia, North America. (Possibly Greek through Latin: immortality) [Watson 2006 FNANM 19:489–491]

Key to Tanacetum

1. Leaf blade generally 1–2-pinnately lobed, 1° lobes generally 3–5 pairs, oblong to ± ovate, at least abaxial face generally puberulent; ray flowers generally 10–21+; rays white 2–8(12+) mm; pappus 0 or 0.1–0.2+ mm ..... T. parthenium

1' Leaf blade 2–3-pinnately lobed, 1° lobes 4–24+ pairs, linear to ± oblong or elliptic, generally cobwebby to long-soft-hairy, sometimes ± glabrous; ray flowers 0 or 8–30+, rays 1–8+ mm, yellow; pappus 0.1–0.5+ mm

2. Leaf blade generally long-soft-hairy to tomentose, sometimes ± glabrous; heads disciform to ± radiant or ± radiate, (1)5–12(20+) in ± flat-topped cluster; involucre 8–22+ mm diam ..... T. bipinnatum

2' Leaf blade glabrous or sparsely hairy; heads disciform, 20–200 in ± flat-topped cluster; involucre 5–10 mm diam ..... T. vulgare


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].
We encourage links to these pages, but the content may not be downloaded for reposting, repackaging, redistributing, or sale in any form, without written permission from The Jepson Herbarium.