Acmella

Richard in C. H. Persoon

in C. H. Persoon, Syn. Pl. 2: 472. 1807

Etymology: From a Singhalese name for a plant now known as Blainvillea acmella (Linnaeus) Philipson
Treatment appears in FNA Volume 21. Treatment on page 132. Mentioned on page 64, 65, 67.
Annuals or perennials, 10–20(–30+) cm. Stems prostrate to erect, usually branched ± throughout. Leaves cauline; opposite; petiolate [± sessile]; blades (usually 3-nerved) ovate to rhombic or lanceolate [linear to filiform], bases ± cuneate, margins entire or toothed, faces sparsely pilose to strigillose, glabrescent. Heads radiate or discoid [disciform], borne singly at tips of branches [corymbiform arrays]. Involucres ± hemispheric to ovoid, 3–6+ mm diam. Phyllaries persistent, 8–15+ in 1–3 series (distinct, ovate to linear, subequal or outer longer). Receptacles conic, paleate (paleae falling with fruit, ± navicular, membranous to scarious, each about equaling subtended floret). Ray florets 0 or 5–20+, pistillate, fertile; corollas yellow to orange [white or purplish] (laminae ovate to linear) [wanting]. Disc florets 25–100(–200+) bisexual, fertile; corollas yellow [orange], tubes shorter than campanulate throats, lobes 4–5, deltate. Cypselae 2–3-angled (peripheral) or strongly compressed, ellipsoid to obovoid (glabrous or ciliate on the 2–3 angles or ribs); pappi 0, or fragile, of 1–3 awnlike bristles. x = 13.

Distribution

s United States, Mexico, West Indies, Central America, South America, introduced in Asia, Africa, Pacific Islands, Australia.

Discussion

Species 30 (2 in the flora).

Acmella pilosa R. K. Jansen has been reported as introduced in Florida (http://www.plantatlas.usf.edu); it differs from A. repens mainly by its more densely pilose stems and leaves and more truncate to cordate (versus cuneate) leaf bases.

Key

1 Petioles 3–40+ mm; leaf blades ovate to lance-ovate, mostly 20–40(–100) × 10–35 mm, margins dentate to denticulate or entire Acmella repens
1 Petioles 2–4 mm; leaf blades lanceolate, mostly 12–40 × 3–10 mm, margins usually sinuate-dentate, rarely entire Acmella pusilla
Facts about "Acmella"
AuthorJohn L. Strother +
AuthorityRichard in C. H. Persoon +
Distributions United States +, Mexico +, West Indies +, Central America +, South America +, introduced in Asia +, Africa +, Pacific Islands + and Australia. +
EtymologyFrom a Singhalese name for a plant now known as Blainvillea acmella (Linnaeus) Philipson +
IllustratorBarbara Alongi +
Publication titlein C. H. Persoon, Syn. Pl. +
Publication year1807 +
Referencejansen1985a +
Source xmlhttps://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f6b125a955440c0872999024f038d74684f65921/coarse grained fna xml/V19-20-21/V21 322.xml +
SynonymsUndefined (tribe Undefined) subtribe Enceliinae +, Undefined (tribe Undefined) subtribe Engelmanniinae +, Undefined (tribe Undefined) subtribe Spilanthinae +, Undefined (tribe Undefined) subtribe Verbesininae + and Undefined (tribe Undefined) subtribe Zinniinae +
Taxon familyAsteraceae +
Taxon nameAcmella +
Taxon parentAsteraceae (tribe Heliantheae) subtribe Ecliptinae +
Taxon rankgenus +
VolumeVolume 21 +