Polymnia
Sp. Pl. 2: 926. 1753.
Gen. Pl. ed. 5, 396. 1754.
| Taxon | Illustrator ⠉ | |
|---|---|---|
 | Acanthospermum australe Polymnia canadensis Guizotia abyssinica | Barbara Alongi Linda Ann Vorobik Yevonn Wilson-Ramsey |
Annuals or perennials, 50–150+ cm (often rhizomatous). Stems erect, branched distally. Leaves all or mostly cauline; opposite; petiolate (petioles often ± winged, often with connate-perfoliate basal appendages); blades (pinnately nerved) deltate or rounded-rhombic to cordate or ovate, often raggedly pinnately lobed (lobes 3–11), ultimate margins coarsely toothed to denticulate or entire, faces pilose or pilosulous to hirtellous, or glabrate, or glabrous, glanddotted and/or stipitate-glandular. Heads usually radiate, rarely ± disciform, (2–5+) in loose to congested, corymbiform clusters. Calyculi 0. Involucres hemispheric, 4–15+ mm diam. Phyllaries persistent, 6–21+ in 2 series (distinct, outer 2–6 ovate to linear, ± herbaceous, inner ovate to lanceolate, subequal to or shorter than outer, more scarious, similar to paleae). Receptacles flat to convex, paleate (paleae obovate to oblanceolate or spatulate, herbaceous to scarious). Ray-florets 2–6, pistillate, fertile; corollas pale yellowish to whitish (tubes pilosulous, laminae ± cuneate to linear, 3-lobed, sometimes absent or nearly so). Disc-florets 12–30+, functionally staminate; corollas pale-yellow, tubes shorter than abruptly dilated throats, lobes 5, deltate to lanceovate. Cypselae plumply pyriform, ± obcompressed, 3–6-angled or ribbed, finely striate between ribs (narrowed at bases, patently inserted on receptacles, often minutely beaked), sparsely hirtellous or glabrate; pappi 0. x = 15.
Distribution
c, e North America
Discussion
Species 3 (3 in the flora).
Selected References
Lower Taxa
Key
| 1 | Annuals; blades of larger leaves shallowly, if at all, pinnately lobed | Polymnia cossatotensis |
| 1 | Perennials; blades of larger leaves usually deeply pinnately lobed | > 2 |
| 2 | Stems pilosulous to villous and/or stipitate-glandular; cypselae 3-angled or -ribbed | Polymnia canadensis |
| 2 | Stems glabrous or glabrate; cypselae 4–6-angled or -ribbed | Polymnia laevigata |