97. Pluchea Cass. (marsh fleabane)

Plants annual or perennial herbs (woody elsewhere), fibrous-rooted, sometimes with short rhizomes, usually glandular, the sap not milky. Stems erect or ascending, hairy, unbranched or few-branched toward the tip, not spiny or prickly. Leaves alternate, not spiny or prickly, sometimes slightly succulent, sessile or short-petiolate. Leaf blades simple, the margins toothed. Inflorescences mostly terminal panicles or the stem branches with a small cluster of heads at the tip. Heads appearing discoid. Involucre urn-shaped to hemispherical or somewhat bell-shaped, with several series of more or less overlapping bracts, the inner series progressively longer, these usually appressed, not spiny or tuberculate, usually glandular. Receptacle flat, naked. Inner florets few, appearing perfect but mostly functionally staminate (the style branches usually not spreading at maturity), the corolla with short lobes. Outer florets more numerous, pistillate (lacking stamens), the corolla very slender and shorter than the style, the lobes very short. Pappus a ring of numerous capillary bristles, these finely toothed, persistent at fruiting. Stamens with the filaments not fused together, the anthers fused into a tube, each tip with a short, often indistinct appendage, each base prolonged into a pair of slender lobes. Style branches not flattened, each with a stigmatic line along each inner margin, the sterile tip rounded, hairy. Fruits 0.6–1.0 mm long, cylindrical, with 4–6 ribs, not winged, not beaked, pinkish tan, hairy, at least along the ribs. 50–80 species, nearly worldwide.

Plants of Pluchea usually are quite aromatic when crushed or bruised, with a camphorlike or musky odor. Steyermark (1963) likened the odor of P. camphorata to that of a skunk. Native Americans used some species medicinally for diarrhea, fever, skin ailments, and hemorrhoids, and also as a sedative (Moerman, 1998).