Carphephorus, commonly called chaffheads, is a small genus of perennial herbaceous plants in the family Asteraceae (order Asterales), endemic to the southeastern United States. The genus was described by the botanist Cassini in 1816, with the name derived from the Greek words karphos (chaff) and phoros (bearing), a reference to the chaff-like receptacular paleae found in most species.
Plants in this genus grow from a relatively thick caudex with a fibrous root system. The stems are erect, typically unbranched and somewhat scapiform, reaching 20 to 60 centimetres or more in height. Leaves are arranged alternately, usually pressed upward against the stem; the blades are generally 1-nerved, ranging from linear to oblanceolate or spatulate in outline, with entire or remotely toothed margins, and are glabrous to hairy and often dotted with glands. The flower heads are discoid — composed entirely of tubular disc florets — and are borne in flat-topped corymbiform or elongated paniculiform arrays. Each head contains 12 to 35 florets with corollas usually in shades of lavender to dark magenta or pinkish purple, sometimes blue. The fruits are prismatic cypselae with approximately 10 ribs, topped by a persistent pappus of 35 to 40 barbellulate bristles.
The genus comprises 7 species, all native to the southeastern United States from Louisiana northward to Virginia. Notable members include Carphephorus odoratissimus (vanilla plant or deer's tongue), valued historically for its vanilla-scented foliage, and Carphephorus corymbosus (Florida paintbrush), a showy species of pine flatwoods.
The generic boundaries of Carphephorus have been debated. The closely related genera Trilisa and Litrisa have been maintained as distinct by some authorities on the basis of smaller heads and the absence of receptacular paleae, while other prominent systematists have treated their species within a single broad Carphephorus. Molecular studies may yet clarify whether one or both segregates deserve recognition.
Etymology
The genus name Carphephorus is formed from the Greek words karphos (chaff) and phoros (bearing), referring to the chaff-like paleae (scales) on the receptacle of most species in the genus — a feature used to distinguish it from the related genus Trilisa. The common name "chaffheads" reflects the same morphological feature.
Distribution
All 7 species of Carphephorus are native to the southeastern United States, with the genus ranging from Louisiana eastward through the Gulf and Atlantic coastal plain states to Virginia. The plants are characteristic of fire-maintained habitats such as pine flatwoods, pine savannas, and seasonally wet sandy soils in this region.
Taxonomy Notes
The placement of the closely related genera Trilisa and Litrisa within or alongside Carphephorus has been a long-running taxonomic question. King and Robinson (1987) maintained Trilisa and Litrisa as separate genera, citing differences in head size, phyllary number, and the absence of receptacular paleae. However, Hebert (1968), Correa and Wilbur (1969), and Cronquist (1980) treated all taxa within a single expanded Carphephorus, and this broader circumscription is followed in the Flora of North America treatment. Forthcoming molecular studies noted in FNA may support recognition of one or both segregates.
