Dicomeae

Perennial herbs, shrubs or small trees without latex; leaves alternate; heads discoid or radiate, variable in size; invo- lucre hemispherical to obconic, bracts imbricate often with hyaline margins: receptacle epaleate (rarely paleate), alveolate; corollas white, yellow, cream to pink or mauve; ray corollas bilabiate (inner lips coiled or not) or true rays with three teeth; disc corollas with five lobes of equal size, deeply divided; anther apical appendage acute to acuminate, thecae with spurs (calcarate), rarely without them (ecalcarate), and tails (caudate); pollen sub-oblate to prolate, micro-echinate or echinate; styles thick, deeply or shallowly divided, with a subacute to rounded apex and apical or subapical acute sweeping hairs, sometimes recurving at maturity; achenes often obconic but also narrowly oblong to broadly cylindrical with twin hairs; pappus of scabrid to plumose bristles or scales, pluriseri- ate, isomorphic or dimorphic.

Diagnostic Features

The core group of genera (Dicoma, Pasaccardoa, Mac- ledium, and Cloiselia) of this tribe is characterized by: pungent phyllaries without resin ducts (or ducts reduced); presence of star-shaped calcium oxalate crystals in the corollas, anther filaments and styles; anther tails long tapering; pollen slightly echinate; style branches straight and adjacent; and achenes broadly obconic to cylindri- cal with twin hairs and without a carpopodium. The remaining three genera (Pleiotaxis, Erythrocephalum and Gladiopappus) are rather different from this core group of Dicomeae and their inclusion in this tribe is provisional. Pleiotaxis and Erythrocephalum can be distinguished by the presence of phyllaries not pungent with resin ducts, calcium oxalate crystals not star-shaped, anther tails with subacute to subrounded apex, style branches separate and often curved, achenes ellipsoid and with carpopodium, whereas Gladiopappus is characterized by phyllaries with rounded apex, unisexual florets among the bisexual disc florets, marginal florets of the capitula being truly bi- labiate with coiled adaxial lobes, and achenes broadly obconic without twin hairs.

Geographic distribution

Tropical and southern Africa, includ- ing Madagascar and two species range outward to the Arabian Peninsula, India, and Pakistan.