Pentacalia Cass. (Compositae, Senecioneae) is a neotropical plant genus distributed from southern Mexico to northwestern Argentina, plus two disjunct species occurring in eastern Brazil. The Andes of Colombia, Ecuador, and Peru are the center of diversity of the genus, with most species thriving in montane forests. As currently circumscribed, it includes c. 162 species. These are scandent woody plants with alternate (very rarely opposite), simple leaves, usually corymbiform, thyrsoid-paniculiform or racemiform synflorescences, involucres with supplementary bracts at the base (calycle), radiate, disciform, or discoid capitula with yellow or white corollas, stamens with balustriform filament collar and caudate anther bases, styles with truncate to obtuse branches that usually have a crown of sweeping trichomes, and glabrous or pubescent achenes with a capillary pappus composed of barbellate bristles. The first comprehensive revision of this genus in Ecuador recognizing 27 species is presented here. Pentacalia campii (Cuatrec.) Cuatrec. is synonymized with P. corazonensis (Hieron.) Cuatrec., as well as P. carchiensis (Cuatrec.) Cuatrec. with P. aschersoniana (Hieron.) Cuatrec., P. carmelana H. Rob. & Cuatrec. with P. huilensis (Cuatrec.) Cuatrec., P. cazaletii H. Rob. & Cuatrec. with P. zakii H. Rob. & Cuatrec., P. chachapoyensis (Greenm.) Cuatrec. with P. theifolia (Benth.) Cuatrec., P. gibbiflora (Cuatrec.) Cuatrec. with P. oronocensis (DC.) Cuatrec., and both P. mikanioides J. Calvo and P. zamorana H. Rob. & Cuatrec. with P. millei (Greenm.) Cuatrec. The names Senecio disciformis Hieron. and Pentacalia floribunda Cuatrec. are lectotypified, and an epitype is designated for Senecio disciformis. Four new taxa are described, i.e., Pentacalia celicana J. Calvo & G. Benítez, P. nordenstamii J. Calvo, P. oellgaardii J. Calvo, and P. luteynorum subsp. lutea J. Calvo. Descriptions and distribution maps are provided for all accepted species, in addition to an identification key. Pictures of living plants are provided for 19 species. Fifteen (15) species are illustrated, 13 of them for the first time.

Calvo, Joel. Taxonomic revision of the genus Pentacalia (Compositae, Senecioneae) in Ecuador / J. Calvo ; editor-in-chief: M. W. Callmander. – Geneve : Conservatoire et Jardin botanique de Geneve, 2024 - (Boissiera : systematic botany monographs ; Vol. 74).Ind. of sci. names: p. 95.