Chile: Coquimbo Region, Elqui Province, bushy field near El Arrayán about 25 km north from La Serena, October 2003, P. Ravenna 5023 (Holotype BA; isotypes Herb. Rav., CONC). Neotype:—CHILE. Coquimbo Region: Elqui Province, Panamericana Norte, between La Serena and Caleta Hornos, before Juan Soldado bridge, (29°39’ S, 71°18’ W), 80–190 m, 3 October 1991, Ch. von Bohlen 1209 (holotype SGO 133272!).
- Penneckamp et al.
Shrub 1.5–2 m tall,
P. formosus resembles P. floccosus, which differs by lacking woolly-tomentose stems. P. formosus is also similar to P. chilensis, from which the former differs in the lower surface of the leaves being piuberulent.
Distribution and habitat
Restricted to sclerophyllous shrublands in coastal areas of Juan Soldado north of La Serena, Coquimbo Region (ca. 29°39’31.00” S, 71°18’42.00” W) and in the range of Chañaral de Aceituno (ca. 29°3’60.00” S, 71°29’0.00” W) in the Atacama Region (Penneckamp et al., 2020)
One might speculate that based on intermediate morphological features and distribution, P. formosus might have originated through hybridization between P. chilensis and P. floccosus. This might be an example of a recent speciation radiation that occurred in this region of the distribution of Plectocephalus (A. Susanna, pers. comm. in Penneckamp, 2020).
Penneckamp et al.
Penneckamp, , D , Chaura, R , Rojas, G. and Stuessy, T. 2020. Taxonomic notes on Plectocephalus (Centaurea) s.l., Centaureinae, Asteraceae) from Chile, including new combinations and synonyms. Phytotaxa 437(4) 227-246