Taxonomic revision of Dasyphyllum sect. Macrocephala (Asteraceae: Barnadesioideae)

Dasyphyllum sect. Macrocephala is restricted to the Cerrado, Caatinga, and Atlantic Forest biomes of Brazil, spreading into similar areas in Bolivia and Paraguay. The six recognized species in this section are monoecious shrubs with erect or decumbent branches, single or paired, rarely fasciculate, straight or curved axillary spines, leaves with apiculate or aristate apices, 5–7 basally or suprabasally acrodromous veins, sessile capitula, usually solitary or in groups of two to four, a campanulate or infundibuliform involucre generally longer than 20 mm, and with hermaphroditic florets usually with liguliform corollas and externally sericeous lobes. An identification key, descriptions, comments regarding morphology and taxonomy, maps showing geographical distribution, and illustrations are presented, together with 17 new synonyms and 18 typifications.