Macledium is a small genus of flowering plants in the daisy family Asteraceae, order Asterales. It is closely related to the genus Dicoma, from which it is distinguished by a suite of morphological and anatomical characters involving the phyllaries (the bracts enclosing the flower head), corolla, anthers, style, cypsela (the achene-like fruit), and seed coat (testa). Both Macledium and Dicoma are distributed largely across tropical and southern Africa.
Within southern Africa, the genus is informally divided into two ecological groups: Cape species (including M. relhanioides, M. spinosum, and M. latifolium) and grassland species (including M. zeyheri, M. speciosum, M. sessiliflorum, and M. pretoriense). The genus comprises around 18 accepted species, all transferred to Macledium from Dicoma and other genera by the botanist S. Ortiz, with basionyms authored by Linnaeus, De Candolle, Harvey, Sonder, and others.
Distribution
Macledium is distributed largely across tropical and southern Africa. Within southern Africa, species fall informally into two groups: Cape species (e.g. M. spinosum, M. relhanioides) and grassland species (e.g. M. zeyheri, M. speciosum).
Taxonomy Notes
Macledium was segregated from the genus Dicoma (family Asteraceae) and is distinguished from it by a large number of characters relating to the morphology and anatomy of phyllaries, corolla, anthers, style, cypsela, and testa. The species were transferred to Macledium by S. Ortiz, retaining their original basionyms from authors including Linnaeus (M. spinosum), De Candolle (M. speciosum), and Sonder (M. zeyheri).
