Inflorescence development in Abildgaardieae(Cyperaceae, Cyperoideae)

REUTEMANN, A. G.; VEGETTI, A. C.; POZNER, R.

FLORA

ELSEVIER GMBH

Año: 2015 vol. 210 p. 3 - 12

0367-2530

Inflorescences in Cyperaceae are a source of characters with significant systematic value; however, thestructure and primary homologies pose a challenge to their interpretation. The relationships among mem-bers of Abildgaardieae are not clear due to the absence of a phylogeny with strong support, comprisinga representative number of species. Establishing correct primary homologies of inflorescences withinAbildgaardieae might help to clarify the relationships among its members, as well as to find synapo-morphies for the most important clades. Variations in the mature inflorescences within Abildgaardieaehave been related to their ?shape? and ?structure?, and preliminary phylogenetic studies in species ofBulbostylis have shown that inflorescence structure traits are phylogenetically informative, but this is nottrue for the mere shape. While similar structures in the adult inflorescences of the members of differ-ent clades within Abildgaardieae might be considered homologous, it must be ascertained whether suchsimilar structures share the same developmental process or have different developmental patterns. Bystudying the development of inflorescences in selected species of Abildgaardieae using SEM, we wereable to show that inflorescences with homologous structures share a similar developmental process and,therefore, the adult structure of inflorescences may be relied on for establishing correct primary mor-phological homologies in this plant group. Most structural variations of inflorescences in Abildgaardieaedepend on the degree of development of processes shared by the studied species. While phyllotaxisin the main axis of Cyperus may be modified during inflorescence development after primordial incep-tion, variations in the phyllotactic patterns of leaves on vegetative shoots (=nomophylls) and of leaveson fertile shoots (=bracts or hypsophylls) within Abildgaardieae, might establish deeper differences ininflorescence structure, since they depend on changes in the shape of the apical meristem.