Inflorescence typology of Zizaniopsis bonariensis and Z. villanensis (Poaceae, Oryzeae)

Abstract

Inflorescences of Zizaniopsis bonariensis (Balansa & Poitr.) Speg. and Z. villanensis Quarín were typologically studied. The inflorescences of these species are polytelic; a main florescence and a paracladial zone were noticed. The last one consists of a reduced subzone of short paraclades and a well developed subzone of long paraclades. There is also an important variation in the sexuality of the florescences. In Z. bonariensis the main florescence and the coflorescences of the paraclades of higher order are represented by a pistillate spikelet whereas the coflorescences from lower order paraclades are staminate spikelets. A high concentration of staminate florescences at the proximal regions of the inflorescence is also seen. Zizaniopsis villanensis has a predominance of staminate florescences at a distal position of the inflorescence, with the pistillate ones at the base of the inflorescence.