The nature of ‘bracteoles’ in Atripliceae

The tribe Atripliceae (Chenopodiaceae) has been characterized by having perianthless female flowers surrounded by two accrescent bracts/bracteoles. Flores-Olvera et al conduct a floral ontogenetic study using LM and SEM for nine species of Atriplex, Chenopodium, Dysphania and Spinacia and show that all flowers develop a perianth. The so-called bracts/bracteoles are actually modified perianth members; moreover, a large flexibility in the sex determination of the flowers exists, with flowers within some species varying from bisexual, functionally unisexual to strictly unisexual.