Reproductive traits related to anemophily and insect visitors in two species of Poaceae from the Brazilian Atlantic rainforest

Abstract

The floral biologies of two grass species occurring in the Brazilian Atlantic Forest, Bahia were examined to determine whether the morphological characteristics of their synflorescences, spikelets, and pollen grains were compatible with those expected for anemophily, and whether there was any biotic assistance in their pollination. Both Lasiacis ligulata Hitchc. & Chase (Panicoideae) and Olyra latifolia L. (Bambusoideae) have herbaceous habits, paniculate synflorescences, bifloral and unifloral spikelets, inconspicuous flowers, with pollen offered as a resource. L. ligulata is a homogamous species, while O. latifolia is protogynous. Their pollens are only available in the morning; the pollen grains of L. ligulata and O. latifolia are ornamented and contain starch, but without pollenkitt or lipids. Both species are visited by flies (Cecidomyiidae), beetles (Chrysomelidae), and ants (Brachymyrmex sp.) that possibly can aid in liberating pollen grains. The present study brings new data concerning the floral biology and anemophily of herbaceous Poaceae in the Brazilian Atlantic Rainforest, suggesting the insect-assisted anemophily in L. ligulata.