Ballistochory in the herbaceous bamboo genus Reitzia (Poaceae, Bambusoideae, Olyreae): the second report of this dispersal syndrome in grasses

Seed dispersal is essential for the success of plants, allowing them to find advantageous areas to inhabit while avoiding inbreeding. Although predominantly anemochoric, grasses (Poaceae) have evolved other ways to disperse their diaspores, such as zoochory and also ballistochory (forcible dispersal), which is considered rare within this family. To date, ballistochory in grasses is only known for the sister genera Raddia and Sucrea , Neotropical herbaceous bamboos (tribe Olyreae). In this study, this dispersal syndrome is confirmed for Reitzia , a monospecific herbaceous bamboo genus and member of the Piresia clade, which is restricted to the Atlantic forest in southeastern and southern Brazil. We hypothesize that the pedicel of the pistillate spikelet, more than the glumes, may be responsible for the ballistic movement. We also provide an updated conservation assessment and a distribution map for the genus.