Autochory

Abstract

Autochorous plants are equipped with an autonomous mechanism involved in seed dispersal. Some of these mechanisms provide for telechoric dispersal, whereas others prevent dispersal and are antitelechoric (Fahn and Werker 1972). Ballistic dispersal, a form of telechoric autochory, occurs when the diaspore is propelled explosively, by a fruit that opens suddenly or by a triplever (Willson et al. 1990). It may be due to tension in dead hygroscopic tissues or living tissues (Van der Pijl 1982). Another form of telechoric autochory is the hygroscopic movements of organs (e. g. bristles, involucral bracts, calyxes, awns) which cause the whole diaspore to move on the ground and propel the diaspore in a definite direction (McCann 1959). Trypanospermic or boring fruits are examples of antitelechoric dispersal mechanisms and are equipped with a hygroscopic drilling apparatus or with a sharply pointed tip which enables them to penetrate the soil.