Pericarp structure of Glebionis coronaria (L.) Cass. ex Spach (Asteraceae) cypselae controls water uptake during germination.(L.) Cass. ex Spach is a common Mediterranean weed producing distinctive central and peripheral dormant cypselae with a hard fruit coat, which was previously hypothesized to impose physical dormancy. Analysis of water uptake in cypselae and in naked seeds showed that it preferentially takes place at the basal end of...