Morphology of Heliotropium (Boraginaceae) dispersal units

In flowers of Heliotropium s.l. the primary carpel tips are overtopped by commissural outgrowths. Therefore the stylar cleft mimics a lateral orientation of the carpels. In species in which the fruit splits into four diaspores the separation tissues run through both the median and the transverse fruit planes. In species where only two two-seeded nutlets are developed the fruit splits within the false septa and each half is composed of parts of both carpels (“syn-mericarpids”).