Ontogenetical and histochemical studies on the translator apparatus in Calotropis procera R. Br. I. The retinaculum

Translator apparatus consists of 2 parts--the corpusculum, which is attached to the margin of the stigmatic head between the anthers, and a pair of arms by which the corpusculum is attached to the pollinia of the adjacent anther halves. Retinaculum spans the lateral blade of the corpusculum to the acellular beak of the pollinium. Ontogenetically, it is the secretory product of the stigma along the secondary stigmatic groove. Histochemically, it is composed of lipid, lignin, cutin and a little amount of proteins. Retinaculum, like corpusculum, is stigmatic in origin, but differs histochemically from the latter being composed mainly of lipo-protein complex and lacking phenolic compounds.