Graniferous Tracheary Elements in the Haustorium of Osyris arborea Wall. (Santalaceae)

In the haustorium of Osyris arborea (a non-host specific roothemi-parasite) a distinct interrupted zone is present abovethe vascular core. The majority of the xylem elements in thevascular core are perforated. Graniferous tracheary elementsin this species are recorded for the first time. Cytochemicaltests showed the granules to be proteinaceous. The suggestedfunction of graniferous tracheary elements in the regulationof pressure and flow of sap is discussed. Osyris arborea, root hemi-parasite, Santalaceae, haustorium, graniferous tracheary elements, protein granules