Resin production and glandular hairs in Beyeria viscosa (Labill.) Miq. (Euphorbiaceae)

Abstract

Leaves of Beyeria viscosa secrete resin with components related to the gibberellins. Two-celled glandular hairs are well developed on the young leaf, and are coated with a thick layer of resin, which makes up almost half the dry weight associated with the young leaf. Plastids of the glandular hairs have poorly developed internal membranes but are enveloped in tubules, apparently derived from endoplasmic reticulum. As the leaf expands, resin secretion ceases; the resin layer is torn apart and is seen largely as caps over the hairs. Resin accounts for some 20% of the dry weight associated with the mature leaf. Resin components also accumulate in the epidermis and certain mesophyll cells. No significant changes take place in the chemistry of the secreted components as the leaves mature, as seen by thin-layer chromatography.