Scanning electron microscopic investigation of the glandular hairs of Eremostachys superba flowers

Abstract

Scanning electron microscopic investigation of the secretory glandular hairs occurring on the inner wall of corolla tube of the flower of Eremostachys superba Royle ex Benth. (Labiatae) was carried out. Two main types of glandular hairs were found (a) peltate hairs, with a basal cell, and (b) capitate hairs, with a basal cell, a stalk cell, a neck cell and a globose, unicellular head. Further, based on their structural differences, three kinds of peltate hairs and two kinds of capitate hairs were observed. The frequency of occurrence of the peltate hairs was three times higher than that of the capitate hairs. Cuticle rupture was observed to be the mechanism of discharge of the secretory substances. The findings are discussed in relation to the pollination mechanism operating in the species.