The structure and function of trichomes in the leaf of Salvia repens Burch. Ex Benth

The anatomical investigation using scanning and transmission electron microscopy revealed that Salvia repens is characterized by both non-glandular and glandular trichomes. It has been demonstrated that both trichomes appeared to originate from epidermal cells of the leaf, stem and vegetative area through a series of periclinal and anticlinal division. Non-glandular trichomes were composed of uniseriate cells. The terminal cells of the non-glandular trichomes were the first cells to mature. A progressive maturity resulted in continuous death of the uniseriate cells progressing towards the basipetal position. The dead cells resembled fibrous like clothing threads which were covering the epidermis. Structurally, these fibrous ends were similar in composition to the components of the suberized cell wall. The glandular trichomes were multicellular and uniseriated. Their shape ranged from oval to club, and they were composed of a basal cell, stalk cell and a three to four sided glandular head. The orientation of these glandular trichomes was not uniform, however, a different orientation of glandular trichomes was observed in the leaves and stem. The micrograph of these glandular trichomes showed that they started as outgrowth of the epidermis cells, and subsequent periclinal division followed by anticlinal division, giving rise to a trichome with a basal epidermal cell, stalk cell and three to four celled secretory head. At maturity the glandular trichome gland cells contained a distended cuticular sac due to the accumulation of the essential oil.   Key words: Non-glandular, glandular trichomes in Salvia repens.