Notes on Some Grasses XIX

Systematic Significance of Microhairs of Lodicule Epidermis

Abstract

Lodicules of 288 species of grasses representing 146 genera were examined. The presence of microhairs on the lodicule epidermis was demonstrated in 55 species of 27 genera. The microhairs are very frequent in the Bambusoideae and the tribe Danthonieae of the Arundinoideae and, on the other hand, rare in the Oryzoideae, Eragrostoideae, Panicoideae and most tribes of the Arundinoideae. The hairs are usually rod-like and 40-90μ in length. Most of them are bicellular, but some with three or more cells occur along with two-celled hairs in several species of the tribes Bambuseae, Arundinarieae and Danthonieae. In the Festucoideae, no species were found to have lodicule microhairs. It seems evident that the Festucoideae are completely lacking in microhairs, not only on the leaves but also on the lodicules and other organs which arise in a foliar manner. Microhairs are abundant per lodicule in the great majority of species of the Bambusoideae, but are less common on lodicules of the other subfamilies. Bambusoid lodicules are leafy in shape and vascularization, and the presence of numerous microhairs may also be an indication of their primitive nature.