Root anatomy of grasses and clovers

Abstract

Summary Comparisons are made of the anatomy of the mature parts of roots of the grasses Lolium perenne , Dactylis glomerata , Glyceria fluitans , and Alopecurus pratensis . Noteworthy features include a well‐marked exodermis and a subjacent layer of sclerenchyma in Glyceria ; the greater lignification of the Dactylis root as compared with Lolium ; the greater total cross‐sectional area of metaxylem vessels in Dactylis compared with the other three species; and the degree of development of lysigenous lacunae, which was least in Dactylis and greatest in Glyceria and Alopecurus . Structural similarities are noted between the roots of Glyceria and Oryza (rice). The structure of the cortex, particularly the development of lysigenous lacunae, is discussed in relation to habitat of the plant, aeration of the root, and absorption of water and nutrients. The anatomy of mature parts of roots of the legumes Trifolium repens , T. pratense , and Lotus uliginosus , and of the mature Lotus nodule are briefly described. T. repens and T. pratense had considerable secondary growth, a periderm developed in the pericycle, and the cortex and endodermis were sloughed off. Lotus had less secondary growth and retained its cortex for longer.