RHIZOMATOUS LOTUS-CORNICULATUS L .2. MORPHOLOGY AND ANATOMY OF RHIZOMES

Birdsfoot trefoil (Lotus corniculatus L.) is a valuable forage legume. Rhizomatous L. corniculatus germplasm from Morocco was recently disco vered. Increased persistence may result from rhizomatous habit, becaus e new plants vegetatively generated by rhizomes could replace diseased or dead plants. Rhizome morphology in L. corniculatus from Morocco is unique because taxonomic descriptions for L. corniculatus do not incl ude the presence of rhizomes. The objectives of this study are to desc ribe and compare morphology and anatomy of subterranean lateral shoots (rhizomes) and aerial shoots (stems) of L. corniculatus. Rhizomes of Moroccan L. corniculatus are initiated from axillary buds on basal por tions of shoots. The rhizome consists of nodes and internodes, with bu ds, scale leaves, and adventitious roots occurring at each node. Anato mically, the rhizome of L. corniculatus has a large cortex, small pith , and six to seven primary vascular bundles. Na endodermis exists in t he cortex, and parenchyma cells contain starch. In contrast, the aeria l shoot of L. corniculatus has a small cortex, large pith, and nine to 10 primary vascular bundles. An endodermoid layer is peripheral to th e concentric ring of vascular bundles of the aerial shoot, and parench yma cells in the cortex contain chloroplasts. Morphological and anatom ical differences between L. corniculatus rhizomes and aerial shoots ar e distinguishable.