The objective of this study was to investigate ryegrass seedling characteristics that, by themselves, or combined with presently known characters, could improve varietal identification tests. Thirteen characters were studied on 30 varieties of Lolium multiflorum Lam., L. perenne L., L. rigidum Gaud, and L. hybridum Hausskn., including leaf size and area, epidermal characteristics, structural elements, and leaf blade vernation. Mean differences among species occurred in the following characteristics: Lolium multiflorum. and L. perenne: leaf width, leaf length, leaf area, minor and major vascular bundles, lower and upper sclerenchyma fiber groups, hair density, number of vascular bundles, and leaf blade vernation, Lolium multiflorum and L. hybridum; leaf width, leaf length, leaf area and leaf vernation. Lolium perenne and L. hybridum: leaf width, leaf length, leaf area, and total of sclerenchyma fiber groups, and leaf vernation. Lolium perenne and L. rigidum: leaf width, leaf length, leaf area, and leaf vernation. Lolium multiflorum and L. rigidum: leaf blade vernation. Lolium hybridum and L. rigidum: leaf blade vernation. Tetraploids and diploids were significantly different on the average, within their respective species, as follows: Lolium multiflorum: leaf width, leaf length, leaf area, stomata density. Lolium perenne: leaf width, leaf length, leaf area, stomata density. Lolium hybridum: stomata density, and number of major vascular bundles. Some significant differences among varieties within species and ploidy levels were observed in the following characteristics: Lolium multiflorum tetraploids: leaf width, leaf length, leaf area, minor vascular bundles. Lolium multiflorum diploids: leaf width, leaf length, leaf area, minor vascular bundles, total vascular bundles. Lolium perenne tetraploids: leaf area. Lolium perenne diploids: leaf length, leaf area, minor vascular bundles. Although varietal means differed for many of the characters, individual plants could not be identified on the basis of a single character. An illustration was prepared to show how a combination of morphological characters might be used in varietal identification. With a table of varietal means for nine characters, only two (Jolanda and Tetrone--both tetraploids of L. multiflorum) of the 30 varieties studied were indistinguishable. The leaf blade vernation of Wimmera (L. rigidum) and. Tetrelite (L. hybridum) appeared to be intermediate between that of L. multiflorum and L. perenne. The vernation was folded from the midrib, like in L. perenne, while the edges of the leaf were inrolled and overlapping, somewhat like L. multiflorum. This type of vernation is being called semi-rolled, to conveniently distinguish from "rolled" and "folded"
