This illustration shows the important morphological features of an annual bluegrass plant. The leaves are divided into two main parts: the lower portion is the sheath, which clasps around the vertical axis of the shoot; ans the upper portion is the blade, which is flattened and extends outward from the shoot. The leaves may also contain a ligule at the base of the leaf blade. In some species, extensions of the base of the leaf blade, called auricles, may exist as well. On the other side of the leaf is the collar. Lateral shoots--including tillers, rhizomes, and/or stolons--may emerge from structures at the base of the shoot. When in the reproductive stage of growth, a flowering culm may emerge that terminates in an inflorescence. Adventitious roiots also emerge from structures at the base of the shoot. This differs from the seminal roots that are produced from the embryo during germination. In some juvinile plants, both seminal and adventitious roots mat be present; however, seminal roots generally disappear within six months of germination.
