Figure 2.
Diversity of structure at the sheath–blade boundary of leaves in the grass family. The ligule, or sheath extension, and the auricles are indicated. Both ligules and auricles of maize are missing in the absence of either LG1 or LG2 proteins. The ligule and auricles of maize and rice are very different. A species from each of three other grass genera is also represented. There is much variability of structure, presumably reflecting genetic polymorphism, for this region of leaf.
