| 1 | Lower glume separated by an internode; upper lemma glabrous at the apex . | |
| 2 | Culm sheaths thin; glumes and lemma densely glaucous, sparsely puberulous or nearly glabrous. | |
| 3 | The structures of papilla of lemma in 21 species of Oryza and 2 species of Leersia were observed by scanning electron microscopy. | |
| 4 | This rare race differs from the others by having glumes and lemmas narrowly acuminate , the glumes subequal to the lowest lemma. | |
| 5 | The REP1 gene is only expressed in palea primordium during early flower development, but during later floral stages is radially dispersed in stamens and the vascular bundles of the lemma and palea. |