Spikelet

The perianth is reduced to two scales, called lodicules,[1]: 11  that expand and contract to spread the lemma and palea; these are generally interpreted to be modified sepals.

The lemma often bears a long bristle called an awn, and may be similar in form to the glumes, which are chaffy bracts at the base of each spikelet.

The lemmas' shape, their number of veins, whether they are awned or not, and the presence or absence of hairs are particularly important characters in grass taxonomy.

The perianth interpretation of the palea is supported by the expression of MADS-box genes in this organ during development, as is the case in sepals of eudicot plants.

[3] A lodicule is the structure that consists of between one and three small scales at the base of the ovary in a grass flower that represent the corolla, believed to be a rudimentary perianth.

Parts of a single grass spikelet, consisting of two glumes, four fertile florets, with one additional central floret that may or may not be sterile