Lemma (botany)

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

Lemma is a phytomorphological term used in botany referring to a part of the spikelet of grasses (Poaceae). It is the lowermost of two chaff-like bracts enclosing the grass floret. It often bears a long bristle called an awn, and may be similar in form to the glumes - chaffy bracts at the base of each spikelet. It is usually interpreted as a bract but it has also been interpreted as one remnant (the abaxial) of the three members of outer perianth whorl (the palea may represent the other two members, having been joined together).

A lemma's 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.