Spikelet

A spikelet is a small unit of the inflorescence of a grass, containing one or more florets on a short axis. Usually a pair of glumes occurs at the base, and each floret is associated with a lemma and palea.^[ref]

This hierarchy matters when counting. An apparent “grain-bearing unit” can be a spikelet with several flowers, so counting spikelets is not generally the same as counting flowers or mature seeds. To inspect one, separate the basal glumes and then examine the individual florets inside. The nested organization links a recognizable cereal head to the reproductive structures of other angiosperms.

In a grass floret, the palea is the upper of the two enclosing bracts; the lower is the lemma.^[ref]

During dissection, open the basal glumes of the spikelet, then separate each floret's lemma and palea. This follows two different levels of the inflorescence.

The lemma is the lower of the two bracts enclosing a grass floret; the upper is the palea.^[ref]

In a schematic three-floret spikelet, each floret can have its own lemma and palea, within the basal glumes. Counting each lemma and counting each glume therefore answer different structural questions.

A glume is one of the usually paired bracts at the base of a grass spikelet. Individual florets inside have their associated lemma and palea.^[ref]

Inspect from outside inward: locate the glumes, open the spikelet, then examine its florets. A hypothetical three-floret spikelet can have two basal glumes: the number of enclosing bracts need not equal the number of flowers.