Similar to rudimentary glumes, empty glumes have been considered as metamorphic bract leaves (Chase, 1968; Bell, 1991; Takeoka et al., 1993). The alternative hypothesis is that empty glumes are remnants of two lower reduced florets that lost all their inner floral organs.

What are called glumes?

In botany, a glume is a bract (leaf-like structure) below a spikelet in the inflorescence (flower cluster) of grasses (Poaceae) or the flowers of sedges (Cyperaceae). ... Glumes may be similar in form to the lemmas, the bracts at the base of each floret.

How many empty glumes are there in rice?

The rice spikelet is thought to have three florets[3,5], which are subtended by two tiny glumes (rudimentary glumes) (Fig. 2). The uppermost floret is bisexual and fertile, whereas the lower two florets are strongly reduced and sterile.