Palea (botany)

Palea, in botany, refers to one of the bract-like organs of the grasses spikelet (Poaceae). It is the uppermost of the two chaff-like bracts that enclose the grass floret (the other being the lemma). It is often cleft at the tip, implying that it may be a double structure derived from the union of two separate organs. This has led to suggestions that it may be what remains of the grass sepals (outer perianth whorl): specifically the two adaxial members of the three membered whorl typical of monocots. The third member may be absent or it may be represented by the lemma, according to different botanical interpretations.

The perianth interpretation of palea is supported by the expression of MADS-box genes in this organ during development, as is the case in sepals of eudicot plants [Prasad, K, et al. (2005) OsMADS1, a rice MADS-box factor, controls differentiation of specific cell types in the lemma and palea and is an early-acting regulator of inner floral organs. The Plant Journal 43, 915–928] .

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