Lodicules

Lodicules are small, scale-like floral organs found in the flowers of grasses (Poaceae) and some related monocots. They lie at the base of the floret, inside the lemma and palea, and are typically two in number per floret, though variation exists among taxa. Lodicules are sterile and represent highly reduced perianth elements in grasses.

Development and anatomy: Lodicules arise from the floral meristem during spikelet development. They are usually thin and membranous, sometimes leaf-like in appearance, and may be green, yellow, or reddish. When the flower is about to open (anthesis), the lodicules swell by water uptake and exert pressure that separates the lemma and palea, creating an opening through which pollen is released and pollination occurs.

Function and significance: The main function of lodicules is to facilitate the opening of the floret. They act as a hinge or swelling pad that allows the protective bracts to part without damaging the reproductive organs. Lodicules are a characteristic feature of many grasses and can be used in taxonomic identification. They also provide a morphological clue in paleobotany for recognizing fossil grass spikelets.

Variability: Some taxa show reduced or inconspicuous lodicules, and in rare cases the two organs may be fused or difficult to distinguish.