Post date: Apr 12, 2012 3:11:45 AM
The rice grain is the ripened ovary, with the lemma, palea, rachilla, sterile lemmas and the awn firmly attached to it.
Fig. 46 - Rice grain.
The rice hull includes the lemma and palea and their associated structures – the sterile lemmas, rachilla, and awn.
Fig. 47 - Rice hulls.
The dehulled rice grain is called caryopsis, commonly referred to as brown rice because of three brownish pericarp layers that envelope it. Next to the pericarp layers are the two tegmen layers and the aleurone layers.
Fig. 48 - Tagmen, pericap, and aleurone layers.
The remaining part of the grain consists of the endosperm and the embryo. The endosperm provides nourishment to the germinating embryo. The embryo lies on the belly side of the grain and is enclosed by the lemma. It is the embryonic organ of the seed.
Fig. 49 - Endosperm and embryo.
The embryo contains the plumule (embryonic leaves) and the radicle (embryonic primary root).
Fig. 50 - Plumule and radicle.