Chaff is dry, scale-like plant material such as the protective seed casings of cereal grains, the scale-like parts of flowers, or finely chopped straw. Chaff cannot be digested by humans, but it may be fed to livestock, ploughed into soil, or burned.
Rice chaff
Spikelets of a hulled wheat, einkorn
Husk in botany is the outer shell or coating of a seed. In the United States, the term husk often refers to the leafy outer covering of an ear of maize (corn) as it grows on the plant. Literally, a husk or hull includes the protective outer covering of a seed, fruit, or vegetable.
Husk of Corylus colurna (Turkish Hazel), containing 7 nuts
Corn being husked in the yard of a Dungan farmer in Kyrgyzstan