an elongated, cylindrical structure that encloses
younger parts of the shoot.
Its major function is to protect younger shoots
inside of it and to support the whole plant, which explains why there are
very few chloroplasts found in the sheath mesophyll.
Leaf
Blade
flat, elongated, and ribbon like--the "leafy"
part of the leaf
it is usually longer than the sheath
its major function is to perform photosynthesis
Collar
a white band at the junction of the blade
and the sheath
Here
is a close up of the collar.
Ligule
triangular, papery scale located inside the
blade
it looks like a continuation of the sheath
it is absent in some species
Auricle
a pair of hairy, sickle-shaped appendages
located in the junction of the collar and the sheath
it is absent in some species
This picture beautifully shows
a pair
of auricles on a young rice leaf.