They climb by means of tendrils, which are stipular structures arising from the leaf-sheath.
In wheat, barley and most of the British native grasses they are a development, not of the culm, but of the base of the leaf-sheath.
The remarkable ovoid involucre of Coix, which becomes of stony hardness, white and polished (then known as " Job's tears," q.v.), is also a modified bract or leaf-sheath.
The leaves of successive whorls alternate with one another, and this applies also to the branches which arise in the axil of the leaf sheath.
A, Longitudinal section of the rhizome, including a node and portions of the adjoining internodes; k, septum between the two internodal cavities, hh; gg, vascular bundles; 1, vallecular canal; s, leaf-sheath.
