Leaf Sheaths

The leaf sheath surrounds the inter node like a tube, but it is not a closed tube. The function of the ligu is probably to facilitate the shedding of water which may run down the leaf and thus lessen the danger of rotting of the stem. In bamboos and some species of s there occurs a short petiole or stalk between the leaf blade and the sheath. As in aresa sadiva, such outgrowths are called oracles or auricular outgrowths.