The sheath is often of great length, and generally completely surrounds the culm, forming a firm protection for the internode, the younger basal portion of which, including the zone of growth, remains tender for some time.
They are eminently dry-country plants (xerophytes); the narrow leaves are protected from loss of water by a thick cuticle, and have a well-developed sheath which embraces the stem and forms, with the sheaths of the other leaves of the rosette, a basin in which water collects, with fragments of rotting leaves and the like.
In it are carried, by literati and merchants, the pen-case and a roll of paper; its voluminous folds are used as pockets; by the bazaar people and villagers, porters and merchants servants, a small sheath knife is struck in it; while by farrashes, the carpet-spreader class, a large khanjar, or curved dagger, with a heavy ivory handle, is carried.
Between the two corpora cavernosa the sheath is not complete and, having a comb-like appearance, is known as the septum pectinatum.
The characteristic of this family - as represented by the prongbuck - is that the sheath of the horns is forked, and shed annually, or every few years.
This is brought about by a double commissure, of which the ventral portion is considerably thicker than the dorsal, and which, together with the brain-lobes, constitutes a ring through which both proboscis and proboscidian sheath pass.
In sedges the sheath forms a complete investment of the stem, whilst in Leaf grasses it is split on one side.
But as his chief aim consisted not in carrying out his design, but in proving to himself that he would not abandon his intention and was doing all he could to achieve it, Pierre hastily took the blunt jagged dagger in a green sheath which he had bought at the Sukharev market with the pistol, and hid it under his waistcoat.
The firs are distinguished from the pines and larches by having their needle-like leaves placed singly on the shoots, instead of growing in clusters from a sheath on a dwarf branch.
Most interesting of these is the dagger or sword, always very short, save in the latest graves, and distinguished by a heart-shaped guard marking the juncture of hilt and blade; its sheath is also characteristic, having a triangular projection on one side and usually a separate chape: these peculiar forms were necessitated by a special way of hanging the dagger from two straps that it might not interfere with a rider's movements.