An African dirk with its sheath.

Dirk with Sheath

An African dirk with its sheath.

<i>Lolium perenne</i>. A sheath, in botany is "the part of an expanded organ that is rolled around a stem or other body, forming a tube, as in the lower part of the leaves of grasses..." &mdash;Whitney, 1889 
<p>This illustration show a single leaf of ryegrass in its sheath.

Ryegrass Leaf with Sheath

Lolium perenne. A sheath, in botany is "the part of an expanded organ that is rolled around a stem or…