It usually rises in tufts with bare spaces between, or the intervals are occupied by creeping plants, which, having their roots buried far beneath the soil, feel little the effects of the scorching sun.

The number of these which have tuberous roots is very great; and their structure is intended to supply nutriment and moisture, when, during the long droughts, they can be obtained nowhere else.

Here we have an example of a plant, not generally tuber-bearing, becoming so under circumstances where that appendage is necessary to act as a reservoir for preserving its life; and the same thing occurs in Angola to a species of grape-bearing vine, which is so furnished for the same purpose.

The plant to which I at present refer is one of the cucurbitaceae, which bears a small, scarlet-colored, eatable cucumber.

Another plant, named Leroshua, is a blessing to the inhabitants of the Desert.