The plants are
graceful, with light, spreading, pinnate (resembling a feather; having parts or branches arranged on each side of a common axis) foliage, presenting an almost feathery appearance from a distance. The leaflets (like those of the False Acacia) hang down during the night on
each side of the midrib, though they do not meet beneath it. From the axils of the leaves spring racemes or spikes of papilionaceous (bilaterally symmetrical corolla somewhat resembling a butterfly) small pale-blue, violet, yellowish-white or purplish flowers, followed by small pods somewhat resembling a partly-grown pea pod in form.
The underground system, as in
so many Leguminosae, is double, the one part consisting of a vertical or tap root, often with several branches penetrating to a depth of 3 or 4 feet, the other of horizontal rhizomes, or stolons, thrown off from the root below the surface of the ground, which attain a length of many feet. These runners are furnished with leaf buds and throw up stems in their second year. The perennial downward-running roots as well as the long horizontal stolons are equally preserved for use.
Liquorice grows best on sandy soil near streams, usually not being found in the wild condition more than 50 yards from water. It will not flourish on clay and prefers the rich, fine soil of bottom lands in river valleys, where there is an abundance of moisture during the growing period, but where the ground bakes hard during the hot, late summer months, when the dry heat is very
favourable for the formation of the sweet constituents.
The plant succeeds most in a warm climate; not only can it not endure severe freezing, but cool weather interferes with the formation of its useful juice and renders it woody. It has been found that a climate particularly favourable to the production of the orange is favourable to that of Liquorice.
Owing to the depth to which the root penetrates and its ready propagation from detached pieces, the plant is a most persistent weed in cultivated grounds where it is indigenous and exceedingly difficult of remove by the roots. It is very healthy and robust and very little subject to disease, at the same time successfully occupying the ground to the exclusion of other plants. For this
reason, the continuation of the natural supply may be considered as assured, though it is liable to suffer severe reduction from over-collection.