A very common shrub which inhabits marshes, the banks of rivers and the fringes of lakes, in fact, any low-lying, inundated ground, forming dense, impenetrable thickets, often of large extent. On the banks of rivers it is frequently associated with a species of _Salix_ or willow. It has numerous stems and long erect or drooping shoots, 10 to 12 feet in length. The whole plant is covered with hairs. =The Thorns= on the stems are in three’s, below each leaf, one thorn directly under the leaf, with a pair a little higher up on either side. The thorns on the stems are all the same size and shape, but those on the leaves differ as described below. =The Leaves= are 3-5 inches long with 6-8 pairs of pinnae, bearing up to 40 pairs of long, narrow leaflets. The leaf is sensitive and folds up tight in the evening, the leaflets falling back under the mid-rib. On the upper side, between each pair of leaflets, is a short, slender and very sharp thorn, pointed well forward, and between the lower 4 or 5 pairs is a pair of sharp thorns with broad bases in the same plane as the leaflets. These thorns are absent in the upper part of the leaf. The young leaf is hairy. =The Flowers= are in spherical heads about ½ inch in diameter, either white or mauve. Each minute flower has a calyx of 4 sepals, 8 stamens with white or mauve filaments and white anthers, and a long pistil. =The Fruits= are pods, 2-2½ inches long, ½ inch wide and ⅛ inch thick, slightly curved. They are covered with erect, bristly hairs whose tips curve forward. On the green pod these hairs are golden brown; on the ripe pod they are unpleasantly penetrating. The pod splits transversely into 15-20 segments, each containing a small bean. The outer rim of the pod remains intact, the sections dropping out in the same manner as those of _Entada sudanica_. =Uses.=—It is used as a fence round farms for protection against grazing, and in places where there is an acute shortage of fuel demands a price in the markets. [Illustration] =MITRAGYNE AFRICANA= Korth.—_Giyeya_. _Giyaiya_. RUBIACEAE. A large tree which inhabits “fadammas,” “tabkis” or annually inundated areas. It has several erect, straight stems ascending to a height of 60 feet in large specimens and the foliage reaches almost to ground level. From the branches, especially noticeable when one of these is horizontally inclined, are a number of slender erect shoots, like those of pollarded willow. The crown is the same width throughout with a narrowed or pointed top. The tree coppices very well and would provide a rotation crop if properly worked. It will not stand drought and a succession of dry years will kill the tree, subsequent wet years only serving to rot the dead trees. This is of frequent occurrence in the farthest north. =The Bark= is light brown or grey and smooth, a few scales showing on the lower part of the stem in season. The slash is light brown, rapidly darkening.