The Order _Cruciferæ_ is well represented by the wayside and on waste ground during the spring months, and the reader will do well to note the general characters of the flowers of this order (p. 17), unless already acquainted with them, before attempting to identify the species here described. Our first example--the Shepherd's Purse (_Capsella Bursa-pastoris_) is a well-known weed, often troublesome in our gardens, and may be seen in bloom from February to October. It is an erect herb, from six to eighteen inches high, which may be identified at once by reference to our illustration. The small white flowers are in lengthening racemes, and are often made less conspicuous by the conversion of the four petals into stamens. This weed is easily distinguished from all the other plants of the order by the form of the fruit, which is triangular and inversely heart-shaped. When ripe, it splits into two boat-shaped, keeled valves, which separate from a central membrane to which the seeds are attached. [Illustration: THE SHEPHERD'S PURSE.] The Common Scurvy Grass (_Cochlearia officinalis_) is to be found chiefly on the sea shore, but it often extends for miles inland, especially along the banks of the estuaries of rivers. It is a smooth, succulent plant, from four to eight inches high. The little white flowers have spreading petals, and are arranged in a short raceme; and the fruit is globular or oval, nearly a quarter of an inch long, pointed at the top, with several seeds in each cell. This plant commences to flower in May, and continues in bloom until August. The Common Whitlow Grass (_Draba verna_) is a very small and inconspicuous plant, abundant on banks and hedgerows, bearing minute, white flowers in April and May. It has a cluster of narrow, toothed, hairy, radical leaves, from a quarter to half an inch long, that spread horizontally close to the ground; and a leafless stem, from one to four inches long, bearing a raceme of flowers on slender pedicels. The petals of the flowers are deeply notched; and the fruits are oblong, about a quarter of an inch long and half that width, containing many seeds. [Illustration: THE SCURVY GRASS.] [Illustration: THE COMMON WHITLOW GRASS.] Two species of Winter Cress (genus _Barbarea_) are common in waste land--the Common Winter Cress or Yellow Rocket (_B. vulgaris_), and the Early Winter Cress or American Cress (_B. præcox_). The former is an erect plant, from one to two feet high, with numerous, small, yellow flowers in a loose raceme, blooming from May to August. The radical leaves are pinnately divided, with a large, rounded, terminal lobe, and side lobes becoming smaller towards the base; and the upper leaves are oval and irregularly toothed. All the leaves are smooth and glossy, and of a deep green colour. The fruits are short, and thicker than the pedicels. A double variety of this flower is commonly cultivated in flower gardens. [Illustration: THE YELLOW ROCKET.]