On some chalky heaths the True Sweet-briar (_Rosa rubiginosa_--order _Rosaceæ_) is a common shrub, growing from three to six feet high, and flowering during June and July. It is an erect and compact bush, with numerous prickles of varying shapes--the larger ones being hooked, while the smaller are straight and very unequal. The leaves are compound and stipuled, and the leaflets are rounded at the base, downy, and doubly serrate. The flowers often grow singly, but more commonly from two to four together; they are of a deep rose colour, and the persistent sepals are pinnately divided. The fruit is at first pear-shaped, but afterwards becomes almost globular, and turns red when ripe. [Illustration: THE SALAD BURNET.] In similar situations we may find the Lesser Burnet or Salad Burnet (_Poterium Sanguisorba_) of the same order. This plant is so different in general appearance from the majority of the Rose family that the amateur would hardly associate it with the others. The flowers are small, and collected together in dense, purple cymes on the top of long, angular stalks. They have no petals, and the four overlapping sepals are usually deciduous. The stamens, five to thirty in number, are pendulous on long, slender filaments; and the upper flowers display their crimson stigmas before the lower ones produce their stamens. The stem is erect, from six to eighteen inches in height; and the pinnate leaves have many small, sessile, oblong leaflets with coarsely-serrate edges. This plant flowers during June, July, and August. [Illustration: THE FIELD GENTIAN.] The Bedstraw Family (order _Rubiaceæ_) is represented on the chalk by the Rough-fruited Corn Bedstraw (_Galium tricorne_), which is common in fields. It is a spreading plant, with procumbent stems, one to three feet long; and small, long, narrow leaves, rough with recurved prickles, arranged in whorls of from six to eight. The flowers are small and white, grouped in little cymes of three. The fruit is comparatively large, and granulated, but not bristly, and it droops by the bending of the pedicel. The plant flowers from June to October. The Red Spur Valerian (_Centranthus ruber_--order _Valerianaceæ_) is a glaucous, leafy plant (see Plate VIII), sometimes growing to a height of two feet or more, often to be seen in chalk-pits and limestone quarries, and frequently on old walls. It is not indigenous, but is cultivated largely as a garden flower, and has now become naturalised. Its corolla, which is sometimes white, has five unequal lobes, a long, flattened tube, and a slender spur. The plant flowers from June to September.