Callista is a genus established by the late Professor Don, which appears very distinct, though it also has not been generally adopted. It includes all those beautiful Cape Heaths which have a shining, glutinous, ventricose, or cylindrical corolla with a spreading limb (see _a_ in _fig._ 50), and a capitate stigma (_b_). _C. bucciniflora_ and _C. ventricosa_, are examples of this genus. [Illustration: FIG. 50.—CALLISTA BUCCINIFLORA.] The Ling or Heather, which Linnæus called _Erica vulgaris_, is now generally placed by all botanists in a separate genus called Calluna, which was established by Mr. Salisbury. The calyx of this plant is membranous, and coloured so as to resemble a corolla, and it is furnished with four bracts at the base, which resemble a calyx. The true corolla is bell-shaped, and shorter than the calyx. The stamens are inclosed, and the anthers are of the very singular form shown in _fig._ 51. The stigma is capitate, and the flowers are disposed in what is called a racemose spike. The leaves are trigonal; they are very short, and they are laid over each other like scales in four rows. The Ling is the only species in the genus. [Illustration: FIG. 51.—STAMEN OF THE LING.] SUB-TRIBE II.—ANDROMEDEÆ. The plants in this sub-tribe differ decidedly from those of the preceding division, in having ten stamens, while all the genera of heaths have only eight. The calyx is also five-cleft instead of four; and the corolla, which falls before the seeds are ripe, has a five-lobed limb. The sub-tribe is divided into twenty genera, more than half of which are perfectly distinct. [Illustration: FIG. 52.—STAMEN OF ANDROMEDA.]