ANTIRRHPNUM, a genus of plants belonging to the natural order Scrophulariacew. This genus is the type of a section of the order to which also the genera Linaria, Anarrhinum, Maurandia, Galresia, Lophospermum, and Illiodochiton belong. It is characterised by a 5-parted oblique calyx ; a personate corolla, gibbous at the base, but with no distinct spur; the lobes of the upper lip erect, those of the jower spreading, 3-fid, with the middle segment smallest, and a bearded palate which closes the mouth ; the capsule 2-celled, opening by two or three pores at the top ; seeds oblong, minute, with black testa. The species are annual or perennial, rarely shrubby. The leaves are fimther-veined, and entire, opposite below, and usually alternate above. Two of the species are indigenous to Great Britain. All of them produce showy flowers, and are much cultivated in gardens. Their medicinal properties are not very active.
A. snafus, Great or Common Snapdragon, has lanceolate, opposite or alternate glabrous leaves, racemose flowers, ovate obtuse sepals, much shorter than the corolla, and the upper lip bifid. This plant attains a height of one or two feet, and has purplish-red or white flowers. It is found in Great Britain on old walls and chalk cliffs, especially in the neighbourhood of London, but it is undoubtedly a naturalised plant, being truly indigenous in the south of Europe and the north of Africa. In gardens a variety is often seen with double
flowers. The leaves are bitter and slightly stimulant.
A. Orontium, Orontium Snapdragon, or Calves' Snout, has linear lanceolate opposite or alternate leaves ; the flowers loosely spiked, distant ; the sepals linear and longer than the corolla. This plant appears to be truly indigenous in England and Ireland, where it occurs in dry sandy and gravelly soils. It is also a native throughout Europe, in the islands of the Mediterranean, and the north of Africa. It has been found in Virginia, but it has been probably introduced. Its leaves as well as those of other species have been used as cataplasms in indolent tumors.
Don enumerates twelve other species, many of which have been introduced into our gardens. They are pretty border-flowers, and adapted for rock-work. They are easily cultivated ; the perennial species may be increased by cuttings, and the annual raised by seeds. The species from subtropical districts will however require a frame or the greenhouse in the winter.
(Babington, Manual of British Botany; Don, Gardener's Dictionary.)