Spur. 1. A pouch-like appendage to perianth leaves, connected with the secretion of nectar. In Tropaeolum the spur is mainly formed from one sepal, as also in Pelargonium, in which it is adherent. In Biscutel1a, a genus of Cruciferae, two sepals are spurred; in Viola, one petal; in Epimedium grandiflorum, all four; and in the Columbines, all five petals. In most spurs the nectar is excreted by the inner surface and received in the ponch; in Viola, the secretion is performed by the two tail-like appendages of the stamens; and in orchids, which were in consequence mistakenly termed by Sprengel "sham nectar-producers," it takes place within the tissues of the petalline spur, so that the insect-visitor has to bore for it. The length of a spur is in relation to that of the proboscis of the insect-visitor. That of the Madagascar orchid, Angraecum sesquipedale, is 9 inches in length.
2. An instrument for goading the flanks of a horse, worn on the rider's heel, furnished up to early mediaeval times with a single point, and subsequently with a rowel (or revolving ring armed with three or more radiating points). Spurs were used by the Romans as early as 200 B.C. They were named after, and perhaps copied from, the horny claw-like outgrowth (from the side of the metatarsus) on the foot of many birds. They are attributes of knighthood; so that "to win one's spurs" means primarily to gain the honour of knighthood, and then to make oneself a reputation. In history "The Battle of the Spurs" was the bloodless rout of the French knights by Henry VIII. near Guinegate, in the north of France, 1514. The term is applied to sundry subordinate lateral offsets, and used metaphorically for a momentary stimulus or impulse. In botany a spur is a calcar or hollow formation projecting from a flower, as from the corolla of the violet and from the calyx of the nasturtium.