PINUS, in botany, a genus of the monoclea monadelphia class. The calix of the male consists of four leaves; it has no corolla; the stamens are numerous, with naked anther. The calix of the female is a strobilus, containing two flowers; it has one pistillum; and the nut is embraced by a membranaceous wing. There are 12 species, three of them natives of Britain, viz. the sylvestris, or Scotch fir; the picea, or yellow-leaved fir; and the abies, or common fir.