GYMNOSPERM^. 725 



Pines may conveniently be divided into 2- and 3-leaved forms on the one hand, and 

 5-leaved on the other. The former agree in possessing cones of the type shown in 

 fig. 337 ^, p. 443, in which the ends of the ovuliferous scales visible at the surface 

 of the cone are pyramidal, whilst the 5-leaved forms are without these terminal 

 pyramids. Among the 2-leaved Pines (20 species) are included the Scotch Pine 

 (P. si/lvestris, fig. 409), the Stone Pine (P. Pinea), the Mountain Pine (P. humilis 

 or montana, Plate X., and fig. 135, vol. i. ji. 549), the Corsican and Aleppo or Shore 

 Pines (P. Lancio and P. halepemsis), and many others. Of the 16 species of 3- 

 leaved Pines the majority are North American and Oriental. The Himalayan 

 P. longifolia has needles nearly half a metre long, and the Californian P. Coulteri 

 cones attaining a like leucrth. 



The 5-leaved forms include about 35 species, of which the beautiful Arolla Pine 

 (P. Cembra, fig. 410) is a European, and the Weymouth Pine (P. Strobus) a North 

 American example. 



The genus Cedrus is represented by 3 forms, the Cedar of Lebanon (C Libani), 

 common in Asia Minor, the Deodar (G. Beodara) of the Himalayas, and the Atlas 

 Cedar (C. atlantica). Some authorities regard these as but varieties of one species. 



The Larch (Larix, cf. fig. 337 \ p. 443, and fig. 354, p. 483) bears its needles, 

 which are deciduous, in tufts. The Firs which comprise the genera Abies, Picea, 

 and Tsuga, differ from the Pines, &c., in that the leaves are borne directly upon 

 the elongating branches. Abies, typified by the Silver Fir {Abies pectinata, cf. 

 fig. 177, vol. i. p. 717), has erect cones {cf. fig. 407 \ p. 721), with conspicuous bract 

 and ovuliferous scales; on ripening, the scales disarticulate from the axis of the cone. 

 Picea, typified by the Spruce Fir {Abies excelsa, cf. fig. 105, vol. i. p. 415), has 

 pendulous cones, with persistent scales, and, as a rule, the bract scale remains 

 relatively short. Tsuga Douglasii, the Douglas Fir, and the Hemlock Firs are in 

 certain respects intermediate between the Silver and Spruce Firs. 



In all there are 120 species of Abietinese distributed over the cooler parts of 

 the Northern Hemisphere. 



TaxodiecB. — Are characterized by bearing more than two ovules on the scales of 

 their cones. They include the two big Sequoia-s]iecies of North America, S. 

 gigantea, the Wellingtonia or Californian Mammoth Tree, and S. sempervirens, the 

 Red-wood, both of which attain to huge dimensions. Taxodium distichum, the 

 so-called Deciduous Cypress, interesting on account of the curious knee-like roots 

 which it produces above ground, Cryptomeria japonica, and Sciadopithys verti- 

 cillata, the Umbrella Pine of Japan, all cultivated in this country as ornamental 

 trees, are members of this group, which comprehends some 12 species in all. 



CtLpressinece. — Are characterized by the fact that their cones have their scales 

 in whorls, not spirals {cf figs. 336 " and 336 ^ on p. 442, and figs. 337 ^- *■ ^- p. 443). 

 They include about 80 species, amongst them the Cypress {Cupressus), Arbor Vitae 

 {Thuja), JvMiperus, and other ornamental genera. 



TaxacecB. — Have generally few scales in their female cones, and sometimes, as in 

 Taxus, the Yew {cf fig. 234, p. 145, and figs. 336 ^' 2. s. «• s. p. 442), the ovule is 



