PIN us. 309 



thickened with apophysis unarmed or with deciduous prickles. Seeds 

 Kinall with elongated wings : 



Banksiana, densiflora, Jialepensis, mops, Laricio, montana, resinosa, 

 sylvestris, Thunbergii. 



Upwards of seventy species of Phms are distinguished by botanists; 

 they are spread over the northern hemisphere from the limits of 

 arborescent vegetation in the arctic and sub-arctic regions to beyond 

 the northern Tropic. Of these seventy species, twenty-four are endemic 

 in the eastern, and the remainder in the western continent. On 

 the eastern continent, with the exception of Pinus sylvestris which 

 is spread over the great plains of Europe and northern Asia, the 

 Pines mostly follow the great mountain ranges, in places forming 

 forests of considerable extent, covering rocky slopes unsuitable for 

 tillage and occasionally ascending to the timber line. Two outlying 

 species occur within the eastern tropics : P. Merkimi in Sumatra 

 and the Malay peninsula, and P. insidaris in the Philippine Islands ; 

 and a third (P. canaricnsis) is confined to the Canary Islands. In 

 North America the Pines also follow the great mountain chains, in 

 places forming forests of immense extent ; but they likewise spread into 

 the plains except in the prairie region of the central Mississippi 

 and the elevated plains east of the Eocky Mountains. The high 

 plateau and mountains of central Mexico are covered with Pine 

 forests where twelve or fourteen species have their home and one 

 more inhabits the West India Islands. 



The existing Pines are the descendants of former races, traces of 

 whose ancestral forms first appear in the Jurassic system ; the oldest 

 discovered Pines belong to the Strobus section in which the scales 

 have no apical thickening. In Tertiary times Pines became very 

 abundant, and in the Miocene Age species with two, three and five 

 leaves in a bundle were common in Europe, including Great Britain.* 

 The economic value of the Pines is very great. Many species, 

 especially Pinus sylvestris, P. Strobus, P. ponderosa, P. monticola, afford 

 timber of the highest importance in constructive work, and Pine timber 

 is the staple article of commerce with many ports of northern Europe 

 and British North America. The resinous secretions of several species, 

 notably P. palustris, P. Pinaster and P. lonyifolia, are very abundant, 

 from which turpentine, resin and tar are obtained in immense quantities. 

 In arboriculture, as landscape planting, some of the most ornamental 

 and picturesque of trees are to be found among the Pines, whilst 

 other species are greatly valued for afforesting waste lands, for forming 

 screens for shelter, etc. 



The name Pinus is adopted from classical authors, by whom it was 

 applied indiscriminately to the species inhabiting the Mediterranean 

 region. In modern times, as shown in our Botanical Retrospect, it 

 has been understood by different authors in widely different senses, 

 before the present very natural circumscription of the genus became 

 generally adopted. 



* Fossil Botany, by Solms-Laubach, Garnsey's Translation, p. 57. 



