HAPLOXYLON 



Bases of the bracts subtending leaf-fascicles not decurrent. Staminate flowers not sufliciently 

 developed in the bud to be apparent. Spring-shoots uninodal. Fibro-vascular bundle of the leaf 

 single. Cone symmetrical, of relatively fewer larger scales, its tissues softer. Bark-formation late, 

 the trunks of young trees smooth. Wood soft and with little resin, of uniform color and with rela- 

 tively obscure definition of the annual rings. Tracheids of the medullary rays with smooth walls. 



All the species of this section, except P. Nelsonii, have deciduous fascicle-sheaths. There are but two 

 species of Diploxylon with deciduous sheaths, P. leiophylla and P. Lumholtzii, both of them easily 

 recognized. The deciduous sheath, therefore, is an obvious and useful means for recognizing the 

 Soft Pines. On the characters of the fruit and the wood Haploxylon can be divided into two sub- 

 sections. 



a. Cembra Umbo of the cone-scale terminal. 



b. Paracembra .... Umbo of the cone-scale dorsal. 



Cembra 



Umbo of the cone-scale terminal. Scales of the conelet unarmed. Leaves in fascicles of 5, the 

 sheath deciduous, the two dermal tissues distinct, the hypoderm-cells uniform. Pits of the cells of 

 the wood-rays large. 



Seeds wingless. 



Cones indehiscent I. . . . Cembrae. 



Cones dehiscent II. . .Flexiles. 



Seeds with an adnate wing III. .Strobi. 



I. CEMBRAE 



Seeds wingless. Cones indehiscent, deciduous at maturity. 



In this group of species there is no segregation of sclerenchyma into an effective tissue. The cones 

 are inert under hygrometric changes and may always be recognized in herbaria by their persistent 

 occlusion and soft tissues. The seeds are released only by the disintegration of the fallen cone. There 

 is, however, a vicarious dissemination by predatory crows (genus Nucifraga) and rodents. 



Leaves serrulate, their stomata ventral only. 



Cones relatively larger, the apophyses protuberant 1. koraiensis. 



Cones relatively smaller, the apophyses appressed 2. cembra. 



Leaves entire, their stomata ventral and dorsal 3. albicaulis. 



1. PINUS KORAIENSIS 



1784 P. STROBTJS Thunberg, Fl. Jap. 275 (not Linnaeus). 



1842 P. KORAIENSIS Siebold & Zuccarini, Fl. Jap. ii. 28. 



1857 P. MANDSCHURiCA Ruprccht in Bull. Acad. Sci. St. Petersb. xv. 382. 



Spring-shoots more or less densely tomentose. Leaves from 8 to 12 cm. long, serrulate, stomata 

 ventral only, resin-ducts medial and confined to the angles. Conelets large, subterminal, or on 

 young trees often pseudolateral. Cones indehiscent, from 9 to 14 cm. long, short-pedunculate, ovoid- 

 conical or subcylindrical ; apophyses dull pale nut-brown, rugose, shrinking much in drying and 



