CONIFERS OF THE EOCKY MOUNTAIN REGION. 39 



he ripe open cones quickly and is easily disseminated by wind, 

 isually germinating the autumn it is shed, and the seedlings estab- 

 ishing themselves before winter. Germination is abundant and best 

 >n moist duff, litter, moss, decayed logs, stumps, etc., both in the 

 »pen and in the densest shade, where seedlings hold their ground with 

 emarkable power. The tree does not reproduce itself readily 

 p'here frequent fires have destroyed the ground cover or forest 

 over to such an extent that soil moisture is materially reduced. 

 )onsiderable quantities of the seed are eaten by squirrels. 



LONGEVITY. 



Western red cedar is a slow-growing tree and the extreme age 

 attained is at present imperfectly known, chiefly because the centers 

 •f the largest trees cut are usually decayed, thus preventing an 

 iCCurate count of the annual rings of growth. It may, however, 

 »e regarded as very long-lived. Trees 24 to 40 inches in diameter 

 ,re from 200 to 510 years old. Some of the largest trees are un- 

 [uestionably from 800 to 1,000 years old.^^ 



FAMILY RELATIONSfflPS OF YEW TREES-^^ 



The trees and shrubs which belong to the family Taxacese (yews 

 r yewhke trees) differ fundamentally from the true cone bearers, 

 ;onifer£e, in producing male flowers on one tree and female flowers 

 n another, flowers of both kinds very rarely occurring on different 

 larts of the same tree. The conifers usually bear male and female 

 owers on the same tree, each sort being on different branches or 

 arts of them.^* 



The leaves of Taxaceous plants are evergreen, flat, narrowly 

 mce-shaped, and appear to grow (in our native species) in spreading 

 nes on two opposite sides of the branches (PI. XIII). The fruits 

 iffer from those of conifers in being almost or entirely enveloped 

 1 a pulpy covering. In the case of the yews of this group it is a 

 mall, berryhke, bright-colored cup (PI. XIII, a), the hard seed 

 eing embedded in a juicy, sticky outer pulp. 



In the case of other members of the family the covering of the fruit 

 ; firm, practicaUy complete, and similar in appearance to an olive.^^ 



62 See footnote No. 51, p. 36. 



S3 The class relationship of the yew trees is briefly discussed in Forest Service Bulletin No. 207, The 

 yrpress and Juniper Trees of the Rocky Mountain Region, p. 3, 1915. 



M There are, therefore, fewer seed-bearing individuals among the yews and their allies than among 

 me-bearers, since only trees bearing female flowers produce seed. Hence, in thinning a stand of Taxa- 

 ous timber both male and female trees should be preserved as near to each other as possible if reseeding 

 expected to take place, for pollen of the male flowers is carried to the female flowers only by the wind, 

 male trees are distant more than 25 or 30 yards from the female tree, only the strongest wind, blowing 

 ; the right time, will effect fertilization. 

 66 See fig. 75, Forest Trees of the Pacific Slope, p. 192, 1908. 



