IP s t e I s t a 153 



B. Twigs of only one sort, leaves evergreen, not 

 fascicled; cones ripening in one season. 



Abies 

 Piniis Linnaeus, Sp. PI. 1000. 1753. in part. 



Evergreen trees with two kinds of leaves, the 

 primary scale-like, not green, deciduous, scat- 

 tered and spirally arranged upon the long shoots 

 of tlie plant, each having in its axil a dwarf 

 shoot which bears a fascicle of 2-5 (rarely i, 6 

 or 7) acicular foliage leaves surrounded by a 

 sheath of scale-leaves. Flowers monoecious, the 

 staminate with basal involucre-like scales, fas- 

 cicled at the base of the young shoots of the 

 year; stamens numerous, spirally arranged; 

 anther sacs two, parallel, longitudinally dehis- 

 cent, surmounted by a transverse, sub-orbicular 

 crest, or by a knob; pollen grains with two 

 bladder-like appendages. Pistillate flowers sol- 

 itary or clustered, lateral or subterminal; the 

 scales much longer than the bracts; cones ripen- 

 ing at the close of the second season or later, 

 woody, variously shaped, often very large, the 

 scales more or less thickened and callous at the 

 tips. Seeds destitute of resin vesicles, usually 



