248 THE CULTIVATED EVERGREENS 



dier than the preceding one, but has not yet been sufficiently tested. 

 Keteleeria sacra, Beiss., K. Evelyniana, Mast., and K. formosana, Hayata, 

 are probably synonyms or only varieties of K. Davidiana. 



21. ABIES, Mill. FIR 



Evergreen trees of pyramidal habit, with whorled spreading branches; 

 bark usually smooth, thin on young trees, thick and furrowed at base of old 

 trees; winter-buds with or without resin: leaves persistent for many years, 

 linear to linear-lanceolate, entire, sessile, contracted above the circular base 

 and leaving a circular scar as they fall, flattened, usually grooved and deep 

 green and lustrous above, with 2 white or pale stomatic bands and keeled 

 beneath, rarely 4-sided with stomata on all 4 sides, rounded and variously 

 notched or pointed at the apex, usually appearing 2-ranked by a twist at 

 their base, with 2 resin-canals which are either marginal (lying close to the 

 epidermis of the under side) or internal (surrounded by the tissue of the leaf), 

 and with 2, rarely 1, vascular bundles; on upper fertile branches crowded, 

 more or less erect, often incurved or falcate, thickened or quadrangular, 

 obtuse or acute: flowers axillary, appearing in early spring from buds formed 

 the previous summer on branchlets of the year, surrounded by involucres of 

 the enlarged scales of the flower-buds; stamina te flowers pendent on branches 

 above the middle of the tree; fertile flowers globular, ovoid or oblong, with 

 numerous 2-ovuled imbricate scales, erect on the topmost branches : fruit an 

 erect ovoid or oblong-cylindrical cone, its scales longer or shorter than their 

 bracts, broad and rounded or truncate at the incurved apex, narrowed at 

 base into a long stipe; seeds with large thin wing; cotyledons 4-10. (Abies 

 is the ancient Latin name of the silver-fir.) — About 35 species in northern 

 and mountainous regions of the northern hemisphere, often gregarious, 

 extending south in America to Guatemala, in the Old World to northern 

 Africa and the Himalayas. 



The species of this genus are among the handsomest and stateliest conifers. 

 They succeed best in a cool and humid climate and are particularly impatient 

 of dust and smoke, therefore not suited for planting in or near cities; only 

 a few, like A. concolor, are more resisting. All the known species have been 

 introduced and are in cultivation except A. maroccajia and A. Kawakamii. 



The following key is artificial and based primarily on vegetative characters; 

 it does not pretend to express the natural affinities of the species and their 

 sequence, therefore differs from that of the enumeration where the species 

 are grouped as much as possible according to their relationship. The de- 

 scriptions of the leaves refer to those of sterile branches; the leaves of fertile 

 branches are as a rule shorter and thicker, usually more or less upturned and 

 ascending, acute and often spiny-pointed and have in some cases internal 



