54 The Spruces 



III. THE SPRUCES 



GENUS PICEA LINK 



OXTAINING about i8 or 20 species of tall conic trees, the genus 

 Picea is confined to the cooler regions of the northern hemisphere; in 

 America they range northward in the mountains from the CaroHnas 

 and New Mexico to Canada, where they extend across the continent 

 and north to the Arctic Ocean. They are usually trees of considerable stature, 

 except where reduced by altitude or latitude. 



The trunks are straight, gradually tapering to the top, often quite thick and 

 enlarged at the base, and have scaly, seldom deeply channeled bark. The 

 branches are in whorls at regular inters^als, slender, horizontal, or sometimes 

 drooping; the branchlets are pendulous. The winter buds are covered by many 

 scales, the outer ones being the thickest, and persist for a time as a ring around the 

 base of the newly formed twig, leaving, when falling, a ring-hke scar. The leaves 

 are linear, 4- sided, and bear stomata on all sides; or they are sometimes flattish 

 and have stomata on the upper side only ; they are spirally arranged on the branch- 

 lets, pointing in all directions, seldom appearing 2-ranked, sometimes incurved, 

 usually pointed, and contain i or 2 resin-ducts close to the lower epidermis 

 and are jointed to narrow cyhndric persistent woody stalks called sterigmata, 

 from which they fall in the course of seven to ten years or upon drying. The 

 flowers are monoecious, appearing early in the spring from buds of the previous 

 year. The staminate inflorescence is axillary, surrounded by enlarged bud-scales, 

 stout, stalked, and erect, sometimes nodding on long stalks, yellow or scarlet; the 

 numerous spirally disposed anthers open lengthwise. The pistillate inflorescence 

 is terminal, oblong to cylindric, erect on short stalks, and pale yellow to scarlet. 

 The cones are ovoid to oblong, pendulous, stalkless or short-stalked, maturing the 

 first season, falling ofT during the following winter or remaining for many years; 

 their persistent scales are obovate, or rhomboidal, entire or variously toothed, 

 much longer than the bracts, gradually diminishing in size, and sterile toward 

 each end of the cone. The two seeds at the base of eacl^Jertile scale are 

 obliquely ovoid or oblong, usually pointed at the Vjase, crustaceous, and of 

 various shades of brown, the wing large; cotyledons 4 to 15. 



The spruces are among the most valuable timber-producing trees of the northern 

 hemisphere. The resinous exudations of some of the species are used as are the 

 "turpentines" from allied genera. They are abundantly represented by fossil 

 leaves in the Miocene epoch of Europe. Picea is the old classic name of the Spruce, 

 the type species being the Norway spruce, Picea Abies (L.) Karsten, of Europe. 



Leaves 4-sided. 



: Eastern and northern trees; cone-scales ver}' obtuse. 



Twigs and sterigmata smooth, often glaucous; cones oblong-cylindric. i. P. canadensis. 



Twigs hair)'; cones ovoid to oval. 



