16 HOUGH'S AMERICAN WOODS. 



k. 2-5 in. long; leaves 



Dark-green above, flat, flexible and conspicuously emarginate. 



224. A. GRANDIS. 

 Blue-green above, flat, rounded or acuminate at apex. 



173. A. CONCOLOR. 



k*. 3^-6 in. long 249. ABIES AMABILIS. 



k 3 . 6-9 in. long; leaves blue-green, 4-sided 174. ABIES MAGNIFICA. 



i 2 . Longer than the cone scales. 



Spatulate, refiexed and nearly covering the scales; cones 6-8 in. 



long 225. ABIES NOBII is. 



Obcordate with long exserted awl-shaped central lobe; cones 3-4 



in. long 248. ABIES VENUSTA. 



7i-. Nodding, small (about 2 in. long), scales persisting on the axis and 



entire at tip 100. PICEA ALBA. 



h z . Pendent; scales incisely denticulate. 



2^-4 in. long; leaves flattened . . . 149. PICEA SITCHENSIS. 



1-3 in. long: leaves tetragonal 247. PICEA ENGELMANNI. 



gr 4 . Cylindrical oblong ; bracts much exserted (Pseudotsuga) ; cones 



2-3 in. long 150. P. TAXIFOLIA. 



5-8 in. long 172. P. MACROCARPA. 



g*. Ovoid or roundish, small, 9 lines or less in length, scales persistent on 



the axis at maturity 23. LARIX AMERICANA. 



gr 6 . Oblong, 1-1| in. long; scales numerous and shorter than bracts. 



250. LARIX OCCIDENTALIS. 



e 2 . Valvate, bractless, wedge-shaped, spreading, each with 3-7 inverted 

 ovules ; cone woody, oval and 



2-3 in. long, scales usually 25-30 142. SEQUOIA GIGANTEA. 



1 in. or less, scales short, 20 143. SEQUOIA SEMPERVIRENS. 



cf j . Scales few, persistent, bractless ; cone 

 e. Oblong and erect, with scales more or less thickened at tip, 

 /. Loosely imbricated, 8-12, thinnish. 



Four scales only fertile 24. THUJA OCCIDENTALIS. 



Six fertile 220. THUJA GIGANTEA. 



/. Valvate, 4-6, thick, only two scales fertile. 



141. LlBOCEDRUS DECURRENS. 



e 3 . Globose or subglobose, maturing the 

 /. First season, and in diameter about 



i in 74. CHAMJECYPARIS THYOIDES. 



in 241. CHAM^CYPARIS LAMSONIANA. 



in 240. CHAM^ECYPARIS NOOTKATENSIS. 



Second season and 

 g. -f in. in length; leaves conspicuously glandular; branchlets 



Stout 239. CUPRESSUS ARIZONICA. 



Slender 219. CUPRESSUS MACNABIANA. 



f/ 9 . f-1 in.; leaves obscurely glandular 166. CUPRESSUS GOVENIANA. 



f/ 3 . 1-1| in. leaves obscurely glandular 195. CUPRESSUS MACROCAK PA. 



d 3 .' Scales several, breaking apart at maturity; cones subglobose. 



119. TAXODIUM DISTICHUM. 

 e 2 . Scales. 



d. Thin, 3-lobed and deciduous, subtending very small samarse (Betuld). 

 e. Cones erect, 



Sessile, ovoid-oblong, 1 in. in length 17. B. LUTEA. 



With downy peduncle, ovoid, smaller 95. B. NIGRA. 



e 2 . Cones suberect, ovoid-oblong ; scales thicker and with short divergent 



lobes ; wing of nutlet not broader than the body 44. B. LENTA. 



e z . Cones pendent, cylindrical and about 



1 in. in length 70. B. POPULIFOLIA. 



If in. in length; scales 



Glabrous 43. BETULA PAPYRACEA. 



Puberulous, with ciliate margin 236. BETULA OCCIDENTALIS. 



cZ 8 . Thick, woody and persistent, ovoid-oblong 



J-J- in. long; leaves pale-puberulous beneath.. 163. ALNUS RHOMBIFOLIA. 

 i| 1 in. long; leaves rusty pubescent beneath. . . . 217. ALNUS OREGONA. 

 c 3 . Scales closed carpels, growing from an elongated receptacle and consoli- 

 dated. 



