


154 
maintained ; and it is with this object in view that the selection of the 
first name given has been made. 
Information has been derived from an examination of herbarium and 
other specimens, as well as from a free use of a large number of forestal 
and botanical publications; among them Gray’s Manual, Watson’s 
Botany of California, Prof. ©. 8S. Sargent’s Forests of North America, 
Coulter’s Manual of Rocky Mountain Botany, together with various 
Government reports and current botanical and forest literature. In- 
formation has also been derived from the personal observations and 
correspondence of Col. EH. T. Ensign. 
ARTIFICIAL KEY TO GENERA AND SPECIES. 
I, Leaves without a true stem: 
INeedile-shapedior: seal en lille yas ar ares nee ate ate tenet eee CONIFERS. 
Sword-shaped, very long, thick, attached to an unbranched trunk.. | YuCCAs. 
IJ. Leaves with a true stem onl amore or less broad blade.. BROAD-LEAVED TREES. 
iiieteaves none (anomalous) ia.) 2a... ccs-cesce eee eee eater aie eee 49 
CONIFERS. 
Leaves in clusters: 
2,3 (not regularly 4), or 5, with a delicate scaly sheath at the base: PINES: 
Leaves 2in a sheath: 
ito: 2 inehes longs cones wath blumtis¢alese casa ee comets ee eee 5 
1 to 3 (mostly 2) inches long; cones with prickle-pointed scales ......-- 9 
Leaves 3 (sometimes 2) in a sheath: 
24 to 3h inches long; cones with delicate prickles ........--- NG Re ape 8 
> to 6 inches long > cones with strong prickles. 225... 2ncsoose vases ees 7 
Leaves 5 in a sheath: 
1 to 14 inches long; cones with delicate prickles ..........-... evclainiees 6 
1+to 24inches lone scones with-blunt scales -----.22- 22-2... sane aoe 3 
itstor (excephionally.2+ toi) amehes lon@e2 2205 io ten eta tiese ei oer 2 
22 to 4 inches long (often’4 in a sheath) ; seeds large, wingless........-- 4 
anto.4 inches:lones seeds small) winged 2.222 - nse taco eoec see ee ee 1 
More than 5, proceeding from abud: LARCHES: 
14¥ 0720 leavestima clusterseee 5-6 ee ee eee eee eee etree 20 
NO ro aU) eE es Thabo LITE) bara Se Se aoas etsonn Jodsoco qodo SoaaEcen cana Ados 21 
Leaves single: 
Bristling all around the branches; more or less 4-sided and pointed: SPRUCES : 
Leaves very stiff, stout, and Feueiy poner SEH E Se SOObDE 6 Coe ooo eee sao 26655 12 
Leaves moderately stiff, rather slender, awl-pointed : 
Cones with margin of scales entire.....-.-.---------------2 ee eee eee 10 
Cones with margin of scales indented .... .----. ---------- -------+++--+ 11 
Comb-like, or 2-ranked in arrangement on the branches, flat, blunt, notched, 
or pointed: 
Leaves rather thin, onslender branches ; cones hanging, scales persistent: 
HEMLOCKS, etc. : 
With 3-pointed bracts protruding from under the scales....---.-.------ 19 
With no bracts protruding from under the scales: 
Cones 4 to 4 of an inch long, downy - ..---------+ ---2- sete ee er etree 17 
Cones 2 to 3 inches long, not downy ....---------6 se-2 ere cee te tees 18 : 



