6. Tsuga Carr. Hemlock. 
frees with needle-like foliage, alternate and spiral, spreading in all 
directions or appearing somewhat 2-ranked, rather soft, blunt, flattened or 
somewhat 5-angled, decurrent and jointed at the base, persistent for sev- 
eral years, leaving a short, appressed, stubby base beneath the joint when ; 
shed. ‘The staminate cones axillary on second year wood, globose, the 2-obshbared:} 
anthers globose; ovulate cones borne on the same plant, "solitary, terminal, =< 
formed of a spiral series of fertile sporophylls (ie. scales) each bearing a 
two ovules on the upper surface, each subtended by an inconspicuous bract; 2 
fruit a more or less woody pendent cone, maturing the first year and 
deciduous or persistent the following year, the scales thin; seeds winged. 
Cotyledons 3-6, flat. 
Leguctentinentinees 
7, 
ONeedles flattened; triangular in cross-section, plump, 
Cc. stomata prominent on both surfaces, cones 5-6 cm. 
longQo__>- > m. Mertensiana 
_ 
ONeedles flat, the upper surface green, the stomata : 
4 Eeanen? only beneath; cones £ed-5 cme longe ). 2B. heterophylla + 
a4 
i 
1. T. heterophylla (Raf.) Sargt. Coast Hemlock. ———>A massive forest 
(ij) tree commonly 50 m. tall, charac teryzed by the feathery foliage and drooping 
branchlets. Trunk of mature trees with slight taper, but tapering rapidly in 
the upper parts; D.B.H.e cormonly 1-2 m. or more in old trees. Branchlets 
straw-colored or tan,.woolly, gray the second year, roughened by the persistent 
leaf-bases and rathe scurfy; young bark dark gray with but a slight lustre, 
marked by transverse lenticels, breaking into irregular flakes which on falling a 
away leave a reddish-tinged scar; mature bark gray with a reddish cast, 5-4 Cme ‘s 
thick, cerise when cut, longitudinally furrowed, the ridges flat, forming 
fairly regular plateg, 2-5 cm. x 15-40 cm., the fissures forming "a net work. : 
Crown conical, acute when young, rather obtuse in old trees, the leader droop- : 
, ing. Branches spreading in young trees, drooping perceptibly in older trees, 
pruned to a height of 18-20 m. in the maturing forest. Foliage yellowish 
green en masse, needles deciduous in 3d-5th year, very irregular in length, 
flat and thin, 5-20 mm. lons, averaging about 12-15 mn., dseguemekr in rather a 
flattened sprays, oblon,, blunt, narrowed abruptly at the base to a petiole 3 
1 mm. long or less, with a pronounced twist, margin sparingly and minutely 
toothed, the midvein impressed above, prominent beneath, with 5-6 rows of 
white stomata on either side, the lower surface hence glaucous, the leaf-base 
C@ deourrent about fans, the apex scarcely free, however. sStaminate cones 3-4 m. 
in di 2 globose, vaired, dehiscent by a valve from the base, tne stalk 
long; ovulate cones borne mostly in the upper half of the crown, 
terminal, 25-30 mm. lon:;, narrowly elliptical before opening, green, the 
? 
scale margins often reddish, becomin; ovate to subglobose after osening, tan 
en ee ee 
or Clay-colored, openings in carter ver, deciduous the same year or sometines 
persisting; scales obovate, lo-lt ma. lonz, rube-ulent; seeds S mae longs, 
(i Wing 5-65 mm. x 9-10 mm. Seedlins 1-2 cm. tall, davk green, cotyledons 3-4, 
6-7 mae long, 1 mn. wide, narrowed at the a-ex wat rather olunt, first leaves j 
ne dm , ee ae = wp octet Plat _ 7 > 
alternate, but apparently ‘horlecd, apex blunt, mrgins minutely serrulate, the 
