G. 103) CLASSIFICATION AND DESCRIPTION 193 
scale-shaped, overlapping, mostly appressed, with generally an acute 
apex, light green in color. Cones oval, 2 to 3 in. long, of about 25 
scales. The largest tree known, 300 ft. high, with a trunk nearly 
30 ft. through, found in California and occasionally planted east, 
though with no great success, as it is 
almost certain to die after a few years. 
2. Sequéia sempérvirens, Endl. 
(Repwoop.) Leaves from 4 to 1 in. 
long, linear, smooth, 2-ranked, flat, 
acute, dark shining green, glaucous be- 
neath; branches numerous, horizontal, 
spreading. Cones 1 in. long, roundish, 
solitary, terminal; scales numerous, 
thick, rough, furnished with an obtuse 
point. A magnificent tree from Cali- 
fornia, where it grows 200 to 300 ft. 
high. In the Kast it can be kept alive 
but a few years even at Washington. 
Genus 108. THUYA. (ARBOR-VIT#.) 
Small, evergreen trees with flat, 2-ranked, fan-like spray 
and closely overlapping, small, appressed leaves of two 
shapes on different branchlets, one awl-shaped and acute, 
the other scale-like, usually blunt and close to the branch. 
Fertile catkins of few, overlapping scales fixed by the 
base; at maturity, dry and spreading. There are scores 
of named varieties of Arbor-vitee sold by the nurserymen 
under 3 different generic names, Thuya, Biota, and Thu- 
yopsis. There are but slight differences in these groups, 
and they will in this work be placed together under 
Thuya. Some that in popular language might well be 
called Arbor-vite (thé Retinosporas) will, because of the 
character of the fruit, be included in the next genus. 
* Seales of the cones pointless, thin, straight. (Thuya)......1, 2. 
* Seales reflexed and wedge-shaped. (Thuyopsis).............. 3. 
* Seales thick, with horn-like tips. (Biota).................... 4, 
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