1a. Leaves all scale‑like or awl shaped, less than 12 mm long…………….……….2
1b. Leaves mostly needle‑like or broad, usually more than 12 mm long..…….11
2a. Leaves opposite or whorled………………………………………………………….….. 3
2b. Leaves spiral or alternate……………………………………………………………………9
3a. Plants usually shrubs, cones berrylike, fleshy, scales fused,
branchlets terete, not flattened.……………………………………..Juniperus
3b. Trees, cones woody…………………………………………………………………………. 4
4a. Cones scales peltate, meeting at edges but not overlapping…………………. 5
4b. Cone scales not peltate, flattened, more or less attached at one
end, and usually imbricate (overlapping like shingles); branchlets
forming flat sprays………………………………………………………………………… 6
5a. Cones less than 15 mm in diameter; branchlets forming flat
sprays..…………………………………………………………Chamaecyparis
5b. Cones more than 15 mm in diameter; branchlets terete.………….Cupressus
6a. Leaves apparently in whorls of 4; internodes longer than wide;
cone scales in 3 pairs, basal pair small, middle pair fertile,
upper pair sterile and connate.…………………………..Calocedrus decurrens
6b. Leaves opposite; internodes about as long as both leaves are
wide…………………………………………………………………………………………….. 7
7a. Leaves with large glaucous patch below.…………………..Thujopsis dolobrata
7b. Leaves without large glaucous patch below……………………………………….. 8
8a. Branchlets in horizontal plane, whitish below; cone scales
thin…………………………………………………………………………..Thuja
8b. Branchlets in vertical plane, green on both sides; cone scales
thickened and slightly hooked.…………………………………..Platycladus
9a. Lateral branchlets deciduous, less than 2 mm wide; pollen bearing
cones catkin‑like in drooping panicles; seeds 2 per scale
..…………………………………………………Taxodium distichum var. nutans
9b. Lateral branchlets evergreen, more than 2 mm wide (including
leaves); pollen bearing cones not as above; seeds more than 2 per
scale…………………………………………………………………………………………….10
10a. Apex of cone scale with crest bearing several recurved teeth,
free portion of leaves more than 5 mm long..…………Cryptomeria japonica
10b. Apex of cone scale without crest of teeth, free portion of leaf
usually less than 5 mm long..………………………Sequoiadendron giganteum
11a. Leaves and branchlets opposite, deciduous……Metasequoia glyptostroboides
11b. Leaves and branchlets spiral or alternate or borne in bundles or
clusters………………………………………………………………………………………..12
12a. Leaves needle‑like, less than 4 mm wide…………………………………………..13
12b. leaves ovate, not needle‑like, 8 mm or more wide at widest
point..…………………………………………………………Araucaria araucana
13a. Leaves more than 80 mm long, 3 mm or more wide, borne in
whorls of 15‑25 at ends of shoots………………………Sciadopitys verticillata
13b. Leaves less than 80 mm long, or less than 2 mm wide.……………………….14
14a. Leaves in bundles, or clusters, on short shoots…………….…………………….15
14b. Leaves solitary, alternate or spirally arranged……………………………………17
15a. Leaves in bundles of 2‑5.…………………………………………………..Pinus
15b. Leaves in clusters of 8 or more on short shoots…………..……………………..16
16a. Leaves angled and evergreen; cones large, more than 75 mm
long, erect on branches..…………………………………………………Cedrus
16b. Leaves flat and deciduous, cones less than 75 mm long, variously
oriented..……………………………………………………………………Larix
17a. Leaves lanceolate, 3‑4 mm wide at widest point, stiff and
sharp pointed..………………………………………..Cunninghamia lanceolata
17b. Leaves linear, less than 3 mm wide if stiff and sharp
pointed………………………………………………………………………………………..18
18a. Dead branchlets falling with needles attached, cone scales
peltate, leaves 2 ranked………………………………………………………………….19
18b. Dead needles falling individually; cone scales not peltate
or seed not borne in cones……………………………………………………………..20
19a. Tree deciduous; needles light green, soft; pollen cones in
drooping panicles; seeds 2 per cone scale……………….Taxodium distichum
19b. Tree evergreen; needles dark green, stiff; pollen cones
solitary, seeds about 5 per cone scale..…………………Sequoia sempervirens
20a. Seeds surrounded by fleshy aril, not borne in a cone; leaves
dark green above, light green below, without whitish lines
of stomates; often shrubs.………………………………………………..Taxus
20b. Seeds borne in woody cones, leaves with whitish lines of
stomates below and/or above………………………………………………………..21
21a. Branchlets roughened by projecting, woody persistent leaf
bases (sterigmata)………………………………………………………………………….22
21b. Branchlets smooth, without sterigmata……………………………………………..23
22a. Leaves blunt, with short petioles.…………………………………………Tsuga
22b. Leaves sharp pointed, sessile on sterigmata………………………………Picea
23a. Leaves sessile, leaf scars circular; cones upright,
disintegrating when mature..……………………………………………..Abies
23b. Leaves short petioled, leaf scar oval; cones pendant, each scale
with an exserted 3‑pronged bract, falling whole.……………….Pseudotsuga