1Adult leaves in the form of imbricate scales [microsporophylls triangular].
1'Adult leaves spreading linear or lanceolate needles or leaves.
2Mature seed completely exposed above short (to 2 mm) cone bracts; juvenile leaves nearly straight, up to twice as wide as thick; adult scales appearing gradually on trees several meters high.
2'Mature seed base overlapped by elongated (3 mm) cone bracts; juvenile leaves strongly bent forward and slightly inward, about three times as wide as thick, adult scales appearing almost abruptly on small specimens about half a metre high
3Microsporophylls triangular; female terminal (occasionally on short lateral branches); leaves bent forward, up to 5 mm long and length about 5 times width.
3'Microsporophylls sharply narrowed above the pollen sacs and lanceolate; female may be lateral in some species; leaves acute, in many species to more than 5 mm long and length generally at least 8 times width.
4Leaves blunt (may be apiculate), width less than twice thickness.
4'Leaves acute, width more than twice thickness
5Mature seed fully exposed above short cone bracts [leaves robust (0.3-0.4 mm thick)]
5'Mature seed barely overtopping elongated cone bracts.
6Leaves spreading their tips bent parallel to the branch or directed outward, blunt or with a small apiculus, becoming triangular in cross section and about as thick as wide, 0.2-0.3 mm thick
6'Leaves crowded and more or less touching near their tips which on mature plants curve inward towards the branch, distinctly apiculate, nearly twice as wide as thick, 0.3-0.4 mm thick
7Leaves triangular in cross section, width no more than three times thickness.
7'Leaves distinctly concave on the underside or wide and flat, width at least 8 times thickness.
8Leaves spreading (nearly straight), 0.3-0.4 mm wide, less than twice thickness, length about 25 times width
8'Leaves bent forward, 0.4-0.6 mm wide and width 2-3 times thickness, length no more than 12 times width.
9Leaves mostly 0.4 mm wide; male 6-7 mm long; microsporophyll barely 1 mm long; mature seed exposed
9'Leaves up to 0.6 mm wide; male more than 7 mm long; microsporophyll 1.5-2 mm long; mature seed partly covered by elongated cone bracts.
10Leaves slightly bent forward, length up to 10 times width; male 7-9 mm long.
10'Leaves strongly bent forward, length more than 10 times width; male about 12 mm long
11Leaves at least 3 mm long.
11'Leaf about 1 mm long, strongly bent forward
12Female terminal, bracts about as long as leaves, mature seed partly covered; leaves up to 7 mm long, apex abrupt and bent forward.
12'Female mostly lateral, bracts much smaller than leaves, mature seed exposed; leaves at least 6 mm long.
13Leaves 3-5 mm long, only slightly bent (male unknown)
13'Leaves 5-7 mm long, strongly bent; microsporophyll very long (5-6 mm)
14Leaves slightly bent forward and concave, lanceolate, narrowly acute.
14'Leaves straight and flat, linear, more or less abrupt at the apex, up to 10 mm long
15Leaves 6-10 mm long, 0.5-0.8 mm wide
15'Leaves at least 10 mm long, 0.7-1.3 mm wide