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1 Leaves either borne in fascicles of 2-5 (basally bound by a scarious sheath) or on short shoots in clusters of many leaves in apparent whorls. |
..2 Leaves borne in fascicles of 2-5 (basally bound by a scarious sheath); [subfamily Pinoideae] |
..2 Leaves borne on short shoots in clusters of many (>10) leaves in apparent whorls. |
....3 Leaves evergreen; cones 6-12 cm long; [subfamily Abietoideae] |
....3 Leaves deciduous; cones 1-2 cm long; [subfamily Pinoideae] |
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......4 Leaves 4-angled in cross-section; [subfamily Pinoideae] |
......4 Leaves distinctly flattened (2-sided) in cross-section. |
........5 Leaves jointed, on short, persistent base; cones 1-3.8 cm long, pendent; [subfamily Abietoideae] |
........5 Leaves attached directly to twig; cones 4-15 cm long, erect ( Abies) or pendent ( Pseudotsuga) |
..........6 Seed cones erect, disintegrating scale by scale and leaving the cone axis as a persistent spike on the tree; [subfamily Abietoideae] |
..........6 Seed cones pendent, falling whole from the tree; [subfamily Pinoideae] |
1 Leaves opposite or in whorls of 3. |
..2 Longest internodes 2-10 cm long; stems green, Equisetum-like |
..2 Longest internodes < 1 cm long; stems green, brown, or tan, not resembling Equisetum. |
....3 Leaves scale-like or acicular and <16 mm long; mature cones either dry and cone-like, or fleshy and < 12 mm in diameter |
....3 Leaves linear, 15-45 mm long; mature female “cones” fleshy and drupe-like, > 15 mm in diameter |
......4 Leaf apex acute, but not stiff, pungent, or spinose; midvein obviously raised (use 10× magnification) on the upper surface, that surface flat or nearly so, except for the revolute margins; stomatal bands on the leaf undersurface broad, white, together making up about 3/4 of the width of the leaf; drupe-like 'fruit' 18-25 mm long, brown, brown or brownish-orange and not striped |
......4 Leaf apex acuminate, extended into a stiff, pungent spine; midvein not obviously raised on the upper leaf surface, that surface convex-curved; stomatal bands on the leaf undersurface narrow, greenish gray, together making up about 1/4 of the width of the leaf; drupe-like 'fruit' 25-35 mm long, dark-green and also longitudinally striped with paler green, tan, or purple |
1 Leaves either alternate, or in fascicles of 2-5 (basally bound by a scarious sheath), or on short shoots in clusters of many 10-60 leaves in apparent whorls. |
........5 Leaves either borne in fascicles of 2-5 (basally bound by a scarious sheath) ( Pinus) or on short shoots in clusters of many leaves in apparent whorls ( Cedrus, Larix) |
........5 Leaves alternate. |
..........6 Leaves 4-angled in cross-section. |
............ 7 Twigs green |
............ 7 Twigs brown or tan |
..........6 Leaves distinctly flattened (2-sided) in cross-section. |
............ ..8 Leaves (fresh) very soft in texture, seasonally deciduous as twiglets; [primarily Coastal Plain] |
............ ..8 Leaves (fresh) stiffer in texture, evergreen; [collectively more widespread]. |
............ ....9 Leaves tapering from base to a long-acuminate tip |
............ ....9 Leaves with parallel margins for most of their length, or widest near middle and gradually tapering to base and apex, the apex acute, obtuse, or retuse. |
............ ......10 Cone dry, brown, and woody at maturity |
............ ......10 ”Cone” fleshy, red or purplish at maturity |
............ ........11 Seed surrounded by a fleshy scale, appearing drupe-like, this also subtended by a swollen and fleshy receptacle |
............ ........11 Seed partially or fully enclosed in a fleshy aril, the subtending receptacle neither swollen nor fleshy |
............ ..........12 Leaf apex acuminate, extended into a stiff, pungent spine; midvein not obviously raised on the upper leaf surface, that surface convex-curved; stomatal bands on the leaf undersurface narrow, greenish gray, together making up about 1/4 of the width of the leaf; drupe-like 'fruit' 25-35 mm long, dark-green and also longitudinally striped with paler green, tan, or purple, the leathery exterior fully enclosing the seed |
............ ..........12 Leaf apex acute, but not stiff, pungent, or spinose; midvein obviously raised (use 10× magnification) on the upper surface, that surface flat or nearly so, except for the revolute margins; stomatal bands on the leaf undersurface medium to broad, white or whitish-green, together making up about 1/2 or 3/4 of the width of the leaf; drupe-like 'fruit' either 4-7 mm long, red or orange when ripe, with a softly fleshy exterior open at the top (the seed) visible, or 18-25 mm long, brown, brown or brownish-orange and not striped, the fleshy exterior fully enclosing the seed. |
............ ............ 13 Stomatal bands on the leaf undersurface broad, white, together making up about 3/4 of the width of the leaf; drupe-like 'fruit' 18-25 mm long, brown, brown or brownish-orange and not striped, the fleshy exterior fully enclosing the seed; leaf resin canal present, below the vascular tissue (break leaf and use 10× magnification); drupe-like 'fruits' clustered on peduncles |
............ ............ 13 Stomatal bands on the leaf undersurface medium, whitish-green, together making up about 1/2 of the width of the leaf; drupe-like 'fruit' 4-7 mm long, red or orange when ripe, with a softly fleshy exterior open at the top (the seed) visible; leaf resin canal absent; drupe-like 'fruits' solitary, sessile or nearly so |