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Leaves pinnately compound, leaflets linear; dioecious; stem below ground, or its leaf-bearing apex exposed; Florida and Georgia. |
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1 Zamiaceae |
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Leaves simple, fan-shaped, needlelike, or scalelike; dioecious or monoecious; stem aboveground; widespread. |
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(2) |
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2 (1) |
Leaves deciduous, fan-shaped, dichotomously veined; ovules 2 at ends of long stalks, often only 1 maturing. |
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2 Ginkgoaceae |
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Leaves mostly evergreen (deciduous in Larix and usually in Taxodium, often ephemeral and not photosynthetic in Ephedra), needlelike or scalelike, not dichotomously veined; ovules (and seeds) 1--20 on cone scales or 1 on short stalks. |
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(3) |
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3 (2) |
Longest internodes 2--10 cm (shorter at bases of branches); pollen cones compound, each sporangiophore subtended by a pair of bracteoles; seeds inserted on axis of seed cone, subtended by several pairs or whorls of papery, herbaceous, or fleshy bracts; shrubs (sometimes clambering), neither resinous nor fragrant; dry areas in w United States (se Texas to Oregon and California). |
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6 Ephedraceae |
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Longest internodes 0--1 cm; pollen cones simple, the individual sporophylls not bracteate (usually few sterile bracts at base of cone); seeds inserted on scales of seed cone, scales woody (fleshy and coalescent in Juniperus), or the seeds solitary and not enclosed by bracts or scales in Taxaceae; shrubs or trees, usually resinous and fragrant; widespread. |
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(4) |
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4 (3) |
Seed 1, subtended by but not concealed by inconspicuous sterile bracts, with fleshy or juicy arils; leaves needlelike, spreading in 1 plane ("2-ranked") (except on erect shoots), without resin canals. |
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5 Taxaceae |
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Seeds 1--400 in woody or fleshy cones, enclosed by conspicuous cone-scales, without arils (if cones fleshy then leaves not spreading in 1 plane); leaves needlelike or scalelike, spreading in 1 plane or not, with or without resin canals. |
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(5) |
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5 (4) |
Foliage leaves needlelike, alternate or fascicled, individually abcising from branchlets when shed (except that fascicles in Pinus are shed as units); cone scales imbricate, seeds 2 per scale. |
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3 Pinaceae |
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Foliage leaves needlelike or scalelike, alternate, opposite, or whorled, persistent on branchlets (but most branchlets shed with age); cone scales valvate or imbricate (if imbricate then leaves opposite and scalelike), seeds 1--20 per scale. |
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4 Cupressaceae |
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