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Pinaceae
See list of 6 genera in this family-
1a. Leaves, at least in part, borne in fascicles or spirally arranged tufts of 2–60 on short shoots
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2a. Leaves annually deciduous, those of the short shoots in spirally arranged tufts of 10–60 [Fig. 44]; each scale of a strobilus without an umbo; bracts exserted in basal portion of strobilus
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2b. Leaves persisting more than 1 year, those of the short shoots in fascicles of 2–5; each scale of a strobilus with an umbo; bracts hidden by scales
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1b. Leaves all borne singly
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3a. Winter buds very resinous, the individual scales concealed by resin; strobili erect, with deciduous scales; leaves attached directly to branchlet and expanded to a circular base
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3b. Winter buds not, or only slightly, resinous, the individual scales visible; strobili pendant at maturity [Figs. 45,47], with persistent scales; leaves either attached to peg-like projections (i.e., sterigmata) from branchlet and narrowed to the attachment or attached directly to the branchlet with an expanded elliptic base
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4a. Bracts of seed cone conspicuously exserted, 3-lobed at apex, the central lobe longer than the lateral lobes; young bark with resin blisters; leaves attached directly to the branchlet and expanded to an elliptic base
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4b. Bracts of seed cone not exserted, not 3-lobed at apex; bark lacking resin blisters; leaves attached to peg-like projections from branchlet and narrowed to the attachment
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5a. Leaf blades flat, petiolate, rounded at apex, dimorphic—longer, spreading ones and shorter, often appressed, ones; terminal shoot nodding
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5b. Leaf blades tetragonous, sessile, pointed at apex, monomorphic; terminal shoot erect
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Each photo represents one genus in this family.