PINACEAE

XXVI. PINACEAE View in CoL 1

Monoecious; resiniferous trees, rarely shrubs, with spirally arranged leaves. Flowers (cones) made up of numerous spirally arranged scales. Scales of male cones (microsporophylls) bearing 2 pollen-sacs on the lower surface. Scales of female cones (megasporophylls) made up of two parts—an upper ovuliferous scale (cone-scale) bearing 2 ovules on the upper surface, and a lower, subtending scale (bract). Fruit a usually woody cone. Seeds winged. 1 Short shoots absent; leaves all solitary 2 Leaves borne on persistent, peg-like projections or cushions 3 Leaves petiolate; resin canal 1, median 4. Picea 3 Leaves sessile; resin canals lateral 3. Tsuga 2 Leavesnotborne onpeg-like projections,but leavingdisc-like scars 4 Leaf-scars circular, not at all projecting; cone erect 1. Abies 4 Leaf-scars elliptical, slightly projecting; cone deflexed or pendent 2. Pseudotsuga 1 Short shoots present, bearing fascicles of two or more leaves 5 Leavesonlongshootsscale-like,not green; shortshootsmuch reduced, bearing 2-5 green leaves 7. Pinus 5 Leaves on long shoots similar to those on short shoots; short shoots prominent, bearing many densely clustered leaves 6 Leaves deciduous; bracts exceeding ovuliferous scales in flower; cones not more than 4 cm 5. Larix 6 Leaves evergreen; bracts minute or absent; cones more than

4 cm 6. Cedrus