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Many Pinus species adapted to this fire-prone environment with serotinous pine cones. A set of conditions must be met in order for long-term seed storage to be evolutionarily viable for a plant: The plant must be phylogenetically able (pre-adapted) to develop the necessary reproductive structures; The seeds must remain viable until cued to release
A mature female big-cone pine (Pinus coulteri) cone, the heaviest pine cone A young female cone on a Norway spruce (Picea abies) Immature male cones of Swiss pine (Pinus cembra) A conifer cone, or in formal botanical usage a strobilus, pl.: strobili, is a seed-bearing organ on gymnosperm plants, especially in conifers and cycads.
The leaves are in fascicles of three, [6] needle-like, yellow-green, twisted, and 9–15 centimeters (3 + 1 ⁄ 2 –6 in) long. The cones are resin-sealed and irregularly shaped, [4] 8–16 cm (3 + 1 ⁄ 4 – 6 + 1 ⁄ 4 in) long and clustered in whorls of three to six on the branches. The scales end in a short stout prickle.
The wood is moderately hard and heavy, weak, light brown colour. The seed cones vary in shape, being rectangular to oval, cone shaped, straight or curved inward. [15] The cones are 3–5 cm (1 + 1 ⁄ 4 –2 in) long, the scales with a small, fragile prickle that usually wears off before maturity, leaving the cones smooth.
Pseudotsuga macrocarpa typically grows from 15–30 m (49–98 ft) in height and 56–155 cm (1 ft 10 in – 5 ft 1 in) in trunk diameter. [6] The growth form is straight, with a conical crown from 12–30 m (39–98 ft) broad, and a strong and spreading root system.
The female cones are large and usually woody, 2–60 centimetres (1–24 inches) long, with numerous spirally arranged scales, and two winged seeds on each scale. The male cones are small, 0.5–6 cm (1 ⁄ 4 – 2 + 1 ⁄ 4 in) long, and fall soon after pollination; pollen dispersal is by wind. Seed dispersal is mostly by wind, but some ...
The pine needles are in fascicles (bundles) of three, distinctively pale gray-green, sparse and drooping, and grow to 20–30 centimetres (8–12 in) in length. The seed cones are large and heavy, 12–35 cm ( 4 + 3 ⁄ 4 – 13 + 3 ⁄ 4 inches) in length and almost as wide as they are long.
The cones thus grow over a two-year (26-month) cycle, so that newer green and older, seed-bearing or open brown cones are on the tree at the same time. Open cone with empty pine nuts. The seed cones open to 6–9 cm (2 + 1 ⁄ 4 – 3 + 1 ⁄ 2 in) broad when mature, holding the seeds on the scales after opening.