タイトルまたは説明

Sequoia is a genus in the cypress family Cupressaceae, containing the single living species Sequoia sempervirens. Common names include Coast Redwood and California Redwood. California native. It is one of the largest trees of the world. Fast growth when it is young. It can reach height of *0 m. to *0 m. This tree stands straight up, hurled, pyramidal with horizontal to slightly drooping branches. The summit is narrow and round. The tree is deprived of branches on a third or half its height. The sequoia has a very broad trunk (9 m diameter). It has thick bark (*5 - *0 cm), fibrous and crevassed, of a red-orange color, and a flexible, spongy texture. The wood, of excellent qualities, deprived of resinous channels, is imperishable. It resists well to insects and fires. It is used in joinery. An adult tree produces more than 1.**0 m ³ of wood. The leaves are laid out on the secondary branches in two rows of long flattened needles. They are green on top and blue-white bands below. The leaves of the principal branches are scale-like. The foliage is persistent and aromatic. The tree is monoic. The male flowers ( 2 mm), are in the shape of yellowish droplets and the female flowers are in a narrow and greenish cones ( 4 mm). Flowering takes place in winter (February but they where on the tree since last autumn). It has tiny inflorescences at the end of the short branches. The seed cones are ovoid, ****2 mm long, with ****5 spirally arranged scales; pollination is in late winter with maturation about **9 months after. Each cone scale bears **7 seeds, each seed **4 mm long and 0.5 mm broad, with two wings 1 mm wide. The seeds are released when the cone scales dry out and open at maturity. The pollen cones are oval, **6 mm long. Hardiness zones: ***0 (**0°C/ *5°F, 1°C/ *5°F) in winter. The Sequoia needs a deep, fresh, not very calcareous ground and well-drained well (acid or neutral, fertile). It adores the sun and a sheltered place. This tree requires much water. It also needs a certain atmospheric humidity. Be careful, the growth and young plants are frost-susceptible spring.