Search results
Results from the WOW.Com Content Network
Conifer cone. A mature female big-cone pine (Pinus coulteri) cone, the heaviest pine cone. A young female or seed cone on a Norway spruce (Picea abies) Immature male or pollen 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 ...
Pinophytina. Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (/ pɪˈnɒfɪtə, ˈpaɪnoʊfaɪtə /), also known as Coniferophyta (/ ˌkɒnɪfəˈrɒfɪtə, - oʊfaɪtə /) or Coniferae. The division contains a single extant class, Pinopsida.
Encephalartos sclavoi cone, about 30 cm long. Over 1,000 living species of gymnosperm exist. [2] It was previously widely accepted that the gymnosperms originated in the Late Carboniferous period, replacing the lycopsid rainforests of the tropical region, but more recent phylogenetic evidence indicates that they diverged from the ancestors of angiosperms during the Early Carboniferous.
A pollen tube is a tubular structure produced by the male gametophyte of seed plants when it germinates. Pollen tube elongation is an integral stage in the plant life cycle. The pollen tube acts as a conduit to transport the male gamete cells from the pollen grain —either from the stigma (in flowering plants) to the ovules at the base of the ...
The seed cones are green, 6–12 cm (2.4–4.7 in) long and 5–10 cm (2.0–3.9 in) in diameter, and mature about 18–20 months after wind pollination. They disintegrate at maturity to release the seeds which are small and brown, thin and papery with a wing around the edge to aid wind-dispersal. [ 3 ]
The seed cones are ovoid-cylindric, 2 to 5 cm (3 ⁄ 4 to 2 in) long, with 40 to 80 seed scales; each scale bearing an exserted 4 to 8 mm (3 ⁄ 16 to 5 ⁄ 16 in) bract. The cones are green [ 5 ] to reddish purple when immature, turning brown and the scales opening flat or reflexed to release the seeds when mature, four to six months after ...
The cones are small and inconspicuous at pollination in late winter, the pollen cones in clusters of 10–30 together, the female cones singly or 2–3 together. [ 6 ] The seed cones mature in 7–8 months to 2.5–4.5cm long, ovoid to globose, with spirally arranged scales; each scale bears 3–5 seeds .
Picea breweriana. Brewer spruce, Ridge above Bear Lake, Siskiyou Mountains, Ca. Picea breweriana, known as Brewer spruce, [2][3] Brewer's weeping spruce, or weeping spruce, is a species of spruce native to western North America, where it is one of the rarest on the continent. The specific epithet breweriana is in honor of the American botanist ...