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Immature male or pollen cones of Rocky Mountain ponderosa pine. (Pinus ponderosa var. scopulorum) A conifer cone or pinecone (strobilus, pl.: strobili in formal botanical usage) is a seed-bearing organ on gymnosperm plants. It is usually woody, ovoid to globular, including scales and bracts arranged around a central axis, especially in conifers ...
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.
The pollen grains mature further inside the ovule and produce sperm cells. Two main modes of fertilization are found in gymnosperms. Cycads and Ginkgo have flagellated motile sperm [31] that swim directly to the egg inside the ovule, whereas conifers and gnetophytes have sperm with no flagella that are moved along a pollen tube to the egg.
Pollen itself is not the male gamete. [4] It is a gametophyte, something that could be considered an entire organism, which then produces the male gamete.Each pollen grain contains vegetative (non-reproductive) cells (only a single cell in most flowering plants but several in other seed plants) and a generative (reproductive) cell.
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds. [ 1 ] Pollinating agents can be animals such as insects, for example beetles or butterflies; birds, and bats; water; wind; and even plants themselves.
Podocarpus spp. are generally dioecious, with the male pollen cones and female seed cones borne on separate individual plants, but some species may be monoecious. The cones develop from axillary buds, and may be solitary or form clusters. [1] The pollen cones are long and catkin-like in shape. They may be sessile or short pedunculate.
Description. Thuja are evergreen trees growing from 10 to 200 feet (3 to 61 metres) tall, with stringy-textured reddish-brown bark. The shoots are flat, with side shoots only in a single plane. The leaves are scale-like and 1 to 10 mm (0.039 to 0.394 in) long, except young seedlings in their first year, which have needle-like leaves.
Cupressaceae is a widely distributed conifer family, with a near-global range in all continents except for Antarctica, stretching from 70°N in arctic Norway (Juniperus communis) [3] to 55°S in southernmost Chile (Pilgerodendron uviferum), further south than any other conifer species. [4] Juniperus indica reaches 4930 m altitude in Tibet. [5]