Search results
Results from the WOW.Com Content Network
The gymnosperms (/ ˈ dʒ ɪ m n ə ˌ s p ɜːr m z,-n oʊ-/ ⓘ nə-spurmz, -noh-; lit. ' revealed seeds ') are a group of woody, perennial seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include conifers, cycads, Ginkgo, and gnetophytes, forming the clade Gymnospermae [2] The term gymnosperm comes from the ...
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (/ p ɪ ˈ n ɒ f ɪ t ə, ˈ p aɪ n oʊ f aɪ t ə /), also known as Coniferophyta (/ ˌ k ɒ n ɪ f ə ˈ r ɒ f ɪ t ə,-oʊ f aɪ t ə /) or Coniferae. The division contains a single extant class, Pinopsida.
The name comes from the Greek for "naked seed"; the egg cells are not protected by ovaries, as in flowering plants. [4] Gymnosperms are divided into 12 families of trees, shrubs and woody vines. [5] Sequoiadendron giganteum, the giant redwood, is the largest tree in the world, and Sequoia sempervirens, the coastal redwood, is the tallest. [6]
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. They are usually woody and variously conic, cylindrical, ovoid, to globular, and have scales and bracts arranged around a central axis, but can be fleshy and berry -like.
Gnetophyta (/ n ɛ ˈ t ɒ f ɪ t ə, ˈ n ɛ t oʊ f aɪ t ə /) is a division of plants (alternatively considered the subclass Gnetidae or order Gnetales), grouped within the gymnosperms (which also includes conifers, cycads, and ginkgos), that consists of some 70 species across the three relict genera: Gnetum (family Gnetaceae), Welwitschia (family Welwitschiaceae), and Ephedra (family ...
There are 27 families of flowering plants whose earliest ancestors diverged from what became the two most prominent groups of flowering plants, the eudicots and monocots. [1] [a] They are quite diverse, with woody and non-woody plants, evergreen and deciduous shrubs and trees, and plants that grow in soil, in water and on other plants.
Cryptomeria japonica: (left) shoot with mature cones and immature male cones at top; (centre) adult foliage shoot; (right) juvenile foliage shoot Cryptomeria is a very large evergreen tree , reaching up to 70 m (230 ft) tall and 4 m (13 ft) trunk diameter, with red-brown bark which peels in vertical strips.
Among the seed plants, the gymnosperms are a sister group to the subclass Magnoliidae (angiosperms or flowering plants). There are about 1000 extant gymnosperm species, distributed over about 12 families and 83 genera. Many of these genera are monotypic (41%), and another 27% are oligotypic (2–5 species). [27]