Gymnosperm
group of plants, at a varying rank From Wikipedia, the free encyclopedia
Remove ads
The gymnosperms are a group of tree plant which includes tales.[1]
They have naked seeds, in contrast to the seeds or ovules of flowering plants (angiosperms). which are enclosed during pollination. Gymnosperm seeds develop either on the surface of scale- or leaf-like appendages of cones or at the end of short stalks (Ginkgo).[2]
Gymnosperms and angiosperms together make up the spermatophytes or seed plants. By far the largest group of living gymnosperms is the conifers (pines, cypresses, and relatives), followed by cycads, Gnetales (Gnetum, Ephedra and Welwitschia), and Ginkgo (a single living species).[3]
Fossil gymnosperms include many that do not belong to the four modern groups, including the so-called "seed ferns" (Pteridosperms) and the "cycadeoids" (Bennettitales). Most of the Gymnosperms became extinct in the Cenozoic era (from 65 million years ago to present day).[4]
Some genera have mycorrhiza, fungal associations with roots (Pinus). In some others (Cycas), small specialised roots have nitrogen-fixing cyanobacteria.
Remove ads
Phylogenetics
| gymnosperms |
| |||||||||||||||||||||
Related pages
References
Other websites
Wikiwand - on
Seamless Wikipedia browsing. On steroids.
Remove ads