Lead edit
It is a seedless, vascular plant (with xylem and phloem) that reproduces via spores (not seeds or flowers) and have a life cycle with alternating, free-living sporophyte and gametophyte phases.[1]
Lifecycle edit
Like most plant species, oak fern alternates generations, where there is a diploid generation in the form of a sporophyte (which produces spores), and is followed by a haploid generation in the form of a gametophyte (which produces gametes).[2] The sporangia are found in clusters on the underside of the leaf, called sori.[3] Each sporangium produces multiple sporocytes, with each sporocyte dividing twice, giving rise to four non-sexual spores.[3] Once the spores germinate, they form a prothallus, which develops a number of archegonia (ovaries), and antheridia (spermaries).[3] If water is present, the spermatazoids travel from the antheridia to the archegonia and the egg is fertilized when the two come into contact.[3] An embryo then grows out of the gametophyte, producing a sporophyte.[3]
Description[edit] edit
Gymnocarpium dryopteris has small, delicate fronds up to 40 cm (16 inches) long, with ternately-compound pinnae (leaves). Fronds occur singly. Each petiole grows from one node on a creeping rhizome.[4] On the underside of matured pinnae the naked sori can be found (the Latin generic name gymnocarpium means "with naked fruit"). The species grows in coniferous woodlands and on shale talus slopes.
Gymnocarpium dryopteris, a forest understory plant, is not found in association with Quercus (oak).
In cultivation in the UK this plant and the cultivar "Plumosum" have gained the Royal Horticultural Society’s Award of Garden Merit.
Habitat edit
Oak ferns commonly occur in moist, shady forests, where with wet soil and humid conditions.[5] Often found in drainage areas, ditches and North-facing slopes.[6] Oak fern thrive in soils that are well-drained and have a ph of 4.5-6.4.[6][5] Soil texture varies from silty, clay loams, to sandy gravel.[7] Oak fern occurs at elevations of 1,700-4500 feet along moderately steep slopes with north, east and west aspects.[7]
References edit
- ^ Doust, Jon (1988). Plant Reproductive Ecology: Patterns and Strategies. New York, New York: Oxford University Press. ISBN 0-19-505175-0.
- ^ Windsor, Jon and Lesley Lovett-Doust Professor of Biology the University of (1988-07-07). Plant Reproductive Ecology : Patterns and Strategies: Patterns and Strategies. Oxford University Press, USA. ISBN 978-0-19-802192-6.
- ^ a b c d e Bell, P. R. (1959-12). "The experimental investigation of the Pteridophyte life cycle". Journal of the Linnean Society of London, Botany. 56 (366): 188–203. doi:10.1111/j.1095-8339.1959.tb02492.x. ISSN 0368-2927.
{{cite journal}}: Check date values in:|date=(help) - ^ Lackschewitz, Klaus. (1991). Vascular plants of west-central Montana : identification guide book /. Ogden, UT :: U.S. Dept. of Agriculture, Forest Service, Intermountain Research Station,.
{{cite book}}: CS1 maint: extra punctuation (link) - ^ a b Cooper, Stephen V.; Neiman, Kenneth E.; Roberts, David W. (1991). Forest habitat types of northern Idaho: A second approximation (Report). Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station.
- ^ a b "Adirondack upland flora: an ecological perspective". Choice Reviews Online. 30 (05): 30–2431-30-2431. 1993-01-01. doi:10.5860/choice.30-2431. ISSN 0009-4978.
- ^ a b Corns, I.G.W.; Pluth, D.J. (1984-07). "Vegetational indicators as independent variables in forest growth prediction in West-Central Alberta, Canada". Forest Ecology and Management. 9 (1): 13–25. doi:10.1016/0378-1127(84)90035-5. ISSN 0378-1127.
{{cite journal}}: Check date values in:|date=(help)