Search results
Results from the WOW.Com Content Network
In botany, a sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls (whether they are microphylls or megaphylls) bear either megasporangia and thus are called megasporophylls , or microsporangia and are called microsporophylls .
Flowering plants contain microsporangia in the anthers of stamens (typically four microsporangia per anther) and megasporangia inside ovules inside ovaries. In all seed plants, spores are produced by meiosis and develop into gametophytes while still inside the sporangium. The microspores become microgametophytes (pollen).
In flowering plants, the gametophytes are very reduced in size, and are represented by the germinated pollen and the embryo sac The sporophyte produces spores (hence the name) by meiosis , a process also known as "reduction division" that reduces the number of chromosomes in each spore mother cell by half.
A strobilus (pl.: strobili) is a structure present on many land plant species consisting of sporangia-bearing structures densely aggregated along a stem.Strobili are often called cones, but some botanists restrict the use of the term cone to the woody seed strobili of conifers.
The male cones are solitary, ovoid, 30 cm long and 7.5 cm broad, with an apical spine and rhomboid sporophyll face. The species is unusual in that it contains a layer of fleshy material between the sarcotesta and the sclerotesta that is thought to aid the seed by providing it with a source of water. As cycad seeds have no dormancy, this would ...
A plant which completes its life cycle (i.e. germinates, reproduces, and dies) within two years or growing seasons. Biennial plants usually form a basal rosette of leaves in the first year and then flower and fruit in the second year. bifid Forked; cut in two for about half its length. Compare trifid. bifoliate
The term spore derives from the ancient Greek word σπορά spora, meaning "seed, sowing", related to σπόρος sporos, "sowing", and σπείρειν speirein, "to sow". In common parlance, the difference between a "spore" and a " gamete " is that a spore will germinate and develop into a sporeling , while a gamete needs to combine with ...
Right: the dry brown stalk, yellow: two seeds, left: the strongly hairy, flat part of the sporophyll. The method of pollination for Dioon plants, whether by wind or animals, has not yet been conclusively determined. The characteristics of the pollen, such as being light, dry, and present in large quantities, suggest wind pollination, which ...