sporophylls's Usage Examples:

from sporophylls); that is, they are the result of descending metamorphosis.

The sporophylls may exceptionally undergo further dichotomies and bear more numerous synangia.

The spores, as in the heterosporous Pteridophyta, are of two kindsmicrospores (pollen grains) borne in microsporangia (pollen sacs) on special leaves (sporophylls) known as stamens, and macrospores (embryo-sac) borne in macrosporangia (ovules) on sporophylls known as carpels.

It consists of one or more carpels (megasporophylls), either separate (fig.

These, as in Gymnosperms, are of two kinds, microspores or pollen-grains, borne in the stamens (or microsporophylls) and megaspores, in which the egg-cell is developed, contained in the ovule, which is borne enclosed in the carpel (or megasporophyll).

As with few exceptions the stamen represents a leaf which has been specially developed to bear the pollen or microspores, it is spoken of in comparative morphology as a microsporophyll; similarly the carpels which make up the pistil are the megasporophylls (see Angiosperms).

The male flower of Cycas conforms to the type of structure characteristic of the cycads, and consists of a long cone of numerous sporophylls bearing many oval pollen-sacs on their lower faces.

Moreover there is the fact that the flowers of nearly all the primitive phanerogams, such as the Gymnosperms, consist solely of sporophylls, having no perianth.

Usually, however, other leaves are present which are only indirectly concerned with the reproductive process, acting as protective organs for the sporophylls or forming an attractive envelope.

The male sporophylls are similar in form to the vegetative leaves, but smaller; sunk in their parenchyma are numerous tubular loculi, containing large pollen-grains, which are pluricellular like those of Cordaites; the female fructification had not yet been identified with certainty.

The fertile leaves or sporophylls are generally aggregated on special shoots to form rioweN which may contain one or both kinds The microspores are set free from the sporangiurn and carried generally by wind or insect agency to the vicinity of the macrospore, which never leaves the ovule.