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The Life Cycle of Dryopteris

Dryopteris is a genus of ferns commonly called wood ferns. The group includes many species native to the northern hemisphere. The wood ferns, as a group, are adapted to U.S. Department of Agriculture plant hardiness zones 3a through 9b. As with ferns in general, wood ferns reproduce by means of spores rather than seeds.

Mature Fern
- The mature wood fern is the stage in the fern̵7;s life cycle that botanists refer to as the ̶0;sporophyte.̶1; The sporophyte consists of a rhizome, or rootstock, from which roots grow into the soil or substrate, and the frond, or leaf, that grows upward or outward to collect light. The sporophyte is the stage that gives rise to spores that are crucial to the wood fern̵7;s reproductive cycle. Small spore-bearing structures, called sori, develop on the undersides of the mature wood fern̵7;s fronds.
Spores
- Within the sori are even smaller structures termed ̶0;sporangia.̶1; The sporangia are tiny capsules containing the spores that the mature fern has produced. When fully developed and ̶0;ripe,̶1; the spores are ready for release. The sporangia rupture and release the wood fern̵7;s spores to be dispersed by wind. If spores land in a place with favorable conditions, including favorable moisture and temperature, they will germinate.
Gametophyte
- Unlike the seed of a flowering plant, the wood fern spore does not grow directly into the mature plant after germination. Instead, the spore gives rise to a stage in the wood fern̵7;s life cycle that botanists call the ̶0;gametophyte.̶1; The gametophyte is a small, obscure, more or less heart-shaped structure growing in close contact with the ground; it looks not at all like the mature fern. The gametophyte features small male and female structures. The male structures produce sperm, and the female structures, eggs. Under the right conditions, sperm will swim to the eggs ̵2; possibly to the eggs of a gametophyte from a different individual wood fern ̵2; and fertilize them.
Maturation
- Once fertilized, the egg develops into a wood fern embryo. The embryo, while still attached to the gametophyte and gaining nourishment from it, grows into a small wood fern ̵2; a new sporophyte. The small sporophyte continues to grow, eventually taking on the familiar appearance of the mature wood fern. Once fully grown ̵2; and complete with rootstock, frond and sori containing mature spores ready for release ̵2; the wood fern has completed its life cycle.

Nature