Ferns

Under favorable conditions, a spore "germinates" and grows into a heart-shaped little plant, called the prothallium. This tiny plant is the sexual generation of a fern (gametophyte).

The underside of the prothallium bears tiny male and female organs producing sperms and eggs. At high moisture, the sperm swims over the leaf surface to the female organ (archegonium) and fertilizes the egg.

Fern Biology:
sporophyte of a fern, growing in a crevice	Ferns don't have flowers and don't produce seeds. Instead, they have a special life cycle with alternating generations of spore-producing plants (sporophytes) and sexual plants (gametophytes). What we usually see of a fern is the sporopyte, which produces spores on the undersides of the fronds (fern leaves), or on specially modified leaves, such as visible at the Cinnamon Fern.
On the underside of the front of a sporophyte (Humata tyermannii) are located the sori with sporangia, where spores are produced	The spores are produced in tiny sacks called sporangia. The sporangia are clustered together into sori. The photo on the right shows sori (clusters of sporangia) located on the underside of a fern frond, with the sporangia (little round brown balls) on the inside. The dust on the photo are not spores but sporangia that popped open and fell out of the sori. The transparent skin covering the sori is called indusium. (this species is ). (photos taken with a Nikon Coolpix P50 hand-held through the lens of my old Eschenbach Stereo Microscope at 10x and 20x magnification)
The gametophyte of a fern, called prothallium (growing in my non-sterilized rhododendron rooting tray)	Under favorable conditions, a spore "germinates" and grows into a heart-shaped little plant, called the prothallium. This tiny plant is the sexual generation of a fern (gametophyte). The underside of the prothallium bears tiny male and female organs producing sperms and eggs. At high moisture, the sperm swims over the leaf surface to the female organ (archegonium) and fertilizes the egg.
A young sporophyte is growing from the underside of the prothallium	The archegoniae on the underside of the prothallium are tiny. Click the photo to see an enlargement; the archegoniae are whitish dots! After fertilization, the egg develops into a new plant, a sporophyte (the typical fern plant, see first photo), which grows out from under the prothallium, where the archegonium is located.
	Horsetails are closely related to ferns (here Equisetum hiemale). The spores are formed in special organs that look like pale and narrow pinecones (photo coming later)
	Mosses are also plants that produce spores. However, the life cycle is slightly different: The small, low-growing green plant that we usually recognize as a moss is the gametophyte. On the tip of the gametophyte grows a second plant, which looks like a little flower on a stem. This is the sporophyte, with the spore capsules on the top. With the mosses, the sporophyte can not form an independent plant.
Fern species and varieties:
	Maidenhair fern (Adiantum pedatum) has a wonderful texture and an interesting habit. The fronds are sitting high on slender stalks and curve elegantly like a Maiden's hair! It is a beautiful, native New England fern that can enrich every shade garden. It thrives in rich soil and loves lime.
Maidenhair spleenwort (Asplenium trichomanes)	Spleenwort is not suitable for ordinary garden culture. It needs very strong drainage and lime. Use in rock gardens in part shade or full shade, and protected from drying winds.
Lady fern (Athyrium filix-femina 'Lady in Red')	This Lady Fern has reddish stalks. It is a selection of our native Lady fern and an excellent, easy to cultivate native species. All Ferns need soil that is rich in organic matter.
Japanese Painted Fern (Athyrium nipponicum 'Pictum') is a beautiful garden fern from Japan.	Developmental stage, soil and light conditions influence the color of the fronds.

	Athyrium 'Ghost' is paler in coloration than Japanese Painted Fern, and it grows much taller.

	Hayscented Fern (Dennstaedtia punctilobula) is a rapidly spreading fern that can be used as a groundcover on slopes in full sun or shade. It is probably a good plant for erosion control, but keep it away from garden beds where it will be hard to control.
	Ostrich Fern (Matteucia struthiopteris) is a very large fern that likes rich, moist or wet soil. Under perfect conditions, it can grow more than 6 ft. tall.