Common Interrupted-clubmoss (Spinulum annotinum) is a spore-bearing vascular plant who grows in forests throughout much of New England. This plant creeps by horizontal stems that often hide just below the leaf litter. Upright stems are ~6" tall; often branched near the base; crowded with narrow, bristle-tipped leaves (another common name for this species is Bristly Clubmoss); and have noticeable interruptions that indicate where one year's growth ended and the next began. Each fertile branch is topped with a stalkless, solitary, 1-1.5" long cone-like reproductive structure, called a strobilus.
This green season, I've made a habit of checking on a population of Virginia Chain Fern (Woodwardia virginica) every time I visit the local bog, and in late September the patch was dressed in rusty colors of early autumn senescence. Virginia Chain Fern is a specialist of bogs and other acidic wetlands and grows in all six New England states. Individual fronds are fairly tall (2-4') and may call to mind the sterile fronds of Cinnamon Fern. However, unlike Cinnamon Fern, Virginia Chain Fern doesn't grow in circular clumps or have tufts of woolly hairs along the stalk, and the two ferns have different vein patterns (see comparison photo below). (To view the following images in full-size, click here.)
Once you've stored a few search images in your mind's eye, Sensitive Fern (Onoclea sensibilis) can be spotted nearly year-round, the exception being if there is deep snow pack, like we had the winter of 2014-15. During the green season, look for this fern's distinctly lobed blades. After a frost kills back these sterile fronds, looks for the thin, brown-topped fertile fronds, which stand as convenient flags for fern observers. The fertile fronds persist throughout the white season to release their spores in spring. Sensitive Fern is often found in wetlands, like swamps, and on the edges of ponds and streams. (To view the following images in full-size, click here.)
Southern Ground-cedar (Diphasiastrum digitatum) is another spore-bearing evergreen clubmoss who grows on forest floors. The plants are only a few inches tall and are connected by horizontal above-ground stems to form groups, though the plants are not always found in neat rows like in the above photo.
The shiny, flattened branches are arranged in fan-like sprays. The spore-bearing reproductive parts -- called strobili -- grow on thin, branched stalks that extend well above the leaves.
Like true ferns, fern allies are vascular plants who produce spores rather than flowers and seeds. One of the more common types in New England is Flat-branched Tree-clubmoss (Dendrolycopodium obscurum), referred to by many as Princess-pine or Ground-pine. This plant grows rather slowly, so while you might be tempted to gather a bunch to use as handsome holiday decorations, I recommend allowing them to retain their evergreen, ankle-high niche on the forest floor. There you can enjoy them year-round.