During the last few weeks our forests have gone through a dramatic change. Seen from afar, that has been obvious in the changing of leaf colors and the thinning out of the leaves in the tree canopies. Walking inside the forest, these processes are reflected by the thick layer of color-full fallen leaves and surprising new views through leaf-less branches. Flowering or even just green plants on the forest floor have become a rare sight.
This is the season when we tend to notice the abundance of ferns in our forests. Over all, we know of 65 species of ferns and fern relatives (such as club mosses and horsetails) in Columbia County and have found around 15 of them on Phudd Hill. This little photo essay is not trying to represent all of the species that occur on Phudd Hill, but just to highlight a few that can be observed right now.
We have both evergreen and deciduous ferns. In this picture, the evergreen Christmas fern (Polystichum acrostichoides) contrasts with the withering, yellow fronds of hay-scented fern (Dennstaedtia punctilobula).
Christmas fern is one of our coarser-leaved ferns, its leaflets (or “pinnae”) are not dissected, but have a characteristic assymetrical base with a little “ear” near the fronds midrib (or “rachis”).
The spores of Christmas fern are formed on the underside of the leaflets at the tip of the frond and the sori (small clusters of spore-producing structures) tend to cover the entire blade of those leaflets. Both these close-up photos were taken in the native plant garden at the Creekhouse.
Superficially similar to the Christmas fern is another coarse-leaved evergreen fern, the common polypody (Polypodium virginianum).
Note how the leaflets of common polypody line up seamlessly along the midrib and do not have the “ears” characteristic of Christmas fern. Common polypody tends to be smaller than Christmas fern and is usually only found on or near rocks or at the base of trees.
Another evergreen fern that draws our attention during this season is the marginal woodfern (Dryopteris marginalis). It tends to be a large fern with fronds that form orderly, vase-shaped clusters.
Its leaflets (or “pinnae”) are dissected into “pinnules” and the spores are produced on the underside of most leaflets. The round sori (clusters of spore-producing structures) are located very close to the margin of the pinnules, hence the name “marginal” woodfern.
Sensitive fern (Onoclea sensibilis) is the first fern to wither after a good frost. This picture was taken 10 days ago. Can you still find any green sensitive ferns in frost-protected micro-habitats?
Sensitive fern is a very common fern of wet meadows and swamp forests, but can also be found near vernal pools and other wet areas on Phudd Hill. In a few spots it is joined by another wetland fern, the much rarer royal fern (Osmunda regalis).
Finally, here comes one of my favorites, the easily recognized and beautiful maidenhair fern (Adiantum pedatum). It is an uncommon plant Columbia County and likes calcium-rich soils. On Phudd Hill, we know of only one spot with a few individuals of this species. This photo was taken in the native plant garden at the Creekhouse.
Maidenhair fern has thin, polished, dark purple to black stems and its exotic-looking fronds fit with the fact that it is a member of a tropical genus, with many close relatives growing in the rainforests of South America.
On our way to Phudd Hill, last week, we found another member of a tropical genus stranded on a cold and windy day in the dairy field of Hawthorne Valley Farm.
The common buckeye (Junonia coenia) is a medium-sized butterfly (wingspan: 2″) and the only member of a tropical genus that regularly migrates north. Depending on the year, they may or may not make it into Columbia County. This year, Conrad and other butterfly observers have seen unusual numbers of this beauty in the County.
I felt very privileged to stumble upon this one, obviously freshly emerged (no sign of wear, whatsoever), and too cold to fly away when I came close with the camera… Will it be able to make it back south for over-wintering???