A Drier Place, Two Not-So-Big Ferns

In the drier (but still moist) woodlands towards the top of Sugarloaf Mountain you can find more species of ferns, not as big as the ones I posted about last time. Both these species are light-colored and medium-sized, and both will form large colonies.


New York fern
Thelypteris noveboracensis


New York fern’s distinguishing characteristic is the shape of the blade, which tapers at both ends.


Each pinna is deeply lobed, but not cut all the way to the costa (midrib). Note that the rachis, costa, and pinnae are smooth (as opposed to hay-scented fern below).




a good-sized colony of New York fern about halfway up Sugarloaf Mountain

New York fern ranges from Oklahoma and Louisiana east and north up into Quebec and Newfoundland. It’s endangered in Illinois and exploitably vulnerable in New York.






hay-scented fern
Dennstaedtia punctilobula

The blade of hay-scented fern is 2 pinnate-pinnatifid (meaning twice cut, the pinnules deeply lobed but not cut all the way to the costa).



If you zoom in you can see fine hairs on the rachis, costa, and pinnules.


forest floor carpeted with hay-scented fern

Hay-scented fern ranges from Missouri and Arkansas east to the Atlantic and north into Canada. It’s endangered in Illinois and possibly extirpated in Michigan.

One Wet Place, Three Big Ferns


cinnamon fern
Osmundastrum cinnanomeum

A small stream called Bear Branch, a tributary of Bennett Creek (which is a tributary of the Monocacy River) flows through the Sugarloaf Mountain Natural Area. It’s a nice place to go botanizing, despite some pretty heavy deer browse. The understory is full of mountain laurel (Kalmia latifolia). I’m slightly embarrassed to say that I’m not sure of the canopy; chestnut oak mostly, and some beech, but I have a bad habit of looking down when I should be looking all around.

Anyway, the more or less flat area where the two forks of Bear Branch meet, by Mt. Ephraim Road, is almost swampy. Last month I noted many croziers coming up there, but I don’t know ferns well enough to identify them by their fiddleheads. By last week most were fully opened into tall fronds, and some had fertile fronds as well. Fertile fronds make identification much easier.

All three of these species are in the Osmundaceae. All three have similar ranges, mostly east of the Mississippi River as far south as Georgia and north well into Canada (cinnamon fern ranges further into the southwest). All three are tall, clump-forming ferns of wet places, and all three have distinctive fertile fronds.

(Apologies for all the jargon in this post. Have a look here and here for some definitions.)


a young royal fern; fronds can grow to 3 feet in length

royal fern
Osmunda regalis var. spectabilis 

Royal fern has an unusual look. The pinules of the bi-pinnate fronds are simply-shaped and widely spaced along the costa, giving the frond an open, airy appearance.


pinules (leaflets) along the costa (midrib)



portion of a blade showing bi-pinnate form







closer look at clumps of sporangia on fertile frond





Royal fern is commercially exploited in Florida, threatened in Iowa, and exploitably vulnerable in New York.











cinnamon fern
Osmundastrum cinnamomeum
(formerly Osmunda cinnamomeum)

When fertile fronds are present, cinnamon fern can’t be mistaken for anything else. You can see how it gets its common name (and specific epithet) from the fertile fronds, borne separately from the sterile fronds; when mature, the sporangia turn brown, giving the look of a cinnamon stick.


the leafy, sterile fronds are pinnate-pinnatifid, meaning the blade is once cut into pinnae, and each pinna is lobed but not cut all the way to the costa (midrib)

Cinnamon fern is commercially exploited in Florida, endangered in Iowa, and exploitably vulnerable in New York. It’s commonly available in the nursery trade, and is a great landscaping plant for a large, shady, wet part of the yard.






interrupted fern
Osmunda claytoniana

As with cinnamon fern, the fertile fronds of interrupted fern make identification easy, and you can see how it gets its name. The sporangia (green when young, tan or brown when mature) cluster on the rachis between the pinnae.  This fern likes wet places, but not as wet as the previous two. Each species I found growing in distinct stands in the same general area, but well apart from each other. The interrupted fern was significantly further uphill, on a bit of a slope in a slightly rockier area.


clusters of mature sporangia “interrupting” the pinnae along the rachis

Interrupted fern has pinnate-pinnatifid blades. It’s threatened in Arkansas and exploitably vulnerable in New York.


a single pinna, showing pinnatifid form (pinnules not cut all the way to the costa)



It’s a good time of year to be watching for emerging fiddleheads, also called croziers. Here’s a random assortment of some I’ve found, including several that I haven’t identified; that will probably have to wait for fertile fronds to emerge later in the year.


I just love this one; it looks like a dragon or alien monster or something.  This fern is all over the place at Sugarloaf Mountain and Rachel Carson Conservation Park; I expect it’s one of the Dryopteras. It is not one of the evergreen ferns.


Christmas fern (Polystichum acrostichoides), below, is easily identified because it’s so hairy.



Another unknown (right and below); I’ve been seeing it in wet areas in parts of Montgomery County other than the Potomac Gorge.



Right, one of my favorites: ebony spleenwort (Asplenium platyneuron). Below, a forefinger held up to the same plant.20160405-_DSC0163


And this one (right) was a good find. It’s the fertile frond of a rattlesnake fern (Botrypus virginianus), which I’ve only seen once before. You can see the spherical sori contained within. This plant was in Rachel Carson Conservation Park, where I went to see the pinxter azaleas in bloom. (More on that in a few days.) Below is a picture from last year, showing the fully developed fertile frond.


Carderock Area Update for Early April


azure bluets
Houstonia caerulea

Everything that was blooming last week is still blooming, except that spicebush is nearly done, and leatherwood is done.

Seen yesterday around Carderock:

  • spring beauty
  • cut-leaved toothwort
  • Virginia bluebells
  • Dutchman’s breeches
  • trout lily
  • toadshade
  • redbud
  • lyre-leaved rock cress
  • smooth rock cress
  • rue anemone
  • azure bluets
  • kidney-leaved buttercup
  • field chickweed
  • star chickweed
  • wild blue phlox
  • golden ragwort
  • early saxifrage
  • blue violets
  • yellow violets


Newly blooming:

  • jack in the pulpit
  • sweet cicely (way early!)
  • sessile bellwort [thanks, LW!]
  • swamp buttercup (left)
  • wild pink (below)






Also, I think I’ve identified a plant I saw last week near the Marsden Tract. It’s a Cardamine species, probably spring cress, C. bulbosa. That doesn’t happen often anymore!


And, in non-flowering plant news, new croziers are popping out on Christmas fern (above) and rock polypody (below, growing out of moss next to lichens).


Peripheral, But Not Insignificant


marginal wood fern, marginal shield fern, leather fern
Dryopteris marginalis

beautiful specimen near Snyder’s Landing, June 2015


While out looking for something green (other than Christmas fern and rock polypody), I found marginal wood fern.  “Marginal” not because it’s insignificant, but because the sori are located along the margins of the pinnules.



sori along the edges of the pinnules


Marginal wood fern is widespread across the eastern US and Canada, except in Iowa and Minnesota, where it’s threatened.  New York lists it as exploitably vulnerable.



scaly stipes


Like so many ferns, it likes a damp habitat.  In the Maryland Piedmont look for it in ravines and rocky slopes.  I found dozens of them clambering over cliffs at the edge of Cabin John Creek, in an area that’s always wet from seeping groundwater.



groovy – er, grooved – rachis