Ebony Spleenwort



Asplenium platyneuron
new fronds with croziers, May 2015


The day after my last post, I went to Hoyles Mill Conservation Park (in the Little Seneca Creek watershed, near Boyds), hoping to find some evergreen ferns. There was a nice stand of Christmas fern along a bank:


Looking closer I saw a second species: ebony spleenwort.  It’s the smaller, lighter-colored fronds on the left in this picture:


At twelve to twenty inches tall, ebony spleenwort is one of the larger members of its genus.  It’s wide-ranging, from Quebec south and west as far as Arizona, and can be found in a variety of habitats.  Look for it on embankments, rock outcroppings that have a little soil, even old stone fences.  It’s listed as special concern in Maine and exploitably vulnerable in New York.



a specimen near C&O Canal lock 8, August 2015




The name “asplenium” is from the Latin, meaning “without spleen”.  The specific epithet “platyneuron” can be translated as “flat-nerved”.


underside of a pinna on a fertile frond, showing indusia and sporangia



Several other evergreen ferns can be found in the Maryland Piedmont; I’ll be posting about them in the coming weeks.

Oh, Christmas Fern


Polystichum acrostichoides
Dryopteridaceae (wood fern family)

specimen showing sterile and fertile fronds; pardon the boot!

If you’ve been walking around the woods during this freakishly warm season, you’ve probably seen Christmas fern, a widespread evergreen fern of moist to dry woodlands that’s found all over the eastern part of North America.  It’s a lovely plant for the garden, with glossy dark fronds adding winter interest, and a tidy, clump-forming habit.



young frond in July




Christmas fern stands about two feet tall, and is easily identified (especially in winter). Each pinna has a distinctive upward-pointing lobe near the base, variously described as a thumb, or toe, or ear. (The technical term is auricle, meaning ear-shaped lobe.)

The fertile fronds have a distinctive shape, with the sori-bearing pinna becoming shorter, narrower, and more widely spaced on the upper portion of the fronds:









sori on underside







crozier in July



ps: please refer to my posts about fern terminology and fertile fronds for definitions of some of the jargon

Three Views

And here’s the final view for 2015, after a few days of rain. Don’t forget to visit the Three Views page to see how things change month-by-month.

December 4
41 degrees F at 9:40 am; sunny 


9: 54 am EDT  31mm  f/8.0  1/250sec  ISO 100

Billy Goat B trail, east end, looking southeast across a narrow channel toward Vaso Island


11:11 am EDT  30mm  f/10  1/100sec  ISO 100

Billy Goat B, mid-way between trailheads, looking upstream (more or less northwest) with Hermit Island on the left.


11:45 am EDT  28mm  f/8.0  1/640sec  ISO 100

boat launch ramp near Old Angers Inn, looking downstream and more or less south