This Just In

Remember the long, detailed post I wrote the other day about ferns? that went on about taxonomy?  Forget about it.

As reported in Science News, “kingdoms are so 20th century when it comes to the main evolutionary branches of the tree of life.”  It’s an interesting article if you like this sort of thing.


here’s a rosemallow, just because

Fern Morphology and Terminology: an Illustrated Guide

purple-stem cliffbrake (Pellaea atropurpurea) and maidenhair spleenwort (Asplenium trichomanes) growing together from a crevice in a wall

It’s been said that botany is the study of terminology.  Ferns have a language all their own (mostly).  Here’s a little primer on how ferns are structured and described.

A fern consists of a rhizome (a horizontal underground stem), with roots below and fronds above.

The frond is the entire “stem and leaf” arising from the rhizome.20150724-20150724-_DSC0080


fertile frond of christmas fern (Polystichum acrostichoides)




The frond consists of a stipe, blade, rachis, and pinnae.

The stipe is the portion of the stem from ground level to the lowest pinna (analogous to the petiole of a flowering plant).20150724-20150724-_DSC0080-3


the highlighted portion is the stipe




The blade is the portion of the frond carrying the leafy tissue (analogous to the leaf of a flowering plant).20150724-20150724-_DSC0080-2


everything except the stipe is the blade




The rachis is the midrib portion of the stem within the blade, and the pinnae (singular pinna) are the green parts of the frond (analogous to the leaflets of a compound leaf).20150724-20150724-_DSC0080


a single pinna highlighted; the pinnae are attached to the rachis



In twice cut (bipinnate) ferns, the pinnae are further divided into pinnules (sub-leaflets).20150724-20150724-_DSC0089-2


a single pinna with pinnules




In thrice cut (tripinnate) ferns, the pinnules are divided into pinnulets (sorry, no pictures!).

There’s terminology for blade shapes, too.  An undivided blade is simple.20150730-20150730-_DSC0350


a frond of walking fern (Asplenium rhizophyllum)




A blade with divisions reaching all the way to the rachis is pinnate (once-cut).


a blade of maidenhair spleenwort (Asplenium trichomanes)




If each pinna is further divided all the way to the midrib, the blade is bi-pinnate.20150724-20150724-_DSC0086


a blade of marginal wood fern (Dryopteris marginalis)




If each pinnule is further divided all the way, the blade is tri-pinnate (again, no picture).

A blade with divisions not reaching all the way to the rachis is pinnatifid:


a frond of common polypody (Polypodium virginianum)




These terms can exist in combination.  This broad beech fern (Phegopteris hexagonoptera) is pinnate-pinnatafid according to one authority,20150724-20150724-_DSC0091

but it sure looks bi-pinnatafid to me:20150724-20150724-_DSC0096






Next time, a look at some fertile fronds.

Variations on a Theme: Monkeyflowers


Mimulus ringens (Allegheny monkeyflower)
Mimulus alatus (winged monkeyflower)

There are about 90 species of monkeyflowers in the US and Canada, but almost all of them are confined to the western part of the continent.  Five are found east of the Missiissippi, and of those, only two are known in Maryland.

Which one is pictured above?  That’s winged monkeyflower, but you can’t quite tell from the picture.  The flowers are almost identical, though in different parts of the country there can be marked color differences.


The Allegheny monkeyflower has sessile leaves (meaning the leaf base touches the stem), while the flowers are connected to the stem by a long pedicel.



Both species can grow up to 3 feet tall, and both have the same cultural requirements: wet or at least consistently moist soils, and some shade.  The sorry-looking specimen shown here was growing in a very interesting place (perhaps subject of a future blog post), in full sun.  All of the plants (there were only a few) were stunted.


Winged monkeyflower is the opposite of the other with respect to how the leaves and flowers connect to the stem. In this species, the flowers are sessile or almost sessile, while the leaves have longed winged petioles (and winged stems).

The winged monkeyflower has some conservation issues: special concern in Connecticut, threatened in Iowa, endangered in Massachusetts, probably extirpated in Michigan, and rare in New York.

20150724-20150724-_DSC0035nice, tall plants in part shade along the river


UPDATE: the genus Mimulus is now placed in the Phrymaceae

Once Turned, Under the Pines


aka false beechdrops, yellow bird’s-nest
Monotropa hypopitys


On a recent nice evening I talked Steve into going for a walk with me to look for certain ferns.  He agreed to go when I promised not to take my camera.  This is sort of a left-handed good luck tactic, as I seldom fail to find something interesting when I don’t have my camera handy.

It worked: we found this tiny stand of pinesap on a hillside above the trail.  I took a few crappy iPhone pics, which later served as a guide, since I was able to look at the geotag and find the stand again, this time with camera and tripod but sans Steve.


As I wrote about Indian pipe last month, the Monotropas aren’t actually saprophytes; they get nutrients by parastizing certain fungi that form a symbiotic relationship with certain trees.  As such, they have very specific growing requirements, and are somewhat rare within their range.

“Once turned, under the pines” is a literal translation of the botanical name of this plant, which is found throughout the US and Canada except for four states and the extreme north.  While researching I found that ITIS* does not recognize the species name, and instead reverses the genus and specific epithet, calling it Hypopitys monotropa.  This is probably based on genetic studies, as so many recent taxonomic reclassifications are.

Pinesap is endangered in Florida and threatened in Iowa.


*the Integrated Taxonomic Information System, about which I wrote yesterday