A Few Statistics, Illustrated

Depending on when you look it up, and the current state of research, and the seeming whim of taxonomists, the Asteraceae is the largest plant family on Earth, with 23,000 species (more or less).  Only the orchid family is as large, or larger, maybe.  Species in the Asteraceae can be found in almost every habitat, on every continent except Antarctica.

20140518-DSC_0092 Erigeron philadelphicus (common fleabane)





In the Potomac Gorge area, I’ve found more plants in the Asteraceae than any other family, by far: seventy species. That’s out of a total of 351, or just shy of 1 in 5.  This includes the asters themselves, the beggar-ticks, bonesets, coneflowers, coreopsis, dandelions, elephant’s foot, everlasting, the various fleabanes, the multitudes of goldenrods, leafcup, hawkweeds, horseweeds, ironweed, fireweed, rattlesnake weed and ragweed and ragwort, pussytoes, snakeroots and sneezeweed, sunflowers and thistles, and wingstem. And some aliens I didn’t bother to name.


The second largest family, at 21 species (13 native, 8 alien), was the Fabaceae (pea family).

Lespedeza virginica (slender bush-clover)







In third place was the Lamiaceae (mint family) at 16 (11 native, 5 alien).

Scutellaria elliptica (hairy skullcap)






lyre-leaved rock-cress

Brassicaeae (mustard family) checked in at 15 (7 and 8).

 Arabis lyrata (lyre-leaved rock cress)




rue anemone duo


Ranunculaceae (buttercup family) had 14 (10 and 4).

Thalictrum thalictroides (rue-anemone)



swamp dewberry


The Rosaceae (rose family) had 12 (9 and 3).

Rubus hispidus (swamp dewberry)



sweet cicely closeup 2


And the Apiaceae had 10 (6 and 4).

Osmorhiza longistylis (aniseroot)





And though the Orchidaceae is so large worldwide, in this area I found only two. More on that tomorrow.

Tipularia discolor (cranefly orchid)




Here’s a nice tutorial on the Asteraceae.

Flower of the Day: Horse Balm

Collinsonia canadensis; Lamiaceae (mint family)

20140807-DSC_0111  20140807-DSC_0112

The Cabin John Trail irritates me.  It’s overused and in poor condition, treacherous when wet, sometimes smelling from the sewer main it follows… and yet I’ve found some great plants there.  On August 7 I walked along the stream looking for goatsbeard (FOTD June 9), wanting to see what it looked like in seed (still pretty impressive), when I spied something else growing out of the rocks over the creek.  Something I’d never seen before, or even heard of.

I love when that happens.

Horse balm is a big plant, growing to five feet tall and three feet across.


The leaves have a pleasant scent (as so many mints do); the plant was used medicinally by Native Americans and settlers.  It’s native to eastern US and Canada, and endangered in Wisconsin.

Here’s what the goatsbeard looked like, by the way:


Flower of the Day: Narrow-Leaved Mountain Mint

Pycnanthmum tenuifolium; Lamiaceae (mint family)


I’d been keeping my eye on this plant for weeks, watching the buds develop. When I finally saw a few of the flowers open, I set up the tripod and spent at least half an hour trying to get good pictures.  The plants were in the open, but on a partly cloudy day with a fair breeze.  As soon as I thought I had the camera set up for the light, the breeze would set the plants moving.  And whenever the breeze stopped, the light had changed.

So I went back seven days later, expecting the plants to be in full bloom.  And guess what I found: nothing.  Nothing except a lot of dead plants, because some overly enthusiastic trail maintenance people had come along and mowed the whole patch down (there were other native plants there, too).  And it wasn’t necessary.  This was along a rocky bluff, and the plants were on a ledge a few feet off the trail proper.  This area, with a huge diversity of plants, has been subjected to multiple floods this year, and it shows: there are fewer plants, and those that survived are stunted or in poor condition, and some have been missing altogether.  And now this happens.

I’m just livid.  This is the only stand of narrow-leaved mountain mint I’ve ever seen, and now it is utterly gone.  Thankfully it’s a perennial, so it should be back next year.

The flowers you see in the picture above are so tiny that the purple dots are invisible to the naked eye.  Here’s a picture of several flower clusters, each of which is about fingernail sized:


The abundant, dark green linear leaves give the plant a fine-textured appearance:

20140613-DSC_0166-1It would be a lovely addition to a native plant garden.

Pycnanthemum species can be found throughout the eastern US and Canada; seven species occur in Maryland.  I have my eye on another one in bud.  It might be hoary mountain mint.