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: Butterfly Pea

aka Atlantic pigeonwings*; Clitoria mariana; Fabaceae (pea family)

*or, possibly, “Maryland lady-parts”


The same day I found culver’s root while scrambling about on rocks, I found this plant.  It, too, was climbing over rocks.  It’s a vine, liking rocky habitats and sunlight.  Though I found several plants, I only found the one flower (and two days later, still only one flower).  It grows throughout the eastern US through the Great Plains and the desert southwest, but is endangered in New Jersey and Pennsylvania.  Only one other natives species of Clitoria grows in the US, and that only in Florida.

About the genus name… I know what you’re thinking, and you’re right.  First described by a German botanist in 1678.  I thought maybe “mariana” was his girlfriend, which is dubiously romantic.  “Honey, I named a flower after you.”  But according to several different sources, the specific epithet “mariana” means “of Maryland”. So you could also call this flower “Maryland lady parts”.  As a Maryland native I’m not sure how I feel about that.

Apparently over the years botanists have been offended by the genus name and have tried to change it; Wikipedia has a nice little discussion on the topic..

Flower of the Day: Naked-Flowered Ticktrefoil

 Desmodium nudiflorum; Fabaceae (pea family)


Plants in the Fabaceae are not my favorites, maybe because there are a lot of ugly, invasive aliens in that family.  But I did a double-take when I saw this one.  Isn’t it gorgeous?


Not like the typical scrawny sprawling messy plants that I’m seeing all over the area this time of year.  Naked-flowered ticktrefoil has one short stem of large compound leaves standing at about six inches , and another stem (leafless) bearing a panicle of flowers, about two feet up.

By the way the leaves in the picture above have dried sand from a nearby trail all over them.  I searched the immediate area for more (cleaner) plants to photograph, but this was the only one I could find.

There are 42 native species of ticktrefolis in the continental US.  This one ranges throughout the east and parts of the prairie midlands.  Apparently the name “ticktrefoil” derives from the fact that the seeds have tiny hooks, allowing them to stick like a tick to any passing animal; “trefoil” indicates a 3-leaved (or in this case, leaflet) plant.