This is Why We Hate Invasives

Last summer I was tickled to discover eleven new (to me) species of wildflowers growing along the Potomac between Fletcher’s Cove and Chain Bridge. These weren’t little bitty plants, either – most were big and showy. So yesterday I went back and hiked the river trail from Fletcher’s to a point within view of Chain Bridge – about six-tenths of a mile.  And this is what I saw:

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It’s forgivable if you find it pretty, but to a native plant enthusiast it’s a horror show, a textbook example of the danger of alien invasive species. It’s lesser celandine, aka fig buttercup (Ranunculus ficaria, previously Ficaria verna, Ranunculaceae), one of the worst invasives in the area. And you can see why from the picture. Strictly speaking, that isn’t a monoculture, as I did find other species in there: henbit and some purple deadnettle (also alien invasives), with a few spring beauties popping through. And, near Chain Bridge, I saw a single clump of field chickweed.

Try to imagine this. The area is a floodplain about one-tenth of a mile wide (from the river to the slope up to the canal towpath) by at least six-tenths of a mile long, and the whole thing is predominately one species.

This is why we hate invasives. Not because they’re alien per se, but because they can overcome everything. Imagine what this might have look liked a few decades ago: a carpet of Virginia Bluebells giving way up-slope to trout lilies, Dutchman’s breeches, spring beauties, and cut-leaved toothwort.

It makes me a little sick.

End of March Update for the Potomac Gorge

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lyre-leaved rock cress, in its favorite place

 

 

It’s a strange season. Lots of different plants are blooming, but not in the vast quantities I would expect. Several species are blooming rather early, or very early, like a full two weeks sooner than last year (not unexpected given a very warm autumn and winter).

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star chickweed
quiz: how many petals are on this flower? (answer below)

 

 

On Monday, March 28, harbinger-of-spring was done. Otherwise, the plants I reported on last week are still going, and nothing has hit its peak yet.  To that list add

…quiz answer: five; each of the petals is deeply divided into two lobes, so that a single petal appears to be two

Belly Daisies

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desert star; Mojave desertstar
Monoptilon bellioides

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rock daisy; Emory’s rockdaisy
Perityle emoryi

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woolly daisy; easterbonnets
Eriophyllum wallacei
(formerly Antheropeas wallacei)

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false woolly daisy; yellowray Fremont’s gold
Syntrichopappus fremontii

 

 

These four Death Valley belly flowers are in the Asteraceae, of course. All are native to the desert Southwest. All are itty-bitty (note the penny in the first photo above).

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I found desert star to be especially charming.

 

young blossoms just opening

 

 

 

mature blossom

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rock daisy is about the size of a pinky-nail

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woolly daisy is about the same size

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yellowray Fremont’s-gold is a smidge larger (that’s a forefinger nail)

 

 

And a special bonus bellyflower: can you see the purple blossom in the upper right of the above photo? The whole thing is about the size of one of the yellow rays. It’s called salt sandspurry (Spergularia salina; Caryophyllaceae). I didn’t even know it was there until I looked at the picture!

 

How Plants Grow in the Desert

I am no expert in wildflowers, especially not in desert wildflowers, but some things are obvious. Like, even desert plants need water. Take a look at this picture:

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If you can, click to zoom in. How many plants do you see? How many different species? Notice how they’re all growing together in the lee of a small group of rocks.

I did a lot of poking about during my two and a half days in Death Valley, and it took no time at all to figure out that if you want to see wildflowers (beyond the fields of desert gold), you need to go where there’s moisture in the ground. On the shady side of a wash, up a narrow canyon, into gullies and gulches.

I have nothing special to say about this except that I love the tenacity of desert plants.

…oh, the answers: six plants, five different species. In the lower left
Chylismia claviformis ssp. claviformis (brown-eyed evening-primrose), Cryptantha muricata (pointed cryptantha), Phacelia calthifolia (caltha-leaved phacelia), and Aliciella latifolia ssp. latifolia (broad-leaved gilia). In the upper right, Cryptantha muricata and Geraea canescens (desert gold).