Braking for Wildflowers Again


Steve and I were in Joshua Tree National Park recently. There wasn’t a super bloom this year, but there were still a few wildflowers. Mostly they were the Sonoran and Mojave desert plants that I wrote about this time last year, and the year before that.

Heading south on Pinto Basin Road toward the Cholla Garden, I spotted large, dark green leaves on plants growing by the side of the road. What the heck, is that datura? I thought. Then, “Steve, slow down!”

And he did, and pulled over, and I jumped out and had a look.

Yes, they were Datura, but all the flowers were spent or closed. So the next day we went back, and drove slowly (whenever no cars were behind) until I spotted some open flowers. And he pulled over again, and had a little catnap in the car while I got on my belly on the sandy roadside shoulder and snapped some pictures.


There are two species of datura in JOTR, D. wrightii (sacred thorn-apple) and D. discolor (desert thorn-apple). This one is the former. Other common names for the various Datura species include jimsonweed and angel’s trumpet; there are dozens more, including moon lily, moon flower, belladonna, devil’s trumpet, deadly nightshade, thorn apple, mad apple, hairy jimson weed, stink weed, green dragon and locoweed1, and toluaca2.

These spectacular flowers measure about 15 cm long, and the plants can grow to a meter or more tall and almost two meters wide. All parts of the plants are poisonous, not unusual for plants in the Solanaceae.

The Solanaceae, like the Apiaceae (see Tasty Umbellifers and Poisonous Umbellifers), is notable for producing both foods (eg, tomato, potato, chili pepper, and eggplant) and poisons (eg, belladonna, tobacco, mandrake, and henbane).

We have a datura here in the Maryland piedmont, D. stramonium [right], but it’s an invasive alien that can form large, nearly monocultural stands. There’s an especially bad infestation on an islet in the Potomac just upstream of the American Legion bridge [below].


1DesertUSA
2Calflora

Odds and Ends

Two more plants I found blooming in Death Valley. At first I found neither of them interesting, but the more I read – or the more closely I looked – the more I liked them.

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sticky ringstem, valley ringstem
Anulocaulis annulatus
Nyctaginaceae

This plant is endemic to the Mojave desert. It’s a perennial with a shrub-like growth habit. The flowers are quite small; you really have to zoom in to see them.

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yellow nightshade groundcherry
Physalis crassifolia
Solanaceae

There are several plants producing edible fruits in the genus Physalis: tomatillo and Cape gooseberry. Also “groundcherry”, which I’ve seen on menus (and my plate) in trendy restaurants, but I’d hesitate to say that this particular groundcherry is one of the edible ones. As with the Apiaceae, the Solanaceae (deadly nightshade family) has some tasty, culinarily important species as well as poisonous ones.

This range of P. crassifolia is limited to the desert southwest. Like sticky ringstem, it’s a perennial with a shrub-like growth habit.

Have a look at this abstract from the Journal of Natural Products; it seems that P. crassifolia can produce compounds showing “potent antiproliferative activity” that may some day be used for treating certain cancers.

 

Flower of the Day: Hairy Wild Petunia

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aka Carolina wild petunia
Ruellia caroliniensis
Acanthaceae

 

 

 

Despite the common name, and despite appearances, this plant is more closely related to water willow (FotD June 20) than to the common garden petunia.  The latter plant is in the genus Petunia, family Solanaceae, and is therefore closely related to tobacco and tomatoes.

Actually Ruellia and Petunia are quite far apart taxonomically; not only are they in different families,  they’re in different orders (Scrophulariales and Solanales, respectively).

About 15 species of Ruellia can be found in the continental US; of these, four are found in Maryland, and of those four, this is the only one you’re likely to see. The other three are critically imperiled here.

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R. caroliniensis ranges from New Jersey (where it’s endangered) west to Illinois, and then south to the Gulf coast.  It grows one to three feet tall.  I’ve seen references to it liking both dry, sandy soils and moist soils; the three places in the Gorge where I know to find it have sandy soils that are prone to minor flooding, so I’m not sure what to make of that.

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See the partly submerged rock on the lower right?  Yeah, that’s one of the places where this plant grows.