Tag Archives: Asteraceae

Does Dune Horsebrush Occur in the Bodie Hills?

Tetradymia tetrameres isn’t normally a hill-dwelling plant. As the common name suggests, it’s found most often in deep sands and old, stabilized sand dunes (foreground and center, in the photo above). Deep sand and old dunes usually occur in valleys and basins, not hills, though sometimes deep sandy soils can be found in canyons or ravines that penetrate hilly uplands.

Dune horsebrush near the mouth of a canyon entering Adobe Valley.

In California this plant found in the north and northeastern Mono Basin, in Adobe Valley (southeast of Mono Basin), and perhaps in Deep Springs Valley (south of the White Mountains). The CNPS Inventory of Rare and Endangered Plants ranks it as “fairly endangered in California, common elsewhere” but globally it’s “apparently secure, considering populations outside California”.

Outside of California, the “global” range of dune horsebrush encompasses just a handfull of counties in northwest and central Nevada — again, mostly in “sand dunes,” “sandy desert,” “dunes of compacted sand,” “sand in and around small, rather stable dunes,” etc.

Persistent phyllaries and lingering papus bristles give dune horsebrush
a bright appearance during September and October.

But does it occur in the Bodie Hills? Well, there’s an unnumbered collection by the Mariposa-based lawyer/botanist Joseph Whipple Congdon dated Aug 17, 1898. The location is given as “Bodie. Desert road.” Berkeley Mapper places the collection site near Bodie, which is logical based on the label information, but unlikely because there are no deep sands or dunes near Bodie. Having not seen this ancient specimen (DS1815), I thought it might be misidentified, but the specimen bears no annotation labels changing the determination, and Congdon had previously collected Tetradymia canescens, again without subsequent corrections.

His other collection locations on August 17  (“Mono Lake,” and “Desert Road”) shed no further light on the location of the Tetradymia. But on the 13th he was at Mono Pass and Bloody Canyon. On the 14th he was at Walker Lake. On the 15th and 16th he was at “Walker Lake to Mono Lake,” “Below Walker Lake,” and “Near Mono Lake.” So this was the smaller Walker Lake east of Mono Pass, not the larger Walker Lake near Hawthorne in Nevada. I think he may have spent a night or two at Goat Ranch on the south edge of the Bodie Hills, because he collected there on the 18th, then on the 19th he was on his way to Bridgeport. I doubt he even went to Bodie on this trip.

So where did Congdon collect his Tetradymia tetrameres, and was it “in the Bodie Hills”? I think he encountered it in the stabilized dunes he would have passed through if he had traveled the road from the DeChambeau Creek area, past DeChambeau Ranch (on today’s Cemetery Road) to Goat Ranch. Today, these dunes are also crossed by Highway 167, and the practiced eye will easily recognize dune horsebrush there on both sides of the highway north of Black Point. But this is clearly in the Mono Basin, not in the Bodie Hills, and some 9 to 11 air miles from the town of Bodie.

Part of the 1911 USGS 1:125,000 Bridgeport quadrangle, showing
the many roads between Black Point and Goat Ranch.

Dune horsebrush along Highway 167, north of Black Point.

There are, however, at least a few individuals of T. tetrameres actually in the Bodie Hills, just barely, along Cottonwood Canyon Road, near the mouth of Cottonwood Canyon, in sandy soil, but uncharacteristically in pinyon pine woodland. Having also seen dune horsebrush on sandy flats and slopes in a canyon of the southern Adobe Hills, at the northwest end of Adobe Valley, I would not be surprised to see more of it along the southeast edge of the Bodie Hills, where sandy deposits of the northeastern Mono Basin climb into some of the little valleys and canyons west and northeast of Cedar Hill.

Dune horsebrush in marginal habitat at the edge of the Bodie Hills.

Dune horsebrush has a very limited range in California. It has a wider range in Nevada, but is still endemic to the western and central Great Basin. It is easily overlooked and partial to remote, dry, dusty places, so I think a lot more of it could be found with some deliberate searching.

•     •     •

Speaking of “horsebrushes,” what other Tetradymia species occur in the Bodie Hills? Tetradymia canescens, “gray horsebrush,” is common (but rarely if ever abundant) on dry slopes among sagebrush through much of the range. Tetradymia glabrata, “little leaf horsebrush,” was collected somewhere on Rough Creek by Clare Hardham in 1969, and near lower Cottonwood Canyon by Frank Vasek in 1975. I’ve seen it on a low ridge at the west end of Fletcher Valley. Tetradymia spinosa, the (visiously) “spiny horsebrush,” is found in the northern and eastern foothills of the Bodie Hills.

Tetradymia canescens

Tetradymia spinosa

 


Copyright © Tim Messick 2017. All rights reserved.
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Food of the Gods in the Bodie Hills

How can a scrawny plant, growing in disturbed soils, with painfully sharp spines all over its fruits come to be named  for the mythical “food of the Greek gods”—Ambrosia—a name also related, apparently, to the Greek word for immortality, αθανασία (athanasia)? Carl Linnaeus himself, the “father of modern taxonomy,” bestowed the name in 1754. But why Ambrosia? I haven’t found an explanation. The authoritative Flora North America says “allusion unclear.” One might say it’s a crusty old botanist’s joke on posterity, but I won’t impugn the intentions of the great Linnaeus. The genus isn’t native to Sweden and he may have examined only a few specimens from North America (collected by others). Maybe they smelled nice, but he probably didn’t get to know the genus well enough.

Ambrosia

Ambrosia acanthicarpa, annual bur-weed or annual ragweed, grows on disturbed, sandy soils, often along roadsides, throughout much of western—especially southwestern—North America. The plants seen here were on a dirt road near the north edge of the Bodie Hills, in Lyon County, Nevada. I’ve also seen it beside Hwy 270 at Mormon Meadow and I’ve probably overlooked it at other locations. (Though you’re not likely to overlook it if you encounter it while wearing open-toed sandals.)

It’s not immediately obvious, but Ambrosia is a composite—in the sunflower family (Asteraceae). There are more than 40 species of Ambrosia in the New World, mostly in western North America. Ambrosia now includes plants formerly placed in Hymenoclea and Franseria.

Ambrosia

Despite its vicious demeanor, Ambrosia has an intriguing anatomy. The male flowers, bulging with stamens, are tightly clustered into numerous small heads, dangling along the axis of a tall raceme. The pollen shed from those anthers causes agonizing irritation of eyes and sinuses in anyone getting a face-full of the stuff. Magnified, the pollen grains look like lethal medieval weapons.

ambrosia_artem-wikipedia

While the male flowers will insult your eyes and upper respiratory system, it is the female flowers that will draw blood from your toes and fingers. Pistillate flowers are in the axils of leaves below the staminate inflorescence—the better to catch those heavily armed pollen grains. They lack corollas and are encased, usually one at a time, in a long-spined “bur.” (These spines are derived from the paleas—in Asteraceae, the usually very thin, papery, scale-like or bristle-like “chaffy bracts” at the base of each flower.)  As the fruit matures, the bur becomes very hard. The spines stiffen and become very sharp.

Ambrosia

Did you notice the tire tracks in the first photo? Above you see evidence for one of this plant’s long-range dispersal mechanisms. The mature burs attach themselves freely to automobile tires. No doubt this is one reason Ambrosia acanthicarpa is fairly common along disturbed road shoulders and many lesser-used unpaved tracks throughout the American west.


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