I’ve posted previously on visiting the low sand dunes at Tonopah Junction in Mineral County, near Rhodes Marsh. Sarcobatus vermiculatus (Greasewood) and Suaeda nigra (Bush seepweed) dominate the vegetation here, largely stabilizing the dunes. I visited again this month (May 2022) and was greeted with a spectacular display of Carsonia sparsifolia (Fewleaf spiderflower or Naked spiderflower). Carsonia is a monotypic genus (just one species) in the Spiderflower family, Cleomaceae, although Carsonia was originally placed in the closely related genus Cleome.
Carsonia flowers have 4 green sepals, 4 yellow recurved petals, and 6 exserted stamens. Fruits are slender and generally borne on an elongated gynophore (a basal stalk that extends the ovary and fruit beyond the receptacle where sepals and petals are attached). Leaves are usually palmately compound, often trifoliolate (with 3 leaflets), with a short, orange-yellowish petiole-like stalk (a petiolule) at the base of each leaflet. The uppermost leaves are often simple, looking like a single leaflet.
Within its range, Carsonia most resembles several species of Cleomella and Peritoma that have similar yellow flowers and trifoliolate leaves. Cleomella fruits are short (up to 6 mm long) and may be nearly as wide; Carsonia fruits are longer (15–45 mm) and thin (1–3 mm). Peritoma has a dense, many-flowered inflorescence; Carsonia has a very open, relatively few-flowered inflorescence.
As you can tell from these photos, Carsonia inhabits sand dunes, as well as sandy areas on alkaline lake margins. Carsoniahas been collected throughout the western Great Basin, from Owens Lake and Ash Meadows north to the Black Rock Desert and Winnemucca, and from Carson Valley east to Railroad Valley and Sand Spring Valley. This population at Tonopah Junction has been previously documented in herbarium collections, but not on iNaturalist.
Does Carsonia occur in the Bodie Hills? Probably not, but it has been seen around the northeast side of Mono Lake.
Also flowering here this time of year: Oenothera deltoides ssp. piperi (Birdcage Evening Primrose).
Tonopah Junction simmers in the summer heat of the vast and nearly uninhabited Soda Spring Valley in Mineral County, Nevada. In the southern, lowest part of the valley lies the crusty and mostly glaring-white bed of Rhodes Marsh, which is itself a remnant of Pleistocene Lake Rhodes. US Highway 95 skirts the lake bed, a little north of half-way from Hawthorne to Tonopah.
So, why botanize here? Twice this year I’ve stopped near the intersection of US-95 and NV-360, curious to look at the sand dunes southwest of Rhodes Marsh to see if Dune horsebrush (Tetradymia tetrameres) or other interesting dune endemics might be found here. Neither early April nor late August were botanically optimal times to visit. June might be the time to find the greatest number of plants in bloom.
This is not a tall, impressive dune system, though it covers about 1.5 square miles. The dunes are all low and stabilized by vegetation. In spite of (or maybe because of) these characteristics, such dunes can provide habitat for some interesting plants (and invertebrates). The dunes near Tonopah Junction are all anchored beneath greasewood (Sarcobatus vermiculatus); many also have Bush seepweed (Suaeda nigra) on their sides or in swales between the dunes. I believe I saw one Naked spiderflower (Carsonia sparsifolia) seedling in April, but it was far from flowering yet. I would expect to find Nevada wormwood (Euphrosyne nevadensis) here during the summer. In late August, an acre or more of the distinctive skeleton-like remains of Dune evening primrose (Oenothera deltoides) was seen. I’ve yet to find Dune horsebrush there, but remain hopeful.
Nothing is left of the historic Carson and Colorado Railway and station at Tonopah Junction apart from an eroded roadbed and some debris. The only attraction left here is the ruin of an old stone house, now sadly filled with trash and defaced by graffiti. This was apparently part of Sully’s Tourist Camp, started by C.E. “Sully” Sullivan of Hawthorne in 1937. It looks as though the project was never completed—which is sad, because I think this would be a delightful place to rent a rustic cabin, tepee, or yurt for a few days. There’s hardly any information about Sully’s on the internet, but Tami, at the the Gouge Eye Chronicle blog, has unearthed a few details.
Anyone looking to make useful contributions to the documentation of biodiversity in the Great Basin on iNaturalist might consider an expedition to Rhodes Marsh, Teels Marsh (in the next valley to the west), and the surrounding hills. Very few observations or collections have been made in this area.
All photos, maps, and text are copyright Tim Messick 2015-2022, except where other sources are given credit. All rights reserved. No copying or modification without written permission. Links are welcome. Thanks!