Sometimes, looking for plants and flowers in winter can be interesting, particularly near a source of fresh water in the desert. In November, I visited Rogers and Blue Point Springs on the north shore of Lake Mead in the Lake Mead National Recreation Area. Rogers Spring and other springs in the “North Shore Complex” comprise one of the terminal discharge areas for the regional carbonate-rock aquifer system of eastern Nevada and western Utah. The source of the water to this spring and other regional carbonate-rock aquifer springs is uncertain. The prevailing theory suggests that much of the recharge water that enters the carbonate-rock aquifer occurs in the high mountain ranges around Ely, Nevada, located 250 miles north of Lake Mead. As this ground water flows south through the carbonate rocks, it encounters several faults along the way, including the Rogers Spring Fault, which has caused the older carbonate rocks (primarily limestone and dolomite) to be displaced against younger evaporite deposits of the Muddy Creek and Horse Spring formations. Here, the lower permeability of these evaporite deposits, along with high subsurface water pressure, forces the ground water in the carbonate rocks to flow upward along the fault and emerge at the surface as Rogers Spring.
By definition, desert ecosystems receive little rainfall − less than 10 inches (25 centimeters) annually. For much of the year, the only locally and naturally available sources of surface water in the desert are seeps and springs − places where groundwater comes to the Earth’s surface. Wet islands of life surrounded by vast arid expanses, desert springs are globally recognized biodiversity hotspots that support both regionally important and locally endemic species. For example, the two areas of highest local endemism in North America include Cuatro Ciénegas Biosphere Reserve in the State of Coahuila, Mexico, and Ash Meadows National Wildlife Refuge in the Mojave Desert of Nevada. Both are desert spring complexes.
Blue Point Springs
Blue Point Spring is actually just a small meandering stream a mile or so down the road from Rogers Spring, with the spring head about a quarter of a mile off the road. In 1903 a project to build a canal to divert water from both springs to 500 acres of farmland located several miles south of St. Thomas was attempted but ultimately failed. Several other projects have been attempted in association with Rogers Spring and Blue Point Spring, including a water fowl refuge construction project that was initiated from 1938 through 1943 but never completed, and a tropical fish hatchery that operated at Blue Point Spring during the mid 1950s but also failed.
Desert or California Fan Palm
Contrary to popular belief, these trees in the palm family are not native to Lake Mead NRA. They were planted at Rogers and Blue Point springs to give the springs the feel of a desert oasis. Unfortunately, the trees harm the natural springs by using water and overwhelming native vegetation. The trees produce thousands of seeds that are carried by birds to other springs.
Thistle was growing everywhere around the spring. Cirsium mohavense is a species of thistle known by the common names virgin thistle and Mojave thistle. It is native to the southwestern United States, where it grows in moist areas in otherwise dry habitat, such as desert springs. It is most common in the Mojave Desert, found also in the southern Great Basin and other nearby regions of California, Nevada, western Arizona, and southwestern Utah. This thistle is a favorite of bumblebees but I only saw honeybees the day I visited.
Solitary Leaved Alkali Goldenbrush
Isocoma acradenia is a North American species of flowering plant in the daisy family known by the common name Alkali Goldenbush. The inflorescences along the top parts of the stem branches are clusters of four or five flower heads. Each head is a capsule encased in bumpy, glandular greenish phyllaries bearing many golden yellow disc florets at its mouth. Each disc floret is somewhat cylindrical and protruding and in Isocoma acradenia var. eremophila, the tips are rounded and touching, like two fingers. There are three subspecies but only two occur in Nevada, Isocoma acradenia var. acradenia and Isocoma acradenia var. eremophila. The primary difference seems to be the serrated leaves on I.s. eremophila. It flowers from August to November.
Solidago spectabilis is a species of goldenrod known by the common names Nevada goldenrod, basin goldenrod, and showy goldenrod. It is native to the western United States in the Great Basin and surrounding areas. It is found in California, Arizona, Nevada, Oregon, and Utah. It grows in moist habitat, including bogs, meadows, seeps, streambanks, hot springs, and wet areas on alkali flats. Each flower head contains 8–22 yellow disc florets surrounded 5–15 narrow yellow ray florets.
A dominant shrub of salt playas and mudflats in the American Southwest, the Iodine Bush is easily distinguished from great distances by the dark hue of its stems. The blackish-colored shrubs stand in stark contrast to surrounding vegetation and on close examination can be easily distinguished from the opposite-branched, but vegetatively similar members of Sarcocornia. The knobby green stems are fleshy and appear jointed at the internodes between segments. Often the segments are so short they are nearly round. The leaves appear as flaky scales scattered across the surface of the stems.
In North America, the status of Phragmites australis is a source of confusion and debate. It is commonly considered a non-native and often invasive species, introduced from Europe in the 1800s. However, there is evidence of the existence of Phragmites as a native plant in North America long before European colonization of the continent. The North American native subspecies, americanus (sometimes considered a separate species, Phragmites americanus), is markedly less vigorous than European forms. Until recently these two taxa were not distinguished, and efforts to eradicate the common reed may have impacted populations of the less common American reed. However, they are relatively easy to distinguish, and genetic studies confirm these morphological differences. The most apparent distinguishing field character is that the middle and upper stem internodes of American reed are smooth, shiny and red-brown to dark red-brown during the growing season. In common reed by contrast, the middle to upper stem internodes are dull, ridged, and tan-colored during the growing season.
Distichlis spicata is a species of grass known by several common names, including seashore saltgrass, inland saltgrass, and desert saltgrass. It thrives along coastlines and on salt flats and disturbed soils, as well as forest, woodland, montane, and desert scrub habitats. This grass is native to the Americas, where it is widespread. It can be found on other continents as well, where it is naturalized. It is extremely salt tolerant. Native Americans that inhabited California used saltgrass as a seasoning. They collected the salt crystals by threshing the blades. The seasoning provided is gray-green and said to have tasted like a salty dill pickle.
Tamarix chinensis is a species of tamarisk known by the common names five-stamen tamarisk and Chinese tamarisk or saltcedar. It is native to China and Korea, and it is known in many other parts of the world as an introduced species and sometimes an invasive noxious weed. Tamarix chinensis is associated with dramatic changes in geomorphology, groundwater availability, soil chemistry, fire frequency, plant community composition, and native wildlife diversity. It may also hybridize with Tamarix gallica or Tamarix ramosissima.
Arizona Grape Plant
Arizona grape is native to streambanks and moist shady river canyons of the southwestern United States and northern Mexico. Like other grapes, Arizona grape is a perennial vine with woody branches sprawls over rocks, shrubs, and trees. The Arizona grape is a vigorously branching vine. Stems are slender, with significant tapering from base to apex. Fully developed leaves resemble a three-lobed heart shape and generally grow to an average of 4 inches long/wide. Leaves exhibit irregular toothed edge. Green flower buds develop in clusters, and small flowers bloom in a whitish green hue. Globe or ovate shaped fruit are typically 1/3–3/8 in diameter; immature fruit is green in color, developing into a deep purple or black. The grapes of Vitis arizonica are not particularly tasty to humans and have a leathery skin that does not readily slip free of the juicy pulp, but are relished by birds.
Pluchea sericea, commonly called arrowweed or Cachanilla (Mexico), is a rhizomatous evergreen shrub of riparian areas in the lower Sonoran Desert and surrounding areas. It is common in the lower Colorado River valley of California, Nevada and Arizona, as far east as Texas, and in northern Mexico where it often forms dense impenetrable thickets. Flowerheads are produced in dense purple clusters at the top of the stems from March to June. It was once used medicinally by Native Americans as an antidiarrheal and eyewash. Other traditional uses include thatching, arrowmaking and food, especially the edible root.
Prosopis glandulosa shrubs and trees provide shelter and nest building material for wildlife, and produce seed pods in abundance containing beans that are a seasonal food for diverse birds and small mammal species. As the common name indicates, honey mesquite is a honey plant that supports native pollinator species of bees and other insects, and cultivated honey bees. Prosopis glandulosa has rounded big and floppy, drooping branches with feathery foliage and straight, paired spines on twigs. It can be part of the Mesquite Bosque plant association community in the Sonoran Desert ecoregion of California and Arizona (U.S.), and Sonora state (México). This was a good sized specimen, about 10 feet across and 5–6 feet tall.
Prosopis pubescens, commonly known as screwbean mesquite, is a species of flowering shrub or small tree in the pea family, Fabaceae, that is native to the southwestern United States. It is found along streams and valleys in deserts, particularly in damp or saline soil. It grows alongside common plants of this habitat type, such as arrowweed (Pluchea sericea) and tamarisks. It can be found on playas and other areas of alkaline substrates. This and other mesquite species are dominant plants in the Mesquite Bosque-mesquite woodlands, a common habitat type in the desert southwest region.
Rogers spring has been polluted with a tropical fish hatchery that operated at Blue Point Spring during the mid 1950s. Other than the fish, I saw the above House Finch with a number of other friends including a few Black-Tailed Gnatcatchers (Polioptila melanura). I also saw a Harris’s Antelope Squirrel (Ammospermophilus harrisii) although sadly missed the photograph. These islands of water function much like a riparian forest along a stream in the desert with surprisingly diverse flora and fauna.
As always, I hope you enjoyed the post and will return for more.