|White Bluffs bladderpod|
|Rollins, R.C., K.A. Beck, F.E. Caplow|
|Edward Guerrant, Ph.D.|
The following Participating Institutions are custodians for this species in the CPC National Collection:
Rae Selling Berry Seed Bank & Plant Conservation Programs
University Of Washington Botanic Gardens
The conservation of Physaria tuplashensis is fully sponsored.
Edward Guerrant, Ph.D. contributed to this Plant Profile.
In 1994, the Nature Conservancy of Washington and the US Department of Energy began the Hanford Biodiversity Project. The Hanford Nuclear Site, through which the Columbia River flows in south-central Washington, contains some of the largest remnant areas of ungrazed and undeveloped shrub steppe in the Pacific Northwest. The land had remained undisturbed as a security buffer zone around the nuclear reactor for at least 50 years. Intensive surveying and mapping was conducted to determine the plants and animals present on the site. Among the 30 different rare plant taxa found on the site, three were new to science, including Lesquerella tuplashensis, or White Bluffs bladderpod.
Was this new species a product of nuclear radiation A tongue-in-cheek article, suggesting that the new species found at Hanford were mutants, appeared in Outside Magazine shortly after the findings were announced. However, in this instance, we know that this species is not the result of a radiation-caused mutation. This plant was originally collected in the 1880's by one of the first natural history explorations in the Pacific Northwest. Botanists noticed that they were different from any known plants, but the specimens were not in good enough condition to lead to the conclusion that they were a different species. As a result of the work by the Hanford Biodiversity Project, the mystery was finally solved.
Lesquerella tuplashensis occupies a narrow ribbon of habitat that is only 5-40 ft (1.5-12 m) wide, and about 10 mi (17km) long, at the top edge of the dramatic White Bluffs above the Columbia River. Few other plants grow on the steep, almost vertical, habitat. The soil that it grows on is dry and highly alkaline (high pH) due to the high calcium content. The calcium in the soil causes the soil to be white. The name "tuplashensis" is derived from the Sahaptin language of the Wanapum tribe that occupied the White Bluffs area. "Plash" referred to the white color of the bluffs, and "Tuplash" was their name for the Bluffs (Rollins et al. 1995).
Distribution & Occurrence
Found growing on dry, barren, nearly vertical exposures of Calcium carbonate soil (high pH). The elevation ranges from 780 to 890 ft (150-290 m). The associated species include Astragalus caricinus, Astragalus geyeri, Cuscuta denticulata, Cammissonia pygmaea, Cryptantha spiculifera, Eriogonum microthecum, and Poa sandbergii.
|1 population (Washington Natural Heritage Program, 1999). Approximately 50,000 individuals (Florence Caplow, pers. comm.). About 5 % of the population is on private land (WNHP 2000).|
Conservation, Ecology & Research
The 10 mile (17 km) long population is divided into two portions that vary greatly. The northern portion is in a more pristine state. There are no agricultural disturbances. It consists of a fairly continuous band of 6 miles (10 km) at the top of the bluff between 885 and 950 ft (270-290m) elevation. The southern portion of the population consists of several discontinuous patches separated by a series of several large gaps created by ancient natural landslides, dissected topography, and recent slumping due to irrigation. Agricultural activities and irrigation are common above the top of the bluff. Aggressive non-native weeds, such as yellow star thistle, invade the area. The plants in the south grow at elevations of 490 to 900 ft (150-275m) (Dunnwiddie et al.).
The plant is a short-lived perennial. It has an average life span of three to five years. Within limited areas, numbers fluctuate greatly from year to year (Florence Caplow, pers. comm.). A significant decrease in the number of individuals should only be seen as a problem if it persists over several years (Dunwiddie et al.).
The plant often blooms twice each year. It first blooms in May and June, and then if conditions are right, it blooms again in July and August. This is quite surprising, for the area that it inhabits is extremely hot and dry in the summer. All other plants in the area are dormant at this time, but Lesquerella tuplashensis blooms into a golden carpet (Florence Caplow, pers. comm.). The Lesquerella tuplashensis plants in the southern part of the range bloom up to two weeks earlier than those in the north (Dunwiddie et al.). The closely related plant, L. douglasii, has never been seen in bloom in late summer (Florence Caplow, pers. comm.).
Slope failure due to subsurface runoff of irrigation water (WNHP 1999).
Ongoing monitoring and life history research (demographic studies), 1997-present (Dunwiddie et al.).
Taxonomy investigations. Researchers are comparing Lesquerella tuplashensis and L. douglasii on the basis of morphometric characteristics, ribosomal DNA, and in common garden experiments (Florence Caplow, pers. comm.). One PhD thesis (Simmons 1999) suggested that L. tuplashensis may be an ecotype of L. douglasii. Other observers and scientists disagree with this conclusion and are attempting to resolve the issue (see the ecology section).
Marking and hand spraying of invading yellow star thistle (Centaurea solstitialis) (Florence Caplow, pers. comm.).
Seeds from the only known site are housed at The Berry Botanic Garden. The single collection represents a bulk collection; there is no separation of maternal lines.
Significant portion of the area is fenced and Off-Road Vehicle (ORV) use is prohibited (WNHP 2000).
Much of the site is open to recreation and hunting (WNHP 2000).
Study pollination biology (pollinators, etc) (Dunwiddie et al.).
Determine production, viability and longevity of seed as well as if a soil seed bank persists (Dunwiddie et al.).
Additional monitoring to determine the magnitude and frequency of changes in population numbers and to determine the causes of the annual fluctuations (Dunwiddie et al.).
Determine germination requirements.
Determine reliable propagation protocols and reintroduction methods.
Hall, J.A. 1998. Biodiversity inventory and analysis of the Hanford Site: 1997 Annual Report. Seattle, Washington: The Nature Conservancy of Washington.