In the News

Conserving Tahoe’s Most Imperiled Plant: Tahoe Yellow Cress
date posted: November 12 2003

y John Cobourn, Water Resource Specialist;
Heather Segale, Environmental Education Coordinator; University of Nevada Cooperative Extension

Only a few areas as small as Lake Tahoe can claim to be the only home to a species. Tahoe Yellow Cress (Rorippa subumbellata) is a small, low-growing plant found along the shores of Lake Tahoe and nowhere else in the world. Tahoe Yellow Cress has tiny ¼-inch, yellow, round or cup-shaped flowers, with four petals and somewhat fleshy stems and leaves. Whole plants are often only an inch or two wide, but some may grow to a foot or more.

Tahoe Yellow Cress is a perennial, the rootstock surviving from year to year, with the stems lasting just one growing season. Tahoe Yellow Cress generally begins to grow in April and will flower from late spring through early fall. Based on recent shorewide surveys, Tahoe Yellow Cress occupies less than 30 percent of its known historic sites around the lake. Evidence suggests the current decline is due to a variety of causes, including increased human use of the lakeshore habitat.

Despite the fact that regulatory and land management agencies within the basin have established protective measures for Tahoe Yellow Cress, the number of plant populations has dropped from 34 locations in 1993 to just 14 in 2000. We are struggling with balancing the recreational demands on Lake Tahoe’s publicly owned shoreline with the need to sustain this plant. In addition, given that Tahoe Yellow Cress can also grow on private shoreline property, private landowners have a critical role to play in the survival of the species.

Tahoe Yellow Cress typically grows on open, sandy beaches or dunes, especially near the edge of the lake, stream mouths and back lagoons. It can often be found in the company of other plants, including rushes, sedges, willows and various grasses.

Tahoe Yellow Cress usually occupies only a small portion of any one beach, and simply knowing how to identify it is the first step to protection. Protecting Tahoe Yellow Cress can be as easy as giving it a little room on your beach. We can also let our visitors and others know about the plant, and how to avoid trampling it.

Why we should care so much about Tahoe Yellow Cress? According to Mike Vollmer, Tahoe Regional Planning Agency (TRPA), “Extinction is forever, so we feel some obligation to at least provide a place for it to perpetuate. There is also a genetic legacy that we are not aware of. We don’t know what role Tahoe Yellow Cress plays in the ecology here. We don’t know what else is connected.” Here are some ways that we can help protect Tahoe’s own Yellow Cress.

• Learn to identify the plant.
  
• Survey your property for Tahoe Yellow Cress. Pay close attention to sandy beach areas close to water sources.
  
• Keep out of fenced and signed areas that indicate sensitive habitat.
  
• Become an active Tahoe Yellow Cress steward; for more information, contact TRPA, (775) 588-4547, Ext. 229.
  
• Redirect sunbathing, picnicking and beach games away from Tahoe Yellow Cress, whether on public beaches or private property.
  
• Launch and store watercraft away from the plant.
  
• Eliminate or reduce beach disturbance such as beach raking. Whenever possible, remove beach litter by hand. Use soft leaf rakes if raking is necessary.
  

Photo Caption: “A typical Tahoe Yellow Cress plant grows here on sand among natural needle and bark litter.”

Watch for “The Lake Tahoe Report” each week on KOLO-TV News Channel 8 Tuesdays at 5 p.m. to learn more. Next week, learn about snow removal practices that can help protect the water quality at Lake Tahoe. “The Lake Tahoe Report” is a collaborative effort of the Lake Tahoe Environmental Education Coalition, University of Nevada Cooperative Extension, UC Davis and the USDA Forest Service. For more information, contact Heather Segale, University of Nevada Cooperative Extension, (775) 832-4138, or logon to www.lteec.org or www.unce.unr.edu.