Germination studies conducted at the Berry Botanic Garden were highly variable. In several trials, seeds were subjected to either eight weeks of cold stratification or no cold stratification and then subjected to either constant 68F (20C) or alternating 50/68F (10/20C) temperatures. Depending on the treatment, between 0-60% of the seeds germinated. However, results were inconsistent between trials, perhaps due to differences in seed viability (BBG Files).

Genetic studies utilizing isosymes (enzyme analysis) to determine the genetic diversity within and between populations of P. barrettiae. Penstemon barrettiae was found to have high genetic variation with levels of variation greater than that for most restricted endemic plant species. Morphological comparisons between populations were conducted by taking data on leaf length, width, and serrations; inflorescence number and length; and plant diameter and height. All sampled traits differed significantly among populations. This may be due to moisture gradients and substrate differences (Burkhart 1996).

A Washington and Oregon endemic. Known from a narrow strip - about 8 km long - on both sides of the Columbia River Gorge and in the canyon of the Klickitat River, a Columbia tributary. An additional population, 72 km to the west, was discovered in 1985, just before its habitat was destroyed during construction of a navigation lock. Cuttings from this population were salvaged and transplanted to two nearby sites. Threats to existing populations of Penstemon barrettiae include herbicides used to clear nearby highway and railroad embankments, rock garden plant collectors, road construction, quarrying, timber harvest, and changes in hydrology that may reduce the availability of water. There are nine sites that are historic or possibly extirpated that should be surveyed to confirm the presence/absence of the species.

Horticultural exploitation (Meinke 1982). Road construction, construction activities (Meinke 1982). Herbicide spraying along railroads and highways (Grettenberger 1987). Localized distribution (Grettenberger 1987). Habitat loss due to quarrying o

8 sites are known in Oregon with unknown numbers of individuals. Most occur near Hood River, but one population was found approximately 45 miles to the west (a surprising range extension) at Bonneville Dam. (Wasco Co., Hood River Co., 1 in Multnomah Co.) (Oregon Natural Heritage Database). In Washington, there are about 17 presumed extant occurrences (16 in Klickitat Co, 1 in Skamania Co.). Not all populations have been surveyed. As of 1995 (of those with known pop size estimates) 2 populations had fewer than 10 individuals, 3 had between 10 and 20, 3 had between 100 and 200, 3 had between 200 and 450, 1 had approximately 650 and 1 had approximately 2,700 (WNHP 2000).

Genetic studies utilizing isosymes (enzyme analysis) to determine the genetic diversity within and between populations of P. barrettiae. Penstemon barrettiae was found to have high genetic variation with levels of variation greater than that for most restricted endemic plant species. Morphological comparisons between populations were conducted by taking data on leaf length, width, and serrations; inflorescence number and length; and plant diameter and height. All sampled traits differed significantly among populations. This may be due to moisture gradients and substrate differences (Burkhart 1996). Germination studies conducted at the Berry Botanic Garden were highly variable. In several trials, seeds were subjected to either eight weeks of cold stratification or no cold stratification and then subjected to either constant 68F (20C) or alternating 50/68F (10/20C) temperatures. Depending on the treatment, between 0-60% of the seeds germinated. However, results were inconsistent between trials, perhaps due to differences in seed viability (BBG Files).

Cuttings and seeds were taken from plants that were to be destroyed by blasting for construction of a lock at Bonneville Dam. Since P. barrettiae is not a listed species, the Army Corps of Engineers was under no obligation to protect the plants. Despite this, the Corps was enthusiastic about saving the plants. Seeds and cuttings were collected rather dramatically from the high cliffs using an aerial lift. Rooted cuttings were placed in permanent beds at Bonneville Dam and after construction, plants were re-planted on the newly exposed rock cliffs (Kierstead 1986). Seeds from two sites in Oregon and two sites in Washington are stored at The Berry Botanic Garden.

Additional surveys to search for additional populations and to assess the range of known populations (WNHP 1999).

Collect and store seed from across the species range. Determine optimum germination conditions. Study innate seed viability and long-term viability after prolonged storage. Determine propagation and reintroduction protocols.