Penstemon (deustus)

Ann DeBolt and Hilary Parkinson USDA FS - Rocky Mountain Research Station 316 E. Myrtle Boise, Idaho 83702 208-373-4366 208-373-4391 (fax) adebolt@fs.fed.us www.fs.fed.us/rm/boise

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Family Scientific Name:	Scrophulariaceae
Family Common Name:	Figwort family
Scientific Name:	Penstemon deustus Dougl.
Common Name:	Hot-rock penstemon, Scabland penstemon
Ecotype:	Foothills grasslands-shrublands (associated with mountain big sagebrush, bitterbrush, yarrow, ponderosa pine), Boise County, ID, 1176 m
General Distribution:	Widespread east of the Cascades, usually associated with basaltic rock, and occasionally limestone, in sagebrush, juniper, and pinyon-juniper communities from 800-2500 m. In eastern Washington, Idaho, southwest Montana, and south through Oregon to the central Sierra Nevada in California, the northern 2/3 of Nevada, northwest Utah, and western Wyoming.
Propagation Goal:	plants
Propagation Method:	seed
ProductType:	Container (plug)
Time To Grow:	0
Propagule Collection:	The white flowers bloom from May to July. Phenology varies based on elevation, aspect and seasonal weather patterns. The fruit (a capsule) is mature when it turns brown and begins to open. This typically occurs 5 to 8 weeks after flowering. Seed maturation is relatively uniform, and the brown to black seed persists in the capsules for several weeks. Seed capsules were collected by cutting mature inflorescences (racemes) with clippers and placing them into containers. The capsules were thoroughly dried and placed in a standard freezer for 48 hours to remove insect pests.
Propagule Processing:	Penstemon deustus seed is very small (2,000,000-2,900,000/lb) compared to other seed in this genus and requires additional time for cleaning. Large stems are first removed by coarse sieving, and capsules are crushed on a rubbing board. Material is then passed through 1.7 and 1.18 mm sieves with square openings (Nos. 12 and 16 USA STS), followed by cleaning with a seed blower. Remaining debris is then separated by passing it through a No. 18 USA STS four more times until clean.
Pre-Planting Treatments:	Seed was soaked in 250 ppm giberellic acid for approximately 24 hours and then placed in germination boxes on two layers of blotter paper moistened with distilled water. Additional water was added as needed. Seed was prechilled at 4§C in the dark for 60 days. Mold began to form inthe germination boxes after 30 days. The blotter paper was replaced and seeds were washed with Thiram, an anti-fungal seed protectant. After 60 days of prechilling, seeds were incubated in a germinator at a constant 21§C with exposure to 12 hours of cool-white fluorescent light alternating with 12 hours of darkness. Tetrazolium tests (Idaho State Seed Laboratory) determined that viability was 49% and purity 23% (11%). The use of 250 ppm giberellic acid and the 60 days cold moist treatment appears adequate in breaking seed dormancy for this accession. Germination of prechilled seeds began after 3 days of incubation and was 77% complete by the 4th day. Total germination percentage was 97%.
Growing Area Preparation/ Annual Practices for Perennial Crops:	Upon first signs of germination, seeds were sown (and barely covered with soil)in styrofoam conetainers filled with a 50% peat and 50% vermiculite mixture. Soil was watered from an overhead irrigation system that turns on automatically when soil saturation levels fall below 80%, and off at 100% field capacity. Greenhouse temperature is set at a constant 27§C. Small amounts of fertilizer suitable for seedlings were added periodically.
Establishment Phase:	Only 9% of the germinants developed into healthy seedlings in the greenhouse.
Other Comments:	Partial funding for this research was provided by the USDI Bureau of Land Management, Great Basin Restoration Initiative. The use of trade or firm names in this publication is for reader information and does not imply endorsement by the U.S. Department of Agriculture of any product or service. This publication reports research involving pesticides. It does not contain recommendations for their use, nor does it imply the uses discussed here have been registered. All uses of pesticides must be registered by appropriate State and/or Federal agencies before they can be recommended. CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and fish or other wildlife-if they are not handled or applied properly. Use all pesticides selectively and carefully. Follow recommended practices for the disposal of surplus pesticides and pesticide containers.
References:	Hitchcock, C. Leo and Arthur Cronquist. 1973. Flora of the Pacific Northwest. University of Washington Press, Seattle, WA. 730 p. USDA, NRCS. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Citation:

Parkinson, Hilary; DeBolt, Ann. 2005. Propagation protocol for production of Container (plug) Penstemon deustus Dougl. plants USDA FS - Rocky Mountain Research Station Boise, Idaho. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2024/07/02). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.