Propagation protocol for blowout penstemon (Penstemon haydenii), a federal endangered species of the Nebraska Sandhills and Wyoming

Abstract

Blowout penstemon (Penstemon haydenii S. Watson [Plantaginaceae]) is a federal endangered species endemic to the Nebraska Sandhills and the Ferris Dunes of south-central Wyoming. It is an early seral colonizer that recruits into active sand dune blowout areas. Seeds exhibit physical and physiological dormancy and require scarification and stratification for germination. At the USDA Forest Service Bessey Nursery, seeds are placed in a 20-min phosphoric acid bath, thoroughly rinsed in running water, and placed into a 30-d cold, moist stratification at 1 °C (34 °F). Germination rates of stored Nebraska seed sources average 30% or higher. Nebraska seedlings have been outplanted in suitable blowout areas on USDA Forest Service lands as one of the management objectives of the USDI Fish and Wildlife Service Endangered Species Recovery Plan. Outplanting survival rates vary from 5 to 50%, depending on post-establishment environmental conditions. Outplanted seedlings consistently produce seeds that contribute to the seedbank and seedling establishment.