A Floristic inventory of the Ashland and Sioux Ranger Districts of Custer National Forest

Hans Hallman
Graduate Student, UW Botany Department

June 2009 saw the start of two field seasons of floristic inventory of the Sioux and Ashland Ranger Districts of Custer National Forest in southeastern Montana and northwestern South Dakota, as well as surrounding BLM lands. Having come straight from field work in southern Nevada where I was working in burned landscapes where trees are few and far between, the ponderosa pine (Pinus ponderosa) forests and relatively lush green ash (Fraxinus pennsylvanica) draws of Custer were quite a change in scenery. Overall, ca. 9,000 plant specimens were collected during the summers of 2009 and 2010, with a quick trip back in 2011 to pick up a couple of specimens of coralroot (Corallorhiza sp.) and orchard grass (Dactylis glomerata) in a more identifiable condition than when I first located them in 2010.

A green-ash draw along with grass- and badlands

Interesting habitat types completely exotic to me when I began the project were the numerous badlands that I was able to collect on. Hosting a sparse, yet distinctive, vegetative community, including species such as saltgrass (Distichlis spicata) and greasewood (Sarcobatus vermiculatus), the badlands and their exposed substrate horizons of dark brown to rose to white, and rain-sculpted rills and gullies sometimes 50 or more feet deep, often had me thinking I was on a different planet, especially after a long, tiring day of solo hiking and collecting. A highlight of collecting in one of these habitats was locating a new population of Visher’s buckwheat (Eriogonum visheri) in Montana, only the second population known from the state.

Thanks to tips throughout the collecting seasons from Sioux District Ranger Kurt Hansen, access to certain areas of the forest was streamlined, and several populations of regionally rare plants were located, including lesser yellow lady’s slipper (Cypripedium parviflorum var. parviflorum).

Identification of plant material is nearing completion, and I expect to soon start writing my thesis.