Puccinellia parishii

Known from scattered occurrences mostly in western New Mexico and northern Arizona, including many in Navajo Nation. Additional somewhat disjunct occurrences are found in Yavapai County, Arizona, southwest Colorado, San Bernardino County, California, and West Texas. Total number of occurrences is estimated to be approximately 28. Populations tend to be small in terms of both number of plants and area occupied. Occupies sites with a fairly specific hydrology (springs or seasonally wet areas that stay moist through the winter and spring). These sites also tend to be heavily used by humans and livestock. Major threats include alteration of habitat hydrology, conversion to agricultural or urban use, and overgrazing.

The range of Puccinellia parishii extends from San Bernardino County, California, to northern Arizona, and to New Mexico, with more recent discoveries extending it to southwest Colorado (in 1998) and to the Trans-Pecos region of West Texas (in 2013) (USFWS 1998; Flora of North America Editorial Committee 2007; Roth 2008; Heil et al. 2013; Carter et al. 2014). The species was considered falsely reported from Utah by Kartesz (1999) and is not in Welsh (2008). Utah County, in north-central Utah, is shown in Carter et al. (2014) but this is a false report, based upon a specimen which was later determined to be P. nuttallii.

Approximately 28 occurrences are known (Element occurrence data in the NatureServe central database as of August 2015; Carter et al. 2014). About 15 of these are in New Mexico (5 on Navajo Nation lands), about 9 are in Arizona (8 on Navajo Nation lands), 1 is in California, 2 are in Colorado, and 1 is in Texas.

Major threats include alteration of habitat hydrology (by capture/diversion for livestock and domestic use, groundwater pumping, flood control activities, erosion and stream entrenchment, salt cedar invasion, climate change, etc.), conversion of habitat to agricultural or urban use, and overgrazing. One or more New Mexico populations may be threatened by mining (Element occurrence data in the NatureServe central database as of August 2015). A Colorado occurrence is in a heavily-used area near a reservoir/pipeline and the primary threats are hydrologic alteration and recreation (Rondeau et al. 2011 cited by Colorado Natural Heritage Program 2013). The California occurrence is threatened by groundwater pumping, flood control, and trampling (CNPS 2015). At one Arizona site, Puccinellia parishii was observed growing in a heavily grazed wet meadow (Arizona Game and Fish Department 2015). It appears to be able to persist at springs that have been severely impacted by livestock grazing and trampling (McDonald 1999).