2. CURRENT SITES: All collections from the six Montana 

 counties mentioned above are recent; collected from eleven 

 locations . 



3. HISTORICAL SITES: None. 



4. UNVERIFIED/UNDOCUMENTED REPORTS: This species is locally 

 abundant around certain Badlands outwash channels of Harding 

 County, SD and is expected in adjoining southeastern Montana 

 in similar habitat. 



5. AREAS SURVEYED BUT SPECIES NOT LOCATED: The species was 

 sought upstream and downstream from newly-discovered 

 populations to delimit boundaries and characterize extent. 

 There are many streams and stream stretches that appear 

 similar to the locations where it was found but which do not 

 have the species. 



1. ASSOCIATED VEGETATION: The wet meadow and temporarily 

 inundated vegetation associated with graceful arrowgrass 

 typically includes saltgrass ( Distichilis stricta ) , Baltic 

 rush (Juncus balticus ) , foxtail barley (Hordeum jubatum ) ; 

 and may also include (Glaux maritima ) , ( Potentilla anserina ) 

 and ( Puccinnellia nuttalliana ) ; as well as both other 

 species of arrowgrass in the state ( Triglochin maritima , T. 

 palustre ) . At some sites, including the McCone County site 

 on State School land, it is locally dominant. 



2. TOPOGRAPHY: It occupies riparian habitat in the study area, 

 as well as wetland habitats elsewhere in Montana, at the 

 base of slopes. 



3. SOIL RELATIONSHIPS: It is found in highly alkaline settings 

 along ponds, springs, streams and outwashes. These soils 

 are saturated at least early in the growing season and have 

 a high clay content. They have a variety of sedimentary 

 parent materials. 



4. CLIMATE FACTORS: It occupies habitat having arid or 

 semiarid climates where salts accumulate at the surface. 



F. POPULATION DEMOGRAPHY AND BIOLOGY 



1. PHENOLOGY: The three study area populations documented were 

 found at different times in the 1993 growing season; a 

 season which generally was 2+ weeks late. Graceful 

 arrowgrass was in peak flowering on . . . The species is | 

 usually collected after it flowers in June. Its fruits " 

 persist in recognizable form until frost. 



