36 



a shrub zone which overhaings the shoreline. In addition, 

 Icirge deciduous tree species are aljxst always found along 

 the margins. 



2. Regicncil vegetaticn types; In Montana, within the Oedar- 

 Hemlock-Douglas-fir Forest Section; in eastern Washington 

 and Idaho, near the border between the Palouse Grassland 

 Province and the Douglas- fir Forest Section; and in western 

 Washington, within the Willainette-Puget Forest Province, all 

 as mapped by Bailey (1976) . In Montana, within the 

 Subalpine Fir, Douglas-fir, and Grand Fir Climax Forest zone 

 mapped by Ross and Hunter (1976) . The Idaho population 

 occurs in a ripariem zone at the interface of two Kuchler 

 types: Grand Fir-Douglas Fir Forests and Wheatgrass- 

 Bluegrass (Kuchler 1964) . Surrounding forest types fedl 

 into three Society of American Foresters (SAF) cover types: 

 Interior Douglas-fir (210) , Western Larch (212) , Grand Fir 

 (213) , and Western White Pine (215) (Eyre 1980) . Habitat 

 types fall into the grand fir, western redcedar, and 

 Douglas-fir series (Cooper et aj. 1987). 



3. Frequently associated species: In Montana, HcMellia 

 aquatilis is most often found in small pothole ponds of 

 glacial origin, at lower elevaticxTS in the Swan River 

 drainage. The zonal vegetation in these eureas consists of 

 diverse coniferous forests which contain varying amounts of 

 the following tree ^secies: 



Abies qrandis (Grand Fir) 

 Abies lasiocarpa (Subalpine Fir) 

 Larix occidental is (Western Larch) 

 Pioea enqelmannii (Engelmann Spruce) 

 Pinus oontorta (Lodg^xjle Pine) 

 Plnus monticola (Western White Pine) 

 Pinus ponderosa (Ponderosa Pine) 

 Pseudotsuqa menziesii (Douglas Fir) 



Iiiinediately surrounding the ponds in which H. aquatilis has 

 been found, the following deciduous broadleaf tree species 

 aa?e virtually edways present: Papulus tremuloides (Quaking 

 Aspen) and/or Populus trichocarpa (Black Cottonwood) . In 

 the northern Swan Valley, Betula papyri f era (Paper Birch) is 

 also associated with some sites. 



Shrub species bordering H. aquatilis sites include: 



Alnus incana (Thinleaf Alder) 

 Comus stolonifera (Red Osier Dogwood) 

 Juniperus communis (Coimon Juniper) 

 Rhamnus alnifolia (Alder Buckthorn) 

 Salix spp. (Willcws) 



Ihe following aquatic herbaceous species were found to be 

 connonly associated with H. aquatilis ; those marked with an 



