2 topography: It is at the bottom of the topographic 



aradient Two of the four known occurrences seem to be 

 Ie??inSs-whIch have been dug out, including the st°ckpond 

 setting of EG 001, and the storage pond setting of EO 004. 



3. SOIL relationships: The fine-particle, saturated soils on 

 which it grows are muck. 



4 CLIMATE FACTORS: Throughout most of its range, it is in a 

 ■ continental climate where evaporation and precipitation 

 levels are in dynamic equilibrium and the wetlands recede 

 during the growing season due to evaporation or dropping 

 groundwater levels. 



POPULATION DEMOGRAPHY AND BIOLOGY 



1 PHENOLOGY: Members of the genus flower from early summer 

 until fall, with flowering prolonged depending on water 

 levels They are difficult to locate until drawdown 

 condition after the submerging water has receded, and 

 require the mature seed for making identification. 

 Specimens of American waterwort have been collected m 

 Montana from 11 July through October. 



2. POPULATION SIZE AND CONDITION: Unknown. 



3, REPRODUCTIVE BIOLOGY: Unknown. 



G POPULATION ECOLOGY 



1. BIOLOGICAL INTERACTIONS 



a COMPETITION: This small short-lived plant might be expected 

 to be a poor competitor with other submerged vegetation, and 

 under eutrophic conditions that foster algal blooms. 



b. HERBIVORY: None known. 



c OTHER: This species has wide sporadic distribution, minute 

 seeds, and occupies mudflats; collectively indicating that 

 waterfowl may be an occasional dispersal vector. 



H. LAND OWNERSHIP: Three of the four knov/n occurrences are on 



federal lands, and the Ravalli County occurrence is on private 

 land (next page) . 



