E. HABITAT 



1. ASSOCIATED VEGETATION: The Phillips County population on 

 BLM lands was associated with Eleocharis palustris and 

 Polygonum aviculare , both wetland species. The vegetation 

 of the Garfield County site was described as "rich". 



2. TOPOGRAPHY: Bacopa rotundif olia occurs on muddy shores and 

 shallow ponds or marshes. 



3. SOIL RELATIONSHIPS: It occupies saturated soils of clay or 

 silt particle size that are characterized as 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 grov/ing season due to evaporation or dropping 

 groundwater levels. 



F. POPULATION DEMOGRAPHY AND BIOLOGY 



1. PHENOLOGY: Flov/ering is indeterminate, beginning in June 

 and extending as late as August under suitable conditions. 



2. POPULATION SIZE AND CONDITION: It was noted as common in 

 the two recent sites where it was collected. The wetland 

 habitat areas in which these populations occur are small, so 

 that their numbers are likely to number no larger than 

 hundreds or some order of thousands in magnitude. 



3. REPRODUCTIVE BIOLOGY: It reproduces both sexually; and 

 asexually by rooting at the axils. 



G. POPULATION ECOLOGY 



1. BIOLOGICAL INTERACTIONS 



a. COMPETITION: The fact that the vegetation at one of its 

 Montana records was described as "rich" suggests that it can 

 compete with emergent vegetation. 



b. HERBIVORY: None known. 



H. LAND OWNERSHIP: The Garfield county site is on the C. M. Russell 

 National Wildlife Refuge, The Phillips County site is apparently 

 on private land, and the historic Cascade County site was likely 

 to have been on private land. 



