56 



This phenomenon is best exemplified at the 

 Mollet Park site (020). Mollet Park is a 

 large, undisturbed Pestuca scabrel 1 a 

 grassland in good condition. The northern 

 portion of this area has been planted to a 

 Pi nus ponderosa plantation. Furrows one to 

 two feet deep were dug, and the trees planted 

 in the bottoms. Gr i nde 1 i a howe 1 1 i i has 

 agressively invaded a portion of the 

 plantation, spreading along the furrow 

 bottoms. The species was not found at all, 

 however, in the undisturbed portion of the 

 grass 1 and . 



Further evidence that Gr i ndel i a howel 1 i i 

 behaves as a ruderal species is provided by 

 the fact that, of the ^5 populations studied 

 in Montana, ^+2 (937.) of these occur in 

 lightly to heavily disturbed habitats. Of 

 these latter sites, 2<+ (53V.) occur only 

 along roadsides, and are often most likely 

 the results of introduction. Surveys away 

 from the roads at many of these sites did 

 not reveal any plants in less disturbed 

 hab i tats . 



6> . Dependence on dynamic aspects of biotic 



associations and ecosystem features: 



Details unknown; it is probable that certain 

 events, such as forest fires or tree falls, 

 could lead to an increase in abundance if a 

 seed source was nearby. 



7. Other endangered, threatened, rare, or 



vulnerable species occurring in habitat of 

 this taxon: None known or observed. 



7. Population biology of taxon. 



A. General summary: Populations generally consist 

 of approximately 10-300 flowering individuals. 

 Sterile basal rosettes Are evident at virtually 

 every site, suggesting good seedling establishment 

 and survivorship. The species is capable of 

 invading disturbed areas, and appears to prefer 

 early successional stages. Pollination by 

 members of the genus Bombus was observed; the 

 breeding system probably combines outcrossing and 

 se 1 f i ng , as bumblebees were observed to visit 

 flowers on the same plant and on separate plants 

 while foraging, 



B. Demography. 



1. Known populations: Forty-five extant 



