67 



d . Vulnerability of pollinators: Unknown. 



3. Seed dispersal. 



a. General mechanisms: Although not 

 directly observed, the achenes are 

 presumably shaken from the heads and 

 fall a short distance from the parents. 

 Wind dispersal is unlikely, at least 

 over great distances, as the pappus in 

 Gr i nde 1 i a consists of firm awns which 

 are readily deciduous. 



The possibility of artificial dispersal 

 by human activities should not be 

 overlooked. The involucres in Gr i ndel i a 

 are extremely sticky-resinous, and 

 could easily adhere to passing vehicles 

 in cases where plants occur right along, 

 and in, the logging roads and trails 

 with which they are frequently 

 associated. Plants 2-3 feet tall were 

 often found in the center strip of 

 these roads, and they strike the front 

 and underneath sides of a passing 

 veh i c 1 e . 



b. Specific agents: None known. 



c. Vulnerability of dispersal agents and 

 mechanisms: Not applicable. 



d. Patterns of propagule dispersal: Not 



known in detail; many populations were 

 observed to contain a number of basal 

 rosettes. The populations generally 

 occur in well-defined areas, although 

 single, isolated individuals were found 

 on a few occasions within the region 

 covered by this study. 



U. Seed biology. 



a. Amount/variation of seed production: 



Details unknown; later surveys indicated 

 that seed set appears to be good. 



b. Seed viability and longevity: Unknown. 



c. Dormancy requirements: Unknown. 



d. Germination requirements: Unknown. 



e. Percent germination: Unknown. 



5. Seedling ecology: Details unknown; as noted 



