21 



occurs now and then but does not reproduce." 

 As Watson (1976) noted, this hybrid origin 

 has never been experimentally confirmed by 

 crossing the two putative parents. However, 

 field observations and the collection of 

 additional specimens and mature 

 inflorescences during this study provided 

 further material with which this theory can 

 now be more strongly supported. The evidence 

 on which this theory is further based here 

 includes a.) a more detailed morphological 

 comparison of certain characters from the 

 three taxa (Table E, p. S2), and b.) the 

 results of seed viability tests (Table 1, p. 

 19). Samples from 1_. canescens and T. wo 1 f i i 

 showed good seed viability (76-80*/.) for these 

 two species; in contrast, samples from T. 

 or thochaetum revealed very little or no 

 production of viable seed (0-3*/.). Three 

 inflorescences from one cluster (NE'-JSE'-^ 

 Section 15) had a few viable seeds (S-3'/.), 

 suggesting that the putative parents are 

 slightly more genetically interfertile at 

 that location. The results of these 

 comparisons and tests add further evidence 

 that T. or thochaetum is an interspecific, 

 virtually sterile hybrid between !_. canescens 

 and T. wo 1 f i i . 



S. Artificially induced: None known; both 

 Watson (1976) and Harvey (Appendix A) 

 collected the putative parents, but 

 apparently neither was able to produce an Fl 

 hybr id . 



3. Potential in cultivation: Unknown, probably 

 good. 



E. Other factors of population ecology: None known. 



Current land ownership and management responsibility. 



A. General nature of ownership: Private (Granite 

 Creek South and North sites), and United States 

 Government (Granite Creek Central site). 



B. Specific landowners: 



1. Champion International Corporation 



a. Granite Creek South (portion). 



b. Granite Creek North (all). 



2. Burlington Northern Railroad 



a. Granite Creek South (portion). 



