E. simplex (20 specimens). See Table 2 for itemization of characters. Specimens were collected 



July 17 to August 5, 1992, from the Bob Marshall Wilderness, Lewis and Clark National Forest, 



northwestern Montana, and the Bridger Range, Gallatin National Forest, in southwestern Montana. 



^ Phenetic analysis, including calculation of a phenetic distance matrix, cluster analysis, and 



f ordination, was performed using the computer program NTSYS (Applied Biostatistics, Inc.). 



Chromosome counts for E. lackscbewitzii were attempted using standard anther squash and 

 staining techniques. Seed germination was attempted according to procedures oudined by 

 Spongberg (1972) on four dried mature heads by placing disk and ligule achenes on moist filter 

 paper in a cool refrigerator at 25°C for one week to simulate stratification prior to germination. 



Specimens of E. simplex, E. ochroleucus, E. radicatvs, and E. lackscbewitzii were sent to Western 

 State College, Gunnison, Colorado, for scanning electron microscopic analysis of pollen grains 

 upon request from Wayne Wamken as a student project. 



RESULTS 



DNA restriction site variation 



Of the twelve restriction endonucleases, informative fragment length variations were found with 

 four (Table 3), while the remaining eight are still under study. Chloroplast DNA probe regions S6 

 and P3 displayed greatest variation with five mutations each; probe regions S8 and P8 each had 

 two mutations, while no significant variation was found in probe region P6. Unique cpDNA 

 fragment si2es were found for five of the six species. 



Regarding nuclear rDNA repeat regions, BcII revealed a site responsible for a possible 7.8kb 

 doublet specific to £. radicatus, one E. simplex (ESI 3), E. speciosus and E. caespitosus, and 

 another site responsible for 3.4kb + 7.2kb fragments potentially unique to the second E. simplex 

 (ES21). Other nuclear rDNA variation exists and is in the process of being analyzed. 



A dendrogram based on the presence of shared restriction sites revealed greater distances between 

 the ingroup and outgroup than within each group (Figure 2). Specifically, E. lackscbewitzii is 

 most similar genetically to E. radicatus and £. ochroleucus, based on this sample. These distances 

 will be converted to genetic distances in the final report. 



Morphological stvdics 



Ordination of the phenetic data set revealed a distinct clustering of individuals belonging to E. 

 simplex and an indistinct clustering of individuals belonging to E. ochroleucus, E. lackscbewitzii, 

 and E. radicatus (Figures 3 and 4). Figure 5 illustrates the cluster analysis of phenetic distances 

 calculated between all pairwise comparisons of individuals of E. simplex, E. radicatvs, E. 

 ochroleucus and E. lackscbewitzii. Erigeron lackscbewitzii specimen EL203 was the only 

 individual to be placed a relatively great phenetic distance from the other E. lackscbewitzii 

 specimens due to its unusual robustness and multicipital flowering stem. But, clearly, the large 

 marjority of individuals of E. lackscbewitzii are morphologically most similar to each other or to 

 E. ochroleucus. 



Chromosome count and pollen SEM 



Chromosome numbers for E. lackscbewitzii were unobtainable; no pollen was found in any of the 

 capitula examined. Seed germination was likewise unsuccessfijl, as achenes were found to be too 

 immature to germinate. 



A single pollen grain of E. lackscbewitzii was photomicrographed and found to be abnormal 

 (Figure 6), while pollen grains of E. simplex and E. ochroleucus were typical (Figures 7 and 8) of 

 f the Astereae tribe of Asteraceae (Skvarla, et al., 1977), E. radicatus pollen has not been 

 photomicrographed to date. 



