ABSTRACT 



Preliminary data obtained from chloroplast DNA and morphological analyses suggest that Erigeron 

 lackscbewitzii is an apomictic race of the predominantly sexual species, E. ochroleucus. 

 Specifically the hypothesis that outcrossing races of E. ochroleucus bud off apomictic races, one of 

 which is E. lackscbewitzii, and another possibly E. radicatus, will be evaluated with more indepth 

 genetic and morphological analyses. Furthermore, the potential inclusion into synonymy of E. 

 radicatus with E. ochroleucus var. scribneri will be evaluated. 



EMTRODUCTION 



Nesom and Weber (1983) proposed a new alpine species, Erigeron lackscbewitzii, endemic to an 

 area largely within the Bob Marshall and Scapegoat Wildernesses of northwestern Montana. The 

 authors suggested that E. lackscbewitzii may be derived from either E. simplex Greene, a 

 widespread sympatric species, or the southern alpine race of E. grandiflorus Hook., a species 

 distributed from the Beartooth Plateau south into New Mexico and west into the Great Basin 

 (Spongberg, 1972). Dom (1984 and personal communication) suggests E. lackscbewitzii is 

 synonymous with E. ochroleucus Nutt., specifically E. ochroleucus var. scribneri (Canby) Cronq. 



This preliminary report addresses the taxonomic status of E. lackscbewitzii and represents the 

 initial step in a comprehensive study of the taxonomy of this putative species for the Montana 

 Natural Heritage Program. The report focuses on comparative morphological and chloroplast 

 DNA (cpDNA) studies, chromosome counts, and SEM microscopy to elucidate the relationship of 

 E. lackscbewitzii to E. simplex , E. ochroleucus and other putative close relatives. 



Erigeron radicatus Hoolc has been included in this paper in response to my preliminary findings 

 which suggest that this species is closely related to, and may be a variety of, E. ochroleucus. 

 Arthur Cronquist's personal communication to Klaus Lackschewitz auestioned the taxonomic 

 distinction of E. radicatus (Lackschewitz, personal communication), while Peter Lesica intimates 

 that E. radicatus may be indistinguishable morphologically from E. ochroleucus var. scribneri 

 (Lesica, p^ersonal communication). 



METHODS AND MATERIALS 



Specimens for cpDNA screening were obtained from eight sites in western Montana (Table 1). 

 Whole plants were either pressed and dried or placed in plastic bags on ice and later stored in a 

 -80°C freezer. 



Leaves were ground in CTAB DNA extraction buffer (Doyle et al., 1990). Total DNA from nine 

 specimens representing six species was digested with 12 restriction endonucleases having six-base 

 nucleotide recognition sequences. These included BamHI, BcR, Oral, Ascl, Sad, Xhol, EcoRJ, 

 EcoRV, Nsil, Seal, Stul, and Xbal. Fragments were separated in 0.9% agaroseATBE gels.' 

 Erigeron lackscbewitzii, E. ochroleucus, and £. radicatus, as the ingroup, were compared against 

 the outgroup E. simplex, E. speciosus, and E. caespitosus in order to polarize site mutation. 



Restriction site analysis, including Southern blotting, nick-translation, hybridization to radioactive 

 probes, and autoradiography basically foUow Sytsma and Gottlieb (1986). Cloned fragments from 

 the large single copy region of the cpDNA library of Petunia (provided by Jeff Palmer) and from 

 the nuclear nbosomal repeat of Glycine max (PGMRl, provided by Liz Zimmer) were used in the 

 hybndization experiments. Figure 1 illustrates location of cpDNA probe regions. 



Morphological analyses were based on 30 quantitative and 27 qualitative characters. These 

 attiibutes were scored for each of 73 individual plants representing four species: E. lackscbewitzii 

 (34 specimens), E. ochroleucus var. scribneri (9 specimens), E. radicatus (11 specimens), and 



