 Since 1998 , an American botanist , Austin Mast , has been publishing results of ongoing cladistic analyses of DNA sequence data for the subtribe Banksiinae . His analyses suggest a phylogeny that is very greatly different from George 's arrangement , and somewhat different from Thiele and Ladiges ' . With respect to B. violacea , Mast 's results agree with its placement near B. laricina and B. incana , placing it in a clade with these two species and B. sphaerocarpa var. dolichostyla ( treated at species rank as B. dolichostyla ) . However , Thiele 's B. subseries Longistyles appears to be polyphyletic , as do both definitions of B. ser . Abietinae — that is , none form a natural grouping . 
 Since 1998 , an American botanist , Austin Mast , <a href='uninflect' title='1'><mark>has</mark></a> been publishing results of ongoing cladistic analyses of DNA sequence data for the subtribe Banksiinae . His analyses suggest a phylogeny <a href='null_relcl' title='2'><mark>that</mark></a><a href='drop_aux' title='3'><mark>is</mark></a>very greatly different from George <a href='null_genetive' title='4'><mark>'s</mark></a>arrangement , and somewhat different from Thiele and Ladiges ' . With respect to B. violacea , Mast <a href='null_genetive' title='5'><mark>'s</mark></a>results agree with its placement near B. laricina and B. incana , placing it in a clade with these two species and B. sphaerocarpa var. dolichostyla ( treated at species rank as B. dolichostyla ) . However , Thiele <a href='null_genetive' title='6'><mark>'s</mark></a>B. subseries Longistyles <a href='uninflect' title='7'><mark>appears</mark></a> to be polyphyletic , as do both definitions of B. ser . Abietinae — that is , none form a natural grouping . 
Since 1998 , an American botanist , Austin Mast , have been publishing results of ongoing cladistic analyses of DNA sequence data fir da subtribe Banksiinae . His analyses suggest a phylogeny very greatly diff from George  arrangement , and somewhat different from Thiele and Ladiges ' . With respect to B. violacea , Mast  results agree wit its placement near B. laricina and B. incana , placing it in a clade wwiddese two species and B. sphaerocarpa var. dolichostyla ( treated at species rank as B. dolichostyla ) . However , Thiele  B. subseries Longistyles appear to be polyphyletic , as do both definitions of B. ser . Abietinae — dat is , none form a natural grouping .