Xylothamia
Introduction '''''Xylothamia''''', the '''desert goldenrods''', is a genus of flowering plants in the family Asteraceae. Until 2003, it was held to contain nine species of shrubs native to deserts of Mexico and the southwestern United States. However, it seems to contain at least two groups. Four species are related to ''Gundlachia'' and may be moved to that genus. Plants of the World Online (part of the Royal Botanic Gardens, Kew) class it as a synonym of ''Gundlachia''. The relationships of the other five species is not quite as clear. All nine species do belong in the subtribe Solidagininae.
Species The following four species, including the type species ''Xylothamia triantha'', are related to each other and to ''Gundlachia'':*''Xylothamia diffusa''*''Xylothamia riskindii''*''Xylothamia triantha''*''Xylothamia truncata''Kew lists ''Gundlachia diffusa'' ''Gundlachia triantha'' and ''Gundlachia truncata''.The following three species are related to each other and to ''Bigelowia'' and ''Thurovia'':*''Xylothamia pseudobaccharis''*''Xylothamia parrasana''*''Xylothamia purpusii''Due to molecular evidence, these 3 species were transferred to genus ''Medranoa'' in 2007; as ''Medranoa pseudobaccharis'', ''Medranoa parrasana'' and ''Medranoa purpusii''.The following two species are related to each other:*''Xylothamia johnstonii''*''Xylothamia palmeri''
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