High Quality Content by WIKIPEDIA articles! Xylothamia is a genus of flowering plants in the daisy 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. The relationships of the other five species is not quite as clear. All nine species do belong in the subtribe Solidagininae.