found: Work cat: Recovery strategy for the branched bartonia (Bartonia paniculata ssp. paniculata) in Canada, 2017:page 2 ("Branched Bartonia has three currently recognized subspecies: Bartonia paniculata paniculata, B.p. texana, and B.p. iodandra. Only subspecies B.p. paniculata occurs in Canada, and mention of Branched Bartonia throughout this recovery strategy refers to subspecies B.p. paniculata, unless otherwise stated. This species is also referred to as Panicled Screwstem or Twining Screwstem, and the names may be used to refer to other subspecies (e.g., ssp. texana) that do not occur in Canada")
found: ITIS website, June 29, 2018:(Bartonia paniculata, Common name - twining screwstem; Subspecies - Bartonia paniculata ssp. iodandra (twining screwstem), Bartonia paniculata ssp. paniculata (twining screwstem); Genus - Bartonia, Family - Gentianaceae, Order - Gentianales, Class - Magnoliopsida, Division - Tracheophyta, Kingdom - Plantae)
found: PLANTS database website, June 29, 2018:(Bartonia paniculata, twining screwstem; Subspecies - Bartonia paniculata ssp. iodandra (twining screwstem), Bartonia paniculata ssp. paniculata (twining screwstem); Genus - Bartonia (screwstem), Family - Gentianaceae, Order - Gentianales, Class - Magnoliopsida, Division - Magnoliophyta, Kingdom - Plantae)