Family | Scientific Name | Common Name | Habitat | Distribution | Image |
Gentianaceae | Bartonia paniculata ssp. iodandra | Purple Screwstem | Wet, peaty hollows, sphagnous bogs, peaty turf, and damp lake
shores in sandy soil. | Newfoundland south to Long Island, NY, and perhaps NJ. | 
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Gentianaceae | Bartonia paniculata ssp. paniculata | Screwstem Bartonia | Swamps, bogs, pocosins, pocosin ecotones, sphagnous seepages, sinkhole ponds. | Ssp. paniculata ranges from MA south to c. peninsular FL and west to e. TX, chiefly on the Coastal Plain, but with scattered occurrences inland, to c. VA, e. WV (Vanderhorst et al. 2013), w. NC, KY, and AR. | 
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Gentianaceae | Bartonia paniculata ssp. texana | Texas Screwstem | Baygalls, acid seepages. | Ssp. texana is endemic to the West Gulf Coastal Plain of w. LA and e. TX, where it is more-or-less sympatric with ssp. paniculata (Mathews et al. 2009). | 
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Gentianaceae | Bartonia texana | | | | |
Gentianaceae | Bartonia verna | Spring Bartonia, White Bartonia | Wet pine savannas, shores of Coastal Plain depression ponds, interdune swales, other moist sands. | VA (one site known from City of Virginia Beach) (Belden et al. 2004) and se. NC (Carteret County) south to s. FL, west to se. TX. | 
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Gentianaceae | Bartonia virginica | Virginia Bartonia, Yellow Bartonia | Bogs, swamps, pine savannas, pocosin ecotones, pocosins, dune swales. | NS and QC west to WI, south to s. FL, LA, and e. TX (Singhurst & Bridges 2024). | 
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