Bartonia

These often pale, essentially leafless plants obviously derive their nutrition from other plants, but whether or not with the aid of a fungus seems to be unknown.

1. Mid-cauline leaves alternate; anthers ca. 0.3โ€“0.5 mm long.

B. paniculata

1. Mid-cauline leaves opposite or subopposite; anthers ca. 0.5โ€“0.9 (โ€“1.1) mm long.

B. virginica

All species found in Bartonia

Bartonia paniculataPANICLED SCREW-STEM 
Bartonia virginicaSCREW-STEM 

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. May 22, 2017. http://michiganflora.net/genus.aspx?id=Bartonia.