The Yellow Passionflower (Passiflora lutea, right photo) is found in June-September in mixed woodlands and thickets. The Purple Passionflower (P. incarnate, left photo) is found mostly in fields, roadsides and fencerows in July-August. The purple species is fairly common throughout Pittsylvania County, Virginia; the yellow species is somewhat rare within the county.
It is interesting how the two species, belonging to the same genus, have such conspicuous floral organs.
See also further information about the Purple Passionflower, and this pair of photographs in in larger format.
Copyright © 2007 William T. Hathaway.