Helix Janthina and Violacea described, xii.
"Robert Kerr's General History and Collection of Voyages and Travels, Volume 18" by William Stevenson
Pinguicula Violacea: Violet-coloured Butterwort, (instead of 'vulgaris,') the common English and Swiss kind above noticed.
"Proserpina, Volume 2" by John Ruskin
Flowers greenish, nodding 1a, in =VIOLACEAE=, p. 75.
"The Plants of Michigan" by Henry Allan Gleason