Lacis.
Botanical name:
Lacis sp.? Podostemaceae.
Henfrey says some species are used for food on the Rio Negro and other parts of South America.
Sturtevant's Edible Plants of the World, 1919, was edited by U. P. Hedrick.
A herbal distance course
Henriette's herbal is one of the oldest and largest herbal medicine sites on the net. It's been online since 1995, and is run by Henriette Kress, a herbalist in Helsinki, Finland.