Monday, July 30, 2012

Black-eyed Susans rarely actually take a beating

Species name: Rudbeckia hirta

Common name: black-eyed Susan, yellow ox-eyed daisy

Location: Ontario

Black-eyed Susans are spectacular flowering plants native to southeastern Canada all the way south to Florida and Texas in the United States. There are four sub-species designating populations of plants in various locations, since the species range has become non-continuous due to land use change. It's an incredibly successful competitor and thrives in disturbed areas, so is often the first plant to colonize a recently abandoned field. Despite being able to out-compete almost all early successional field species, it does poorly in shade and so once shrubs and trees start to colonize the area it will quickly die out (or only remain in small patches). Anyone who has ever planted this plant in their garden knows about its ability to quickly colonize an area; keeping a patch of Black-eyed Susans under control feels like a losing battle (partially because, by definition, backyard gardens are disturbed areas which means this plant does exceptionally well).

Medicinally, this plant was used in almost the same way as the purple coneflower, Echinacea. The Ojibwa people used a paste-like liquid made from ground roots mixed with water as a treatment for snake bites, and made a tea-like infusion from the leaves and roots as a treatment for worms in children. The Menominee and Potawatomi people used the natural diuretic properties of this plant to flush toxins from the body. Because this diuretic effect is real, caution should be used when using this plant as an herbal medicine; over-use can result in severe dehydration which requires hospitalization. If this is not caught in time, permanent kidney damage or even death can occur.