Towards sustainable harvesting of seneca snakeroot, Polygala senega L., on Manitoba Hydro rights-of-way

Abstract

The root of seneca snakeroot (Polygala senega L.), a perennial herb native to North America, has been used medicinally by Europeans for over 300 years. Seneca snakeroot is valued, particularly for its expectorant properties. Lately, the demand for wild seneca root has increased due to a escalation of interest in herbal medicine. Increased harvesting pressure has raised concerns as to the sustainability of native seneca snakeroot populations in Manitoba. This study investigated the biology, ecology, ethnobotany and economics of seneca snakeroot in order to address the question of the sustainability of seneca snakeroot populations. Ten study sites were sampled along Manitoba Hydro rights-of-way in the northern Interlake and Grand Rapids region to obtain baseline information on the population biology and ecology of seneca snakeroot. The baseline information revealed that seneca snakeroot populations in the Northern Interlake region seem to be successfully regenerating under current harvesting pressures. Investigations into the economics of seneca snakeroot revealed that an entire network of people is involved in the seneca industry including; diggers, exporters, brokers, pharmaceutical companies and consumers. Results from the germination and propagation experiments indicate that seneca snakeroot can be propagated either vegetatively or by seed. Two seed germination and two vegetative propagation methods proved successful. The information gained from the study lead to four recommendations concerning the sustainability of seneca snakeroot. The cultivation of seneca snakeroot should be promoted in order to relieve harvesting pressure on existing wild populations. Harvesting and marketing strategies should be developed in Manitoba for the direct benefit of local harvesters and exporters. The rights-of-way in the Interlake region should be maintained (using mechanical vegetation removal) as they provide excellent habitats for snakeroot populations. Experiments and long-term monitoring of seneca populations could be continued utilizing the semi-permanent plots of this study.