Ethnobotany

Three species of Hedysarum grow on the prairies. They are sometimes referred to as sweet-vetch or sweet-broom. Typically, their pea-like flowers grow in long slender wand-like clusters. Northern hedysarum’s reddish purple flowers often grow in one sided clusters up to 15 cm long. When they go to seed, the pod-like fruit is in segments with one seed in each segment. 

Kershaw reports that the roots of some species were an important food for many First Nations people. Young roots have a sweet licorice flavour if eaten raw, and taste like carrots if cooked. (134)

Wilkinson cautions that the roots of this species are “extremely poisonous.” (115) But Kershaw offers this explanation for the plant’s reputation: 

In 1852, Sir John Richardson, an Arctic explorer, reported that all of his men who mistook northern sweet-vetch for the edible alpine sweet-vetch became ill. However, this story appears to be the only reference to the plant’s toxicity. It is possible that toxicity varies with location, but this case of poisoning could also have resulted from confusion with another similar-looking plant, such as locoweed. (135)

Botany

Growth habit and range: This is an erect to decumbent, perennial herbaceous plant which is occasionally found in moist sites in prairies and ravines. This plant grows to a height of 20–50 cm.

Description: The stems are thin and weak. The leaves are alternate, pinnately compound and comprised of hairy, ovoid leaflets which number 9–13 per leaf. Flowering occurs in June and July. The pea-like flowers are borne in a 15 cm terminal raceme of 12–20 individual flowers which are red-purple in colour and are somewhat reflexed or drooping. Each flower measures 12–15 mm in length. The fruit is a smooth pod measuring 2–3 cm in length which is divided into a number of compartments called ‘loments’ by constrictions between the seeds. The seeds are dark coloured, kidney-shaped and up to 3 mm in length. The roots of this plant are poisonous.

References

• Kershaw, Linda. 2000. Edible and Medicinal Plants of the Rockies. Lone Pine Publishing, AB.

• Wilkinson, Kathleen. 1999. Wildflowers of Alberta: A Guide to Common Wildflowers and Other Herbaceous Plants. University of Alberta Press and Lone Pine Publishing, AB.