Friday, June 14, 2019

Giant Vetch, A “sketchy vetch-pea” or a tasty edible?


Last week I paddled down the North Fork of the Skagit River to Craft Island with my brother Christian and Lindsey for a barbeque on the beach. I found a healthy population of Giant Vetch (Vicia nigricans ssp gigantea) growing along the shoreline with peas ripe for the picking. Aware of the Kwakwaka’wakw use of this plant for food, I decided to give it a taste. For years I have approached all wild peas with trepidation because of lore among the wild food community that they are toxic. However, the time was also ripe for evaluating the facts and conducting a cautious experiment. But first, the plant:


Description
Giant vetch is our most robust species of vetch with herbaceous stems that can clamber up grass and other vegetation to a height of 3-6 feet. The stems, leaves, and flowers are all minutely haired to hairless. Leaves are pinnately compound with 18-30 leaflets that are more or less opposite. Each leaf has a large stipule at the base and a well-developed tendril at the tip which divides into 3-7 branches that enable the plant to trellis up surrounding vegetation. Flowers are irregular but lack obvious petals being fused into a tubular corolla with a conspicuous boomerang-like bend. The corolla is 5/8-3/4” long, creamy white at the base and pink at the tips when fresh but fading quickly to orange or light brown. The calyx is half the length of the corolla, purple and green in color, and crowned with prominent triangular lobes. Flowers are borne on a compact raceme of 7-20 flowers arising from the leaf axils on leafless stalks (peduncles) that are several times longer than the raceme. The peas develop inside pods, which contain 5-8 peas. Pods are initially green and flattened but swell to nearly cylindrical as the peas mature. Each pea is roughly the size of a garden pea.
 
Habitat and Range
Giant Vetch is predominantly a coastal species found in salt marshes, sand and gravel beaches, as well as rocky shorelines in the transition zone where driftwood often accumulates, from the Channel Islands in California northward to Sitka Alaska. In Washington and Oregon, it also grows on river levees, lakeshores, and upland environments with ample sunlight and enough disturbance to keep woody plants at bay. For example, I occasionally see it on rural roads and powerline corridors that are mowed less than once a year.

Ethnobotany
Despite the sizeable peas, the ethnobotanical literature for Giant Vetch is minimal. The earliest record comes from the botanist George Suckley and ethnographer George Gibbs (Suckley and Coooper 1860), who explored the route of the future Northern Pacific Railroad line from the Cascade Crest to the Puget Sound in 1854 and 1855. They noted that Giant Vetch was abundant at Fort Steilacoom (just south of Tacoma WA) and describe the seeds as "eatable." Shortly thereafter, Robert Brown (1868) reports that “the seeds… are eaten,” but fails to mention by whom and how they are prepared. Leslie Haskins (1934), the author of an early wildflower book provides an equally ambiguous account stating that the seeds are edible and used by the Indians, but this may just be a reference to earlier botanical works and not based on personal observation. Another historical account with little meaning comes from Edward Sturtevant, the pioneering agronomist and author of Sturtevant’s Edible Plants of the World. He passes on what appears to be a personal anecdote from Asa Gray, who many consider to be the father of American Botany. Gray “remarks that the seeds are eatable, when young, like green peas (Hedrick 1919).

The most reliable accounts come from two Kwakwaka’wakw elders interviewed in Fort Rupert, BC by Nancy Turner in 1969, who reported that the seeds are roasted in their pods over a fire before being eaten. Helen Norton (1981) also documented the use of Giant Vetch among the Kaigani Haida, but her account is a little problematic. Several consultants told Norton that the peas were boiled and eaten after the pods dried, but one woman was sure that they were unsafe to eat.

In a part of the world where very few seeds are traditionally eaten, this dearth of ethnobotanical literature should be expected. However, I am surprised that Giant vetch is not traditionally used in California, where seed foods are commonly gathered.


My experiment
On June 12, 2019 I collected a dozen Giant Vetch racemes with pods at different stages of ripeness from the northwest side of Craft Island in Skagit County, WA. The next morning, I shelled seed pods at each stage of ripeness to assess the differences. I found the pods that that were still bright green contained seeds that were three quarters the size of the mature seeds or smaller; pods that were just starting to yellow contained peas that were green, plump, and tender looking; and pods that had started to blacken contained hard, brown seeds. I then targeted those pods with peas that were full sized or nearly so, and still bright green. The size of the seeds could easily be judged by the thickness of the pod. I placed about 30 peas in two cups of water and boiled them for 3 minutes. Then I drained the water, and ate the Giant Vetch peas with a fork and knife. They tasted very similar to Garden Peas (Pisum sativum) but were not as sweet. There texture was also very similar, but slightly more fibrous. I monitored my health for the rest of the day and did not notice any ill effects.


Toxicity
Populations of Common Vetch (Vicia sativa) and other members of the Vicia genus have been implicated in both human and livestock poisoning (Turner and Szczawinski 1991). Lupines (Lupinus spp.), are also members of the pea family (Fabaceae) with distinctive pea pod looking fruits. Lupines contain many toxic alkaloids, especially in the seeds and pods. A few species also contain enzyme inhibitors (Turner and Szczawinski 1991). I could find no accounts of Giant Vetch poisoning in humans or livestock.


Conclusions
Having had very positive first taste, I was left wondering why Giant Vetch peas lack a richer history of use. My conclusion is that the plant has three strikes against it: (1) Giant Vetch has poisonous relatives; (2) it has a very limited range along the coast, and (3) much of its range occurs in areas were small seeds were only marginally used by Indigenous peoples.

Please comment with your experiences if you have eaten this plant.


References

Brown, Robert 1868. “On the Vegetable Products, used by the North-West American Indians as Food and Medicine, in the Arts and in Superstitious Rites.

Consortium of Pacific Northwest Herbaria, Vicia nigricans account.

Haskin, Leslie L. 1934. Wild Flowers of the Pacific Coast.

Hederick, U.P. 1919. Sturtevant’s Notes on Edible Plants.

North, Helen 1981. "Plant use in Ktaigani Haida Culture: Correction of an Ethnohistorical Oversight." Economic Botany, Vol 35, No 4.

Suckley, Goerge and James Graham Cooper 1860. "The Natural History of Washington Territory and Oregon, with much relating to Minnesota, Nebraska, Kansas, Utah, and California, being those parts of the final reports on the Survey of the Northern Pacific Railroad Route, relating to the Natural History of the Regions Explored, with Full Catalogues and Descriptions. Bailliere Brothers, New York


Turner, Nancy J. and Marcus Bell 1973. “Ethnobotany of the Southern Kwakiutl Indians of British Columbia.” Economic Botany, Vol 27, No 3.

Turner, Nancy J. and Adam Szczawinski 1991. Common Poisonous Plants and Mushrooms of North America. Timber Press, Portland OR.

WTU Image Gallery at the Burke Museum Herbarium, Vicia nigricans account