Vitaceae

Grape Family

Canyon Grape

FAMILY: Grape family (Vitaceae) – Vitis genus.

SPECIES: Canyon grape (Vitis arizonica Engelm.).

TO UTILIZE AS FOOD: Leaves and fruits of canyon grape vines are edible fresh or cooked. Most species of grapes are native to North America. Only canyon grape is likely to be found in the Southwest and southern Great Basin.

Canyon grape (V. arizonica) vines produce masses of leaves that taste pleasantly acidic and moderately astringent. A fruity accent may also be apparent. The tangy flavor comes from malic, oxalic, and tartaric acids. Canyon grape leaves are suitable for soups or salads. They make an excellent wrap for whole grains, onions, peppers, and beans. The texture is firm, chewable, and nonfibrous. Even the leafstalks are chewable. Fresh and cooked leaves taste similar. Gathering a supply is easy. Canyon grape vines can quickly take over riparian areas, sprawling over shrubs, climbing on trees, and generally making the place look like a jungle. Of course, this scene is a welcome sight to hungry foragers. Canyon grapes are reddish-purple with dusty white coatings and about 4-7 mm in diameter. They rank among the sweetest and tartest fruits of the Southwest. The texture is sharply uncomfortable, almost like fine-grained sandpaper. It’s similar to the feeling caused by calcium oxalates, but not so intense. Canyon grapes contain tartaric acid. Consuming excessive amounts of tartaric acid can be harmful, but the amount of this acid naturally present in canyon grapes is unlikely to cause harm. The Food and Drug Administration lists tartaric acid among substances “generally recognized as safe” and allows its use as a food additive for many different purposes. Tartaric acid within the grapes can be eliminated, or at least reduced, through a process called precipitation. This is done by: covering the grapes with water, mashing, straining, and bringing the juice to a boil. As the juice cools, sand-like clumps of tartaric acid precipitate out of the juice and settle on the bottom. These clumps can then be separated by carefully pouring off the juice. This process has limitations, but it definitely helps. Wild canyon grapes have seeds that contribute a firm crunch along with plenty of calories and nutrients. Removing them is unnecessary. The seeds come in a variety of colors and fill about half the volume. They add a gritty texture to the overall experience that some people may find objectionable. Tiny fragments of seeds can always be spit out after chewing the grapes. Pressing canyon grapes doesn’t yield much juice. Drying whole grapes makes crunchy little raisins tasting similar to the fresh fruits. Canyon grapes are found throughout the Southwest from July to October, especially in canyons, as a forager might expect considering the name.

NOTES: Fruits of a closely related vine called Virginia creeper, woodbine, or five-leaf ivy (Parthenocissus quinquefolia) look very similar to grapes. They even taste like grapes, but they’re reported to be poisonous (Tull 2013 p. 184). They’re also reported to be edible (Blankenship 1905 p. 6, cited as Ampelopsis quinquefolia). According to Blankenship, “The ripe fruit is collected and eaten, like grapes, by the Sioux.” Delena Tull states that the ripe fruits contain excessive amounts of oxalic acid that can cause kidney damage. Lee Allen Peterson (p. 180) and many other authors also state that the fruits are poisonous, even deadly if eaten in large amounts. Virginia creeper and grapes are both members of the grape family. Fortunately, the leaves provide an obvious difference. Wild grape vines always have simple leaves. They’re never compound or deeply cut to the bases. In contrast, leaves of Virginia creeper are palmately compound with 3-5 leaflets.

IDENTIFICATION: The Vitis genus is represented by about 20 species in the United States, of which only canyon grape (V. arizonica) is common in the Southwest. A few others barely enter the region.

Description of canyon grape (Vitis arizonica): FORM climbing vine up to several meters long bearing well-developed tendrils opposite to the leaves; stems woody at the bases; LEAVES simple; alternate; stalked; blades rounded in outline and with 3-5 shallow palmate lobes; margins coarsely toothed; surfaces normally hairy in youth and becoming hairless in age; FLOWERS regular, functionally unisexual, ovary superior, and arranged in dense clusters opposite to the leaves; sepals 5, minute; petals 5, greenish-yellowish-white, free at the bases and united at the tips; stamens 5; FRUITS grapes sweet, tart, globe-shaped, reddish-purple, and dusty; HABITAT moist canyons, streams, and natural springs over a wide range of elevations; California to Texas; blooming April to July.

REFERENCES: Canyon grape (Vitis arizonica): leaves Couplan (pp. 296-298); fruits Couplan (pp. 296-298) and Hodgson (pp. 244-246).