Veiny Pea is one of few late May - early June blooming plants in the Upland Prairie Garden. This native perennial climbing vine has 4-angled stems, without wings, that sprawl and climb on other plants. The stems can grow up to 3 feet long, but on the Prairie are usually much shorter.
Leaves are alternate and pinnately divided with (usually) 8 to 12 (14) ovate stalkless leaflets arranged asymmetrically (this is - not opposite) on the leaf stalk. There is a branching tendril at the leaf tip for climbing and at the base of the leaf is a stipule (small leaf-like growth) that has somewhat of an arrow shape; it partially clasps the stem and has two pointed lobes aligned with the leaf stalk. Both the stem and the stipule can have fine hair.
The inflorescence is a dense stalked unbranched cluster (a raceme) that rises from the leaf axils. The individual flowers number 6 to 26 and are on short stalks.
Flowers are 5-parted, about 3/4 inch long with a calyx that is greenish on the bottom, shading to pinkish on the top with deeper color veining. The calyx is about 1/3 the length of the total flower; it has 5 lobes at the top edge and has dense fine hair. The corolla is typical of Pea family flowers. It has petals that shade from white to reddish pink; with age the pink color fades to bluish-white. One petal of the corolla turns upward forming the larger banner petal. It has a notch at the top and is the most colorful, with deeper color veining being prominent. The other petals are usually whitish - two narrow laterals that fold downward and forward and between the laterals are two joined keel petals within which are the reproductive parts - ten stamens and a single style of the one-carpel ovary.
Seed: Flowers mature to a linear seed pod resembling the garden pea, but flat. The pod splits into two sections at maturity to release fruit, much like your typical garden pea pod. Seeds are flattened, 3 to 4 mm long and 2 to 3 mm wide. Dry seeds would need scarification before planting.
Habitat: The plant spreads by rootstocks (rhizomes) and like most vetches, care should be taken in planting this in the home garden. It is found in open woods and prairies in dry to moderate moisture conditions. Full sun is preferred.
Names: The genus Lathyrus, is from the Greek word lathyros, meaning 'pea'. The species venosus, means 'prominently veined' referring the calyx and the banner petal of the corolla. The author name for the plant classification is two-part: First to classify was ‘Muhl’ which refers to Gotthilf Heinrich Ernst Muhlenberg (1753-1815) American Botanist who produced several catalogues of plants after retiring as a Lutheran pastor. His work was revised by the other author ‘Willd.’ - Carl Ludwig Willdenow (1765-1812), German botanist, a founder of the study of the geographic distribution of plants. He was director and curator of the Botanic Garden of Berlin.
Comparison: This vetch is similar in form and description to American Vetch, Vicia americana - the key difference in immediately distinguishing the two is the leaf stipule, which in V. americana has a sharp tip and three sharp teeth. American Vetch also has a looser flower cluster with fewer flowers. Another member of the Vicia genus found in Minnesota is Hairy Vetch, V. villosa. There the flower raceme is longer, the calyx is very hairy and swollen at the base, the plant is much more hairy overall and the stipule of the leaf is more ovate. Another Lathyrus is L. latifolius, Everlasting Pea, but there there are only two leaflets per leaf and the banner petal is much larger. Lathyrus palustris, Marsh Pea, also has a tendril at the tip and pink flowers but the leaflets are very long and narrow and the stipules are different.
Above: The flower racemes of mid-May to June. In the 2nd photo you see that as the older unfertilized flowers fall away from the bottom of the cluster, a stalk scar remains on the raceme stem.
Below: Note the branched tendril at end of the leaf. Individual leaflets are not paired on the leaf stem (asymmetrical) and not stalked.
Below: 1st photo - Detail of the unstalked leaflets. 2nd photo - The unique stipule with two arrow shaped points at the base of the leaf stalk.
Below: 1st photo - The raceme has 6 to 26 flowers. The calyx is hairy and the calyx and banner petal has rich veining. 2nd photo - The fruit is a long seed pod, much like a garden pea, but flattened.
Notes: Veiny Pea is indigenous to the Garden area. Eloise Butler catalogued it on May 31, 1907. She planted additional plants on June 15, 1910 with plants obtained in Glenwood Park (which surrounded the Garden). It is native throughout Minnesota except for a handful of scattered counties. It is considered endangered in several Midwest and eastern states. Within North America the plant is found primarily in the eastern 2/3rds of the continent with the exception of New England and the Canadian Maritime Provinces.
There are six species of Lathyrus found in Minnesota: L. maritimus, Beach Pea; L. ochroleucus, Cream Pea or Pale Vetchling; L. palustris, Marsh Vetchling; and L. venosus, Veiny Pea, are all considered native. Two others are introduced: L. latifolius, Everlasting Pea; and L. tuberosus, Tuberous Vetchling. Only L. venosus and L. ochroleucus are found in the Garden.
Lore: Frances Densmore (Ref. #5) researched how the Native Americans of Minnesota used wild plants for food, medicine & crafts. Her research was reported in the 44th Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1926-27. Her work was done among then living members of the Chippewa.
She refers to the plant with the common name of "Wild Pea" and the botanical name of Lathyrus venosus Muhl. The part of the plant used was the root, where it was dried and then powdered. A decoction of this root was taken internally to control convulsions. It was also taken as a tonic and stimulant. For bleeding from wounds, the root was boiled and used in a poultice. The decoction could also be used in large doses as an emetic (induces vomiting) if blood had accumulated inside a person.
In view of these beliefs as to the root's benefits it is not surprising that the dried root was also considered as a charm and was carried on the person to insure successful outcome of difficulties (and if difficulties resulted in wounds - one had the medicine at hand.)
Most of Densmore's findings on this plant were gathered from certain people on the White Earth Reservation. Her report is available as a separate publication and is listed in the "Reference List" link below.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"