Wild Cucumber hides a bit in the landscape until mid-summer when the annual herbaceous vine accelerates its climb from the garden floor. It grows quickly with many 3–forked tendrils clinging to support plants and soon it has spread itself over a large area. The tendrils arise at the leaf nodes, but 90 degrees to the leaf stem. These are touch sensitive and contract to a coil when they contact a support. The stem is hollow, flexible, and 5-ridged.
Leaves are thin, rough on each side, on long stalks,with a heart-shaped base and 3 to 7 triangular lobes, mostly 5.
The inflorescence is a long erect raceme rising from the leaf axils.
Flowers: After vining, suddenly there is a burst of white as the 6-part male flowers bloom. The flowers are of separate sexes (monoecious). Both sexes are showy with 6 long thin greenish-white petals opening to a star formation. These always seem to have a partial twist. The staminate (male) flowers have 3 stamens with yellow s-shaped anthers that are united into a column. The margins of the petals have glandular hairs. Mixed in at the base of the raceme, but developing slightly later from the staminate flowers are 1 to 4 of the pistillate (female) flowers. These also have gland-tipped hairs and beneath the petals is the green 6-lobed ovary that is softly prickly outside making it look larger than it is. The style has a blunt tip. This ratio of male to female is why after seeing so many white flowers one sees only a few of the cucumber fruits.
Fruits: These are green oval inflated capsules, usually about 2 inches long, with longitudinal veins, covered with soft prickles and containing four chambers, each of which produces a flat brown seed. The prickles are tipped with a small gland when young. The capsule opens from the bottom in autumn releasing the seeds. Dry seeds are about 15 x 7 mm (5/16 x 5/8 inch) The seed capsule is quite conspicuous as the vine is usually draped over other plants or woodpiles, etc., and the leaves have fallen away leaving only the green to brown capsule hanging from the bare vine. The seeds require 60 days of cold stratification for germination.
Habitat: Wild Cucumber grows in a variety of soils from moist to dry woodlands, but sun is required.
Names: The genus name is made up of two Greek words - echinos, which is difficult to discern as it seems to mean "hedgehog" and probable refers to the spines on the fruit capsule and cystis, which means "bladder" - this is easy to discern from the capsule shape. The species name lobata is Latin for "lobed" and can refer to the lobed ovary and the resulting lobed fruit.
The author names for the plant classification are: The first to classify was ‘Michx.’, which is for Andre Michaux (1746-1802), French botanist who made many exploring expeditions in the U.S. collecting and cataloging many species. His notes were later used by his son, Francois, who with Thomas Nuttall published the multi-volume North American Sylva. Michaux's work was advanced by ‘Torr.’ who is John Torrey (1796-1873), American botanist, who, among many things, taught Asa Gray, contributed to the early parts of Flora of North America and who published the reports of plants collected by John C. Fremont’s 1842 and 1843-1844 Exploring Expeditions to the Rocky Mountains. Collaborating with him was his pupil, ‘A.Gray’, which is Asa Gray (1810-1888), American botanist, Professor of Natural History at Harvard and instrumental in unifying plant knowledge of North America and author of Gray’s Manual - Manual of the Botany of the Northern United States, from New England to Wisconsin and South to Ohio and Pennsylvania Inclusive.
Comparisons: There is another plant called One-seeded Bur Cucumber, Sicyos angulatus, that has a similar looking capsule, but different flowers and leaves and less frequently seen in Minnesota.
Above: 1st and 2nd photos - The long flower racemes of Wild Cucumber are erect at the beginning of the flowering period. Male staminate flowers predominate. 3rd photo - The long stalked leaves are usually found with 5 triangular lobes, but can have 3 to 7. Note the tendrils.
Below: See description above.
Below: 1st photo - A male flower with the yellow anthers of the 3 stamens touching together as a central column. Note the glandular hair on the petals. 2nd photo - A female flower. Note that the 6-lobed ovary is beneath the petals and covered with soft prickly projections.
Below: 1st photo - A female flower. Note the blunt tip of the style. 2nd photo - The green seed capsule with soft prickles tipped with small glands.
Below: 1st photo - The seed capsule after the seeds have dropped and one seed. 2nd photo - The dried seed capsule, note the lace-like texture of the inside.
Below: Historical Garden Photo - Wild Cucumber flowers on Aug. 17, 1952. Photo from a Kodachrome by Garden Curator Martha Crone. Photo courtesy Minnesota Historical Society, Martha Crone Collection.
Notes: Wild Cucumber is indigenous to the Garden but now an ex-resident. Eloise Butler noted its presence on May 25, 1907 and planted seedlings in 1916. It was listed on Martha Crone's 1951 Garden census - she had also planted it in 1947 - but absent by the time of the 1986 census. Wild Cucumber is found throughout most of North America except for the far north Canadian Provinces and a few states in SE U.S. along with California and Nevada. In Minnesota is has been found throughout the state with the most absences (18 counties) in the western half. Wild Cucumber and Bur Cucumber (mentioned above) are the only two representatives of the Cucurbitaceae family found in Minnesota. There are no literature references as to the use of the plant for either food or medicinal uses.
Eloise Butler wrote of this plant: "Of the annual vines, none has a more graceful and riotous growth than the common Wild Cucumber (Echinocystis lobata). Lacking an upstanding object to embrace, it will run along the ground and form borders of bewitching spires of bloom. The fibrous, netted inside of the seed vessel, sometimes called balsam apple, resembles on a smaller scale that of a vine of the South known as the towel gourd, which is sold in the market as a bath sponge."
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"