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Statewide IPM Program, University of California

Japanese Morningglory  (Ipomoea nil var. integriuscula also called Ipomoea hederacea var. integriuscula)

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Life stages of Japanese Morningglories mature plant with lobed leaves mature plant with unlobed leaves flower seedling seed

Japanese morningglory is a summer annual broadleaf vine. In California it is found in the San Joaquin Valley and southwestern region of California to about 800 feet (250 m). Japanese morningglory grows best in moist places and does not tolerate freezing conditions. Morningglories are often cultivated as ornamentals, however, under favorable conditions they can become problematic weeds, especially in cotton fields. Control is critical from crop emergence to harvest. Destroy morningglories at the seedling stage, because once they have twined up stems they are difficult to control without injuring the crop. When buried in the soil, seeds survive for long periods. Seeds of Ipomoea species contain many alkaloid compounds, some of which are neurotoxins when ingested by humans and animals. Fortunately, there is not enough seed in contaminated grain to cause harm to livestock.

Habitat

Agronomic and vegetable crop fields, gardens, orchards, vineyards, landscaped areas, and disturbed, unmanaged sites.

Seedling

Seedlings emerge typically when moisture conditions are favorable. The cotyledons (seed leaves) are butterfly-shaped, hairless, and somewhat glossy, with nearly equal width and length. It is more deeply notched and much larger than field bindweed, Convolvulus arvensis, cotyledons. The cotyledon stalk is long and usually purplish red at the base. First true leaves are heart-shaped with deep lobes at the base. Japanese morningglory has erect to somewhat erect hairs on the stems, leaf stalks, and veins, whereas, tall morningglory, Ipomoea purpurea, a similar species, has minute hairs that usually lie flat and are more or less evenly distributed on the leaf surface.

Mature plant

Long stems branch, twine, and climb. Leaves, most often are 1-1/5 to 3 inches (3 to 8 cm) long, heart shaped and/or three lobed. They are alternate to one another along the stem. Short stiff hairs cover the plant surface, especially on the stems and stalks. Leaves are more or less sparsely hairy, with most hairs on the leaf veins.

Flowers

Flowers bloom from June to November. They are showy, funnel-shaped, stalked, and usually pale blue to purple, single, or in a cluster of two to three.

Fruits

Fruits consist of roundish pods, approximately 2/5 of an inch (1 cm) in diameter.

Seed

Seeds are shaped like a wedge cut out of a sphere, are dark brown to black, less than about 2/5 to 1/5 of an inch (4-6 mm) long, dull, and have a granular surface. They germinate down to a depth of 4 inches (10 cm) or more, much deeper than most annuals.

Reproduction

Reproduces by seed.

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