Tall Morningglory (Ipomoea purpurea )
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Tall morningglory is a summer annual broadleaf vine. In California, it is found in the Central Valley, Sierra Nevada foothills, central-western region, and southwest region, to about 330 feet (100 m). Tall morningglory inhabits agricultural land and other disturbed sites. It grows best in moist places and does not tolerate freezing conditions. Morningglories are often cultivated as ornamentals, however, under favorable conditions can become problematic, especially in cotton fields. It is critical to destroy morningglories at the seedling stage. This will prevent them from twining up the stems of host plants, at which point they are difficult to control without injuring the crop. Buried seeds are viable for long periods. Ipomea species’ seeds contain many alkaloid compounds, some of which act as neurotoxins, harming humans and animals when consumed. Fortunately, contaminated forage grains do not contain enough seed to cause harm to livestock.
Agronomic and vegetable crop fields, gardens, orchards, vineyards, landscaped areas, and other disturbed, unmanaged sites.
Seeds usually germinate when moisture conditions are favorable. Cotyledons (seed leaves) are butterfly shaped, with a two-lobed tip. They are nearly equal in length and width, hairless, somewhat glossy, and are dotted on their upper surface with glands. Leaf bases are squared to somewhat rounded. The cotyledon stalk is usually purplish-red at the base. First true leaves are heart shaped with deep lobes at the base. Tall morningglory cotyledons are much larger than those of field bindweed, Convolvulus arvensis. Tall morningglory has minute hairs that usually lie flat and are more or less evenly distributed on the leaf surface, whereas a similar plant, Japanese morningglory, I. nil var. integriuscula, has erect to somewhat erect hairs on the stems, leaf stalks and veins.
Mature tall morningglory is a vine with long stems that branch, twine, and climb. Leaves are often heart shaped, sometimes three-lobed (both leaf types can occur on the same plant), and mostly range from 3 to 5 inches (7–12 cm) long. Leaves are alternate to one another along the stem. Minute flattened hairs usually cover the leaf surface, but sometimes leaves are nearly hairless. Japanese morningglory is similar in appearance but instead of flattened hairs, has erect to ascending hairs on the leaf surface.
Flowers bloom from June to November. They grow singly or in clusters of two to five showy, funnel-shaped, stalked, purple, blue, pink, white or bi-colored flowers.
Fruits consist of roundish pods, approximately 2/5 of an inch (1 cm) in diameter.
Seeds are shaped like a wedge cut out of a sphere, are dark brown to black, less than 2/5 to 1/5 of an inch (4-6 mm) long, dull, and have a granular surface. They germinate at a depth of 4 inches (10 cm) or more, much deeper than most annuals.
Reproduces by seed.
Related or similar plants
- Japanese morningglory, Ipomoea nil var. integriuscula (also called Ipomoea hederacea var. integriuscula)
- Morningglories, Convolvulus arvensis
- Field bindweed, Ipomoea spp.