Virginia Tech Weed Identification Guide

Tall Morningglory: Ipomoea purpurea

Weed Description:  A trailing or climbing annual vine with heart-shaped leaves and purple to white flowers.  Primarily a weed of agronomic crops, nurseries, landscapes and noncrop areas that is found throughout the eastern half of the United States except for the far northern states.
Seedling:  Cotyledons are only moderately indented as compared to either pitted, palmleaf, sharppod, or cotton morningglory.  Cotyledon lobes are rounded and not pointed to any degree and cotyledons are also almost perfectly square in outline.  The first true leaf is heart shaped as are all subsequent leaves, but the first true leaf often is without hairs unlike the subsequent leaves.
Leaves:  Heart-shaped in outline, arranged alternately along the stem, and have hairs that lie flat against the leaf surface (appressed).  Older leaves have rounded bases that often overlap, unlike pitted morningglory.  All leaves occur on relatively long petioles.
Stems:  Hairy, trailing or climbing, capable of reaching 6 1/2 feet in length.

Flowers:  Occur in clusters of 3 or more and may be purple to white in color, or have some traces of both colors.  Flowers range from 1 3/4 to 3 inches in length and have sepals at the base of the flower that are approximately 10 to 15 mm long.

tallmg10-7.jpg (30986 bytes) Fruit:  A brown capsule containing 4 to 6 dark brown to black seeds.
Identifying Characteristics:     The distinctive heart-shaped leaves and purple to white flowers helps to distinguish tall morningglory from most of the other morningglories.  When mature, the leaves of tall morningglory and Pitted Morningglory (Ipomoea lacunosa) are similar, however the leaf bases of tall morningglory often overlap one another and are much more heart-shaped in outline when compared to pitted morningglory.  The cotyledons of tall morningglory also resemble those of Entireleaf Morningglory (Ipomoea hederacea var. integriuscula) and Ivyleaf Morningglory (Ipomoea hederacea). However, the cotyledons of tall morningglory are usually more square in outline when compared to the cotyledons of either ivyleaf or entireleaf morningglory. tallmg10-7b.jpg (39316 bytes)