Vine Weeds of Missouri - Page 11
There are at least five species of annual morningglories known to occur in Missouri, and three are considered regular pests. Bigroot is the only perennial.
The three annual morningglory species that cause economic loss are:
The cotyledons of ivyleaf and entireleaf are butterfly-shaped and essentially identical. The cotyledons of pitted are cut more deeply, a 90-degree angle, and tips are pointed, not round. Leaves on all morningglories are alternate along the stems, but leafshape is variable. Pitted and entireleaf leaves are heart-shaped; however, the leaves of pitted come to a tapering point and often have a tinge of purple around their margins, whereas entireleaf leaves are more rounded and lack the purple color. Ivyleaf leaves are densely hairy and have the English-ivy shape. All morningglories have funnel-shaped flowers, but colors vary. Pitted has white flowers. Ivyleaf and entireleaf usually have pale blue flowers.