Morning Glory (Ipomoea spp.) is a genus of common garden plants, recognized for its vibrant, trumpet-shaped flowers and vigorous, twining growth. These fast-growing annuals and perennials are popular for quickly covering trellises, fences, or arbors. For both gardeners cultivating this vine and those attempting to manage it as a weed, recognizing the plant in its earliest stages is important. Identifying the seedling, before the characteristic flowers appear, relies on the shape and texture of its developing leaves.
The Initial Sprout: Cotyledon Appearance
The first leaves to emerge from the soil are known as cotyledons or seed leaves. These initial structures look nothing like the mature leaves and are a frequent source of confusion. Across most common species, the cotyledons are hairless, thick, and deep green, positioned symmetrically on the stem.
A defining characteristic is their “butterfly” or two-lobed shape, often notched at the tip, forming two rounded lobes that join at the base. For species like Tall Morning Glory (Ipomoea purpurea), these cotyledons often fit within a square outline, measuring approximately 0.6 to 1 inch in length and width. The stalk supporting the cotyledons, the hypocotyl, may exhibit a purplish-red tint near the base.
The Defining Stage: Developing True Leaves
After the cotyledons have fully expanded, the first true leaves begin to emerge. This stage makes the sprout more easily recognizable, as these leaves possess the characteristic shape of the mature plant. For most common varieties, the first true leaves are distinctively heart-shaped, scientifically known as cordate.
The heart-shaped true leaf features deep lobes at the base where the stem attaches, tapering to a pointed or blunt tip. Texture is a useful identifier; the leaves and stems of many species, such as Tall Morning Glory, are covered in small hairs. Other varieties, like Ivyleaf Morning Glory (Ipomoea hederacea), develop three-lobed leaves that resemble ivy after the first unlobed true leaf emerges.
Distinguishing Morning Glory from Common Look-Alikes
Identifying Morning Glory sprouts is complicated by similar-looking vining weeds, particularly Field Bindweed (Convolvulus arvensis). Both plants belong to the same family, Convolvulaceae, and share a twining habit, but their seedling leaves offer distinctions. Morning Glory cotyledons are substantially larger than those of Field Bindweed, which tend to be more box-shaped with a slight indentation at the tip.
The shape of the true leaves is the most reliable differentiator. Morning Glory leaves are distinctly heart-shaped, while Field Bindweed leaves are narrower and shaped more like an arrowhead, with pointed basal lobes. Many Morning Glory species exhibit small hairs on their stems and leaves, while Field Bindweed stems are smoother. Morning Glory varieties are annuals, completing their life cycle in one season, whereas Field Bindweed is a perennial with a deep, aggressive root system.
Important Safety Considerations
While Morning Glory is widely cultivated, be aware of the toxicity associated with its seeds. The seeds of several species, notably Ipomoea tricolor, contain naturally occurring psychoactive compounds called lysergic acid amide (LSA), which is chemically related to LSD. Ingesting these seeds can lead to unpleasant symptoms, including nausea, vomiting, diarrhea, muscle tightness, and potential hallucinations.
The toxicity level is considered low, but the seeds should be kept strictly out of reach of children and pets. These seeds are sometimes coated with fungicides, which adds another layer of danger if consumed. Treat all parts of the plant, especially the seeds, as non-edible and handle them with caution.