Convolvulaceae

Lore & Background

Convolvulaceae can be recognized by their funnel-shaped, radially symmetrical corolla; the floral formula includes five sepals, five fused petals, five epipetalous stamens, and a two-part syncarpous and superior gynoecium. The stems are usually winding, hence the Latin name from convolvere, 'to wind.' Leaves are simple and alternate, without stipules; in parasitic Cuscuta (dodder) they are reduced to scales. The fruit can be a capsule, berry, or nut, each containing only two seeds per locule.

The leaves and starchy, tuberous roots of some species are used as foodstuffs, such as sweet potato and water spinach. Seeds are exploited for their medicinal value as purgatives. Some species contain ergoline alkaloids, likely responsible for their use as ingredients in psychedelic drugs (e.g., ololiuhqui). The presence of ergolines in some species is due to infection by fungi related to ergot fungi of the genus Claviceps. A study of Ipomoea asarifolia and its associated fungi showed a fungus closely related to Clavicipitaceae was always associated with ergoline alkaloids; the fungus appears to be a seed-transmitted, obligate biotroph growing epiphytically. Loline alkaloids, commonly produced by some clavicipitaceous fungi, have also been identified in a convolvulaceous species, but their origin in that species is unknown.

Members of the family are well known as food plants (sweet potatoes, water spinach), as showy garden plants (morning glory), and as troublesome weeds (bindweed, mainly Convolvulus and Calystegia, and dodder). Humbertia madagascariensis is a medium-sized tree, and Ipomoea carnea is an erect shrub. Some parasitic members are also used medicinally.

Reader's Guide

Convolvulaceae holds significance as a plant family that spans food security, horticulture, and pharmacology. Its most economically important member is the sweet potato, a staple food crop with edible tubers. Water spinach is another food species. The family also includes ornamental morning glories, widely cultivated for their showy flowers, and troublesome weeds such as bindweed and dodder, which impact agriculture. Medicinally, seeds of some species have been used as purgatives, and the presence of ergoline alkaloids—linked to symbiotic fungi—has led to their historical use in psychedelic preparations like ololiuhqui. Research indicates that these alkaloids arise from a seed-transmitted, epiphytic fungus related to Clavicipitaceae, not from the plant itself. Loline alkaloids, typically produced by clavicipitaceous fungi, have also been found in one convolvulaceous species, though their origin remains unknown. The family thus illustrates complex plant–fungus interactions that produce bioactive compounds, and its members range from parasitic vines to trees and shrubs, demonstrating diverse growth forms within a single taxonomic group.

Did You Know?

• The family name Convolvulaceae comes from the Latin convolvere, meaning 'to wind,' referring to the winding stems.
• The sweet potato is the best-known edible tuber from this family.
• Ergoline alkaloids in some Convolvulaceae species are due to symbiosis with clavicipitaceous fungi, not the plant itself.
• The parasitic genus Cuscuta (dodder) has leaves reduced to scales.