Convolvulaceae

Lore & Background

Convolvulaceae can be recognized by their funnel-shaped, radially symmetrical corolla; the floral formula for the family has five sepals, five fused petals, five epipetalous stamens, and a two-part syncarpous and superior gynoecium. The stems are usually winding, hence their 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, and seeds are exploited for medicinal value as purgatives. Some species contain ergoline alkaloids, likely responsible for their use as ingredients in psychedelic drugs like ololiuhqui. The presence of ergolines is due to infection by fungi related to ergot fungi of the genus Claviceps. A study of Ipomoea asarifolia showed a fungus closely related to Clavicipitaceae was always associated with ergoline alkaloids, suggesting symbiosis with clavicipitaceous fungi. Loline alkaloids, commonly produced by some clavicipitaceous fungi, have also been identified in a convolvulaceous species, though their origin is unknown.

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

Reader's Guide

Convolvulaceae holds significance as a diverse plant family that includes staple food crops, ornamental species, and problematic weeds. The sweet potato, a tuberous root of this family, is a major food source worldwide. The family also includes water spinach, a leafy vegetable. Garden morning glories are widely cultivated for their showy flowers. Conversely, bindweeds and dodder are notorious agricultural weeds. The family is notable for the presence of ergoline alkaloids in some species, which have been used in traditional psychedelic preparations such as ololiuhqui. Research indicates that these alkaloids arise from a symbiotic relationship with clavicipitaceous fungi, rather than being produced by the plant itself. This finding clarifies the unique distribution of such compounds within the family. The discovery of loline alkaloids in a convolvulaceous species, though of unknown origin, further links the family to fungal symbionts. The family's economic impact spans food production, horticulture, and weed management, while its chemical ecology offers insights into plant-fungal interactions.

Did You Know?

• The family includes about 60 genera and more than 1,650 species.
• The sweet potato is the best-known edible tuber from this family.
• Some species contain ergoline alkaloids due to symbiosis with clavicipitaceous fungi.
• The stems are usually winding, giving the family its name from the Latin 'convolvere,' meaning 'to wind.'

Taxonomic Controversy

The classification of the common woolly monkey remains one of the more contentious issues in primate systematics. Fooden originally organized the genus Lagothrix around two species, placing four subspecies under L. lagothricha. Subsequent craniodental studies proposed elevating all four to full species status and simultaneously reassigning the yellow-tailed woolly monkey into its own monotypic genus, Oreonax. Molecular analyses added another layer of complexity, identifying distinct genetic clusters that do not always align with morphological groupings. A 2014 study ultimately settled on two species—L. lagothrica and L. flavicauda—with five subspecies under the former, a framework now endorsed by the American Society of Mammalogists and the IUCN Red List. The five recognized subspecies include the gray (L. l. cana), brown (L. l. lagothrica, the type), Colombian (L. l. lugens), silvery (L. l. poeppigii), and Peruvian (L. l. tschudii) woolly monkeys. Even the spelling of the specific name remains debated, with many sources using "lagothricha" following Fooden's revision, though Humboldt's original description employed both variants.

Physical Form & Daily Rhythm

Common woolly monkeys rank among the larger arboreal primates, with head-and-body lengths spanning 40 to 60 centimeters and tails stretching 55 to 75 centimeters. Adults weigh between 5.5 and 10.8 kilograms. Despite the "brown" in their common name, their pelage can appear grey or black, with darker tones on the head and underparts. The face is entirely bare and typically black. Males consistently outweigh females and bear noticeably larger canines. These monkeys are diurnal, active during daylight hours. They inhabit the upper Amazon basin, ranging from the Rio Tapajos in Brazil across eastern Peru, Ecuador, and Colombia, with scattered populations reaching north into Venezuela. Historically they also occupied parts of Bolivia, though hunting has likely eliminated them from that country. Their preferred habitat is the rainforest canopy of the tallest trees, though they occasionally descend to the shrub layer, and in certain seasons groups venture into flooded forests where berry concentrations are higher.

Feeding Ecology & Seed Dispersal

Although classified as omnivores, common woolly monkeys are predominantly frugivorous, favoring fruits with one or two large seeds that are relatively low in fat but rich in sugar and water. Fruits from the Fabaceae, Moraceae, Convolvulaceae, and Sapotaceae families account for roughly half of their feeding time. However, abundance and seasonal production outweigh strict preference; when fruit becomes scarce, the monkeys shift toward leaves and insects. Females carrying dependents consume more foliage, likely to access the extra protein needed for milk production, while juveniles eat proportionally more arthropods. Their foraging is generalist and opportunistic, covering approximately two kilometers daily. They favor fruit species with clumped distributions on large trees to minimize travel energy. Females with offspring forage more efficiently than juveniles or adult males, and inter-group competition during feeding displaces younger individuals toward less preferred food items. As seed dispersers, woolly monkeys outperform the morphologically similar spider monkey, retaining seeds longer in their digestive tracts and consuming a wider variety of seed types.

Social Dynamics & Conservation Outlook

Woolly monkeys live in groups ranging from two to seventy individuals, typically fragmenting into smaller subgroups during active periods. Within these communities, females drive the social architecture of cross-sex relationships. They do not mingle with other females, while males interact with both sexes. Females are possessive of males and may harass rivals attempting to engage them, yet they remain accepting of outsiders when no offspring-producing females are present. The species is classified as vulnerable by the IUCN, despite occupying a broader range than the yellow-tailed woolly monkey. The principal threat is human activity: highway construction through the Amazon accelerates deforestation and opens previously inaccessible forest to hunters, primarily indigenous communities. The monkeys' large size makes them attractive targets, and individuals are sometimes sold locally as pets. After mothers are killed, infants can fetch around eighty US dollars. Populations continue to decline, and the species occurs both within and outside legally protected areas.

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