Dalechampia is a genus of flowering plants in the family Euphorbiaceae, order Malpighiales, and the sole member of the monogeneric subtribe Dalechampiinae. The genus comprises roughly 120 species of vines, shrubs, and herbs distributed across lowland tropical regions of the world, generally below 2,000 metres elevation, with the greatest diversity in the Americas and smaller contingents in Africa, Madagascar, and southern Asia. New species continue to be described, and several are rare and at risk of extinction.
A defining characteristic of Dalechampia is its elaborate blossom structure. Individual flowers are unisexual, but they are secondarily grouped into bisexual pseudanthia — composite false blossoms — that function as the plant's effective pollination unit. The pollination biology and floral evolution of Dalechampia have been studied more intensively than perhaps any other genus in the euphorbia family. In the neotropics, most species are serviced by resin-collecting female bees, including euglossine bees and members of Hypanthidium (Megachilidae), which harvest resin for nest construction. About a dozen neotropical species are instead pollinated by fragrance-collecting male euglossine bees, which use floral scents to attract mates. At least three independent evolutionary shifts from resin-based to fragrance-based pollination have been documented within the genus. In Africa and Asia, resin-collecting megachilid bees are also the primary pollinators, while in Madagascar the role is taken by pollen-feeding beetles and pollen-collecting bees.
Two species have attracted particular horticultural interest: Dalechampia spathulata and Dalechampia aristolochiifolia, both of which bear exceptionally showy blossoms framed by bright pink or purple bracts. Dalechampia aristolochiifolia, native to Peru, has become popular in cultivation but is frequently misidentified and sold under the name Dalechampia dioscoreifolia.
Distribution
Dalechampia is widespread across lowland tropical regions of the world, generally below 2,000 metres above sea level. The genus reaches its greatest diversity in the Americas (the neotropics), with additional species in Africa, Madagascar, and southern Asia.
Ecology
Pollination systems within Dalechampia are unusually diverse and well-studied. Neotropical species are predominantly pollinated by resin-collecting female bees (euglossines and Hypanthidium/Megachilidae), which gather resin for nest building. Roughly a dozen neotropical species have shifted to fragrance-collecting male euglossine bees as pollinators, with at least three independent evolutionary transitions documented. In Africa and Asia, resin-collecting megachilid bees fill the same role, while Malagasy species are pollinated by pollen-feeding beetles and pollen-collecting bees.
Taxonomy Notes
Dalechampia is placed in the monogeneric subtribe Dalechampiinae within the family Euphorbiaceae. In the GBIF backbone taxonomy it sits in order Malpighiales, class Magnoliopsida. Additional new species are still being described from the tropics, making the exact species count provisional.
