Combretum


Combretum, the bushwillows or combretums, make up the type genus of the family Combretaceae. The genus comprises about 370 species of trees and shrubs, roughly 300 of which are native to tropical and southern Africa, about 5 to Madagascar, some 25 to tropical Asia and approximately 40 to tropical America. The genus is absent from Australia. Though somewhat reminiscent of willows in their habitus, they are not particularly close relatives of these.

Ecology

Bushwillow trees often are important plants in their habitat. Savannahs in Africa, in particular those growing on granitic soils, are often dominated by Combretum and its close relative Terminalia. For example, C. apiculatum is a notable tree in the Angolan mopane woodlands ecoregion in the Kunene River basin in southern Africa.
Other species of this genus are a major component of Southwestern Amazonian moist forests. This genus contains several species that are pollinated by mammals other than bats, which is quite rare indeed. But most species are more conventionally pollinated by insects or birds.
Typhlodromus combretum, a mite of the family Phytoseiidae, was discovered on a bushwillow plant and is named after this genus. Other herbivores that eat Combretum foliage include the caterpillars of the Brown Awl which is found on C. albidum, C. latifolium and C. ovalifolium; those of the Orange-tailed Awl are recorded from C. extensum and C. latifolium.

Use by humans

Several species are used in African or Indian herbal medicine. The class of chemical compounds known as combretastatins were first isolated from South African Bushwillow, from which they get their name. One synthetic derivative, fosbretabulin disodium, underwent preliminary study for the treatment of anaplastic thyroid cancer, but it was not effective enough to progress to more advanced trials. C. molle is also recorded to contain antioxidants such as punicalagin, which is also found in pomegranates, a somewhat related plant.
The botanist George Don studied this genus extensively. The Luvuvhu River in southern Africa was named after the river's bushwillows, locally known as muvuvhu.

Selected species


  • Combretum aculeatum
  • Combretum albidum
  • Combretum albopunctatum Suesseng.
  • Combretum apiculatum Sond.
  • * Combretum apiculatum ssp. apiculatum
  • * Combretum apiculatum var. leutweinii Exell
  • Combretum bracteosum Brandis
  • Combretum caffrum - South African bushwillow
  • Combretum celastroides Welw. ex Laws.
  • Combretum coccineum
  • Combretum collinum Fresen.
  • * Combretum collinum ssp. gazense Okafor
  • * Combretum collinum ssp. ondongense Okafor
  • * Combretum collinum ssp. suluense Okafor
  • * Combretum collinum ssp. taborense Okafor
  • Combretum comosum
  • Combretum constrictum M.A.Lawson
  • Combretum decandrum
  • Combretum dolchipeles
  • Combretum echirense Jongkind
  • Combretum edwardsii - Forest climbing bushwillow, Natal combretum
  • Combretum elaeagnoides Klotzsch
  • Combretum engleri Schinz
  • Combretum erythrophyllum Sond. - River bushwillow, muvuvhu
  • Combretum extensum
  • Combretum flagrocarpum
  • Combretum flavovirens is now Prunus dolichobotrys
  • Combretum fragrans F.Hoffm.
  • Combretum fruticosum Stuntz, type species
  • Combretum ghasalense
  • Combretum glutinosum Perr. ex DC.
  • Combretum grandiflorum
  • Combretum gueinzii Sond.
  • Combretum hereroense Schinz
  • Combretum holstii Engl.
  • Combretum imberbe - Leadwood tree
  • Combretum indicum
  • Combretum kraussii Hochst.
  • Combretum latifolium
  • Combretum lanceolatum Pohl.
  • Combretum laxum
  • Combretum leprosum Mart.
  • Combretum llewelynii
  • Combretum micranthum - Kinkeliba
  • Combretum microphyllum
  • Combretum mkuzense J.D.Carr & Retief
  • Combretum moggii Exell
  • Combretum molle R.Br. ex G.Don
  • Combretum monetaria Mart.
  • Combretum mossambicense
  • Combretum nelsonii Duemmer
  • Combretum obovatum F.Hoffm.
  • Combretum ovalifolium
  • Combretum padoides - Thicket bushwillow
  • Combretum paniculatum Vent.
  • Combretum petrophilum Retief
  • Combretum pisoniiflorum Engl.
  • Combretum platypterum
  • Combretum psidioides Welw.
  • * Combretum psidioides ssp. dinteri Engl.
  • * Combretum psidioides ssp. psidioides
  • Combretum quadrangulare
  • Combretum racemosum
  • Combretum rotundifolium Rich.
  • Combretum rupicola
  • Combretum schumannii Engl.
  • Combretum trifoliatum
  • Combretum vendae Van Wyk
  • Combretum wattii Exell
  • Combretum woodii Duemmer
  • Combretum zeyheri Sond.