The island of Madagascar sits roughly 1000 miles off the southeastern coast of Africa, and is home to over 10,000 plant species, most of which are found nowhere else on earth. Many of these plant species reside within Madagascar’s “spiny forest”, an ecoregion on the southwestern corner of the island, known for its nutrient-poor soil and erratic winter rainfall.  The harsh conditions lead to highly adaptive plant species that often exhibit amazing examples of Convergent Evolution.

Ninety per cent of Malagasy wildlife is endemic to the island.  Madagascar split from the Gondwanan Africa-South America landmass 135 million years ago, and further separated from India 88 million years ago.  This acounts for Madagascar high levels of endemism, as most species have been virtually isolated for the past 88 million years.

Here are some of Duke’s Madagascar species:

Didiereaceae

Didiereaceae is a small family of succulent plants with just four genera and 11 species. Its plants are covered in protective spines and represent a conspicuous component of Madagascar’s spiny forests.  All species within this family are dioecious plants—plants that are either male or female.  The leaves often appear singular or in paired groups and grow directly from the trunk and branches. 

    • Didiereaceae
    • Alluaudia procera

    • Photo Credit: Jacob Golan
    • Didiereaceae
    • Alluaudia adscendens

    • Photo Credit: Jacob Golan
    • Didiereaceae
    • Didierea madagascarensis

    • Photo Credit: Jacob Golan
    • Didiereaceae
    • Alluaudia dumosa

    • Photo Credit: Jacob Golan
    • Didiereaceae
    • Alluadia dumosa

    • Photo Credit: Jenny Gordon
    • Didiereaceae
    • Alluandianopsis fiherensis

    • Photo Credit: Jenny Gordon
    • Didiereaceae
    • Didierea trollii

    • Photo Credit: Jenny Gordon
    • Didiereaceae
    • Alluadia adscendens

    • Photo Credit: Jenny Gordon
    • Didiereaceae
    • Alluadia adscendens

    • Photo Credit: Jenny Gordon
    • Didiereaceae
    • Didierea madagascariensis

    • Photo Credit: Jenny Gordon
    • Didiereaceae
    • Alluaudia adscendens

    • Photo Credit: Jenny Gordon
    • Didiereaceae
    • Didierea madagascariensis

    • Photo Credit: Jenny Gordon
    • Didiereaceae
    • Alluadia comosa

    • Photo Credit: Jenny Gordon
    • Didiereaceae
    • Alluadia comosa

    • Photo Credit: Jenny Gordon
    • Didiereaceae
    • Alluadianopsis fiherensis

    • Photo Credit: Jenny Gordon
  • Previous
  • Next

Pachypodium (Apocynaceae)

Pachypodium is a succulent, spine-bearing genus coming from the Latin words meaning ‘thick-footed’. The name derives from its swollen trunk—perfect for storing water in xeric climates. Spines, which grow in groups of twos and threes, emerge with leaves, but do not regenerate and gradually wear.  Depending on the specific location of and localized stresses to the plant, branching may occur at either the top or bottom of the trunk. Of the 25 known species of Pachypodium, 20 are native to Madagascar, though others appear nearby in southern Africa. 

    • Apocynaceae
    • Pachypodium lamerei

    • Photo Credit: Jenny Gordon
    • Apocynaceae
    • Pachypodium lamerei

    • Photo Credit: Jacob Golan
    • Apocynaceae
    • Pachypodium geayi

    • Photo Credit: Jenny Gordon
    • Apocynaceae
    •  Pachypodium lealii

    • Photo Credit: Jenny Gordon
  • Previous
  • Next

Euphorbia intisy (Euphorbiaceae)

Though part of Euphorbiaceae, this plant is unique in that it is both shrub and succulent. Milky sap from this latex-bearing plant can be used as a rubber source. 

    • Euphorbiaceae
    • Euphorbia intisy

    • Photo Credit: Jacob Golan

Kalanchoe beharensis (Crassulaceae)

Also known as Elephant’s Ear Kalanchoe, Kalanchoe beharensis is a succulent plant, covered in a fine woolly hair, unlike most members of “Madagascar’s spiny forest”. The plant has an unusual defense system: when under stress from herbivores, the plant will initiate a crack in its leaves and rapidly begin to harden and break apart.  This defense is effective in warding off herbivores due to the unpalatable nature of the fragmented leaves. 

    • Crassulaceae
    • Kalanchoe beharensis

    • Photo Credit: Jenny Gordon
    • Crassulaceae
    • Kalanchoe beharensis

    • Photo Credit: Jenny Gordon
  • Previous
  • Next

Adansonia (Malvaceae)

Sometimes referred to as upside-down tree, these huge trees have trunks swollen with stored water.  The small foliage cover at the trunk apex resembles an upturned root system.  These are the trees in which the lemurs of the movie “Madagascar” live, although in nature such is not the case.

    • Malvaceae
    • Adansonia digita

    • Photo Credit: Jacob Golan

Boophone disticha (Amaryllidaceae)

This tropical flowering plant endemic to Africa, and is one of the most widely spread bulbous species in the region. Due to its elongated flowering head, it is easily transported by the wind, resembling tumbleweeds in the mid-West. While the plant has been used in traditional medicine to treat pain and wounds, its bulb is also highly poisonous and was once used by Bushmen to prepare poisoned arrowheads. This plant is also know as the “sore-eye flower” as it can cause sore eyes and headaches, and contains the compound buphanine, which can cause agitation, hallucination, and coma.

    • Amaryllidaceae
    • Boophone sp.

    • Photo Credit: Jenny Gordon
    • Amaryllidaceae
    • Boophone sp.

    • Photo Credit: Jenny Gordon
  • Previous
  • Next

Page by Jacob Golan and Aziza-Mistral J. Sullivan

 
  • Equisetaceae
  • Fabaceae
  • Commeliniaceae
  • Ericaceae
  • Araceae
  • Begoniaceae
  • Araceae
  • Previous
  • Next