Didiereaceae

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Didiereaceae
Alluaudia montagnacii.jpg
Alluaudia montagnacii
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Didiereaceae
Radlk. [1]
Subfamilies

Didiereaceae is a family of flowering plants found in continental Africa and Madagascar. It contains 20 species classified in three subfamilies and six genera. Species of the family are succulent plants, growing in sub-arid to arid habitats. Several are known as ornamental plants in specialist succulent collections. The subfamily Didiereoideae is endemic to the southwest of Madagascar, where the species are characteristic elements of the spiny thickets.

Contents

Systematics

The family was long considered entirely endemic to Madagascar until the genera Calyptrotheca, Ceraria , and Portulacaria from the African mainland were included. [2] Molecular phylogenetic analysis confirmed the monophyly of the family and its three subfamilies: [3]

Didiereaceae
Portulacarioideae

Portulacaria

Calyptrothecoideae

Calyptrotheca

Didiereoideae

Alluaudiopsis

Alluaudia

Decarya

Didierea

The family is closely related to the New World family Cactaceae (cacti), sufficiently closely so that species of Didiereaceae can be grafted successfully on some cacti. [3]

Calyptrothecoideae

Contains only one genus, Calyptrotheca , with two species found in tropical East Africa. [3]

Didiereoideae

This subfamily is endemic to Madagascar, where it is found in the spiny thickets of the dry southwest. The plants are spiny succulent shrubs and trees from 2–20 m tall, with thick water-storing stems and leaves that are deciduous in the long dry season. All of the species except Alluaudiopsis have a distinct youth form. They start as small procumbent shrubs but eventually a dominant stem is produced that becomes a trunk. The trunk later branches forming a crown and the basal branches die off. [4] All species are dioecious (Decarya female-dioecious). The plants have different long-shoots and short-shoots (brachyblasts). Long-shoot leaves are soon deciduous, but brachyblasts form in the leaf axils and from them grow small leaves that appear singly or in pairs and are accompanied by conical spines (much like the areoles found in cacti). The flowers are unisexual (except from Decarya) and radially symmetric, made up of four tepals with two basal bracts. Flowers rarely occur singly. They usually develop in branched clusters that emerge instead of leaves from the brachyblasts. [4]

There are four genera with eleven species:

Alluaudia (Drake) Drake 1903

Alluaudiopsis Humbert & Choux 1934

Decarya Choux 1929

Didierea Baillon 1880

Key to the genera of Didieroideae:

1Spines in groups of four or more:Didierea
-Spines single or in pairs:→ 2
2Shoots striking zigzagged, spines short conical:Decarya
-Shoots not zigzagged, spines long conical to needle-like:→ 3
3Shrubs strongly branched, leaves lanceolate:Alluaudiopsis
-Shrubs little branched, leaves either ovate to circular or scale-like and awl-shaped:Alluaudia

Portulacarioideae

Contains one genus, Portulacaria , with seven species, distributed in Southern Africa. Species formerly considered in the separate genus Ceraria are now included in Portulacaria. [3]

Related Research Articles

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A cactus is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word cactus derives, through Latin, from the Ancient Greek word κάκτος (káktos), a name originally used by Theophrastus for a spiny plant whose identity is now not certain. Cacti occur in a wide range of shapes and sizes. They are native to the Americas, with the exception of Rhipsalis baccifera, which is also found in Africa. Cacti are adapted to live in very dry environments, including the Atacama Desert, one of the driest places on Earth. Because of this, cacti show many adaptations to conserve water. For example, almost all cacti are succulents, meaning they have thickened, fleshy parts adapted to store water. Unlike many other succulents, the stem is the only part of most cacti where this vital process takes place. Most species of cacti have lost true leaves, retaining only spines, which are highly modified leaves. As well as defending against herbivores, spines help prevent water loss by reducing air flow close to the cactus and providing some shade. In the absence of true leaves, cacti's enlarged stems carry out photosynthesis. Cacti are native to the Americas, ranging from Patagonia in the south to parts of western Canada in the north—except for Rhipsalis baccifera, which also grows in Africa and Sri Lanka.

<i>Alluaudia</i> Genus of flowering plants

Alluaudia is a genus of flowering plants in the family Didiereaceae. There are six species, all endemic to Madagascar.

<i>Alluaudia procera</i> Species of flowering plant

Alluaudia procera, or Madagascar ocotillo, is a deciduous succulent plant species of the family Didiereaceae. It is endemic to south Madagascar.

<i>Alluaudia ascendens</i> Species of flowering plant

Alluaudia ascendens is a species of Alluaudia endemic to Madagascar. It can reach 15 m in height. Its local name is fantsiolotse.

Meineckia is a genus of flowering plants in the family Phyllanthaceae first described as a genus in 1858.

<span class="mw-page-title-main">Madagascar spiny forests</span> Ecoregion in Southwest Madagascar

The Madagascar spiny forests is an ecoregion in the southwest of Madagascar. The vegetation type is found on poor substrates with low, erratic winter rainfall. The ecoregion contains an outstanding proportion of endemic plant species and is listed as one of the 200 most important ecological regions in the world; one of the Global 200.

<i>Portulacaria</i> Genus of succulents

Portulacaria is a genus of succulent plant, classified in its own subfamily Portulacarioideae in the family Didiereaceae. It is indigenous to southern Africa.

<span class="mw-page-title-main">Tsimanampetsotsa National Park</span>

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<span class="mw-page-title-main">Caryophyllales</span> Order of flowering plants

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<span class="mw-page-title-main">Succulent plant</span> Plants having some parts that are more than normally thick and fleshy

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<span class="mw-page-title-main">Emmanuel Drake del Castillo</span>

Emmanuel Drake del Castillo was a French botanist.

<i>Didierea madagascariensis</i> Species of flowering plant

Didierea madagascariensis, commonly known as the octopus tree, is a species of Didiereaceae endemic to the spiny thickets of southwestern Madagascar. It was first described scientifically by the French botanist Henri Ernest Baillon in 1880 and is the type species of the genus Didierea.

<i>Alluaudia montagnacii</i> Species of flowering plant

Alluaudia montagnacii is a rare species of flowering plants belonging to the family Didiereaceae.

Octopus tree is a common name for several plants and may refer to:

<i>Ceraria namaquensis</i> Species of succulent

Ceraria namaquensis, with the common names Namaqua porkbush and Namaqua portulacaria, is a species of succulent shrub, native to the border between South Africa and Namibia.

<i>Portulacaria pygmaea</i> Species of succulent

Portulacaria pygmaea, also known as the pygmy porkbush, is a small-leaved dwarf succulent plant found on the border between Namibia and South Africa.

<i>Portulacaria fruticulosa</i> Species of succulent

Portulacaria fruticulosa is a succulent plant found on the border between Namibia and South Africa.

<i>Didierea</i> Genus of flowering plants

Didierea is a genus of succulent flowering plants in the family Didiereaceae. It is dedicated to naturalist Alfred Grandidier (1836-1921).

<i>Alluaudia comosa</i> Species of flowering plant

Alluaudia comosa is a rare species of flowering plant. It belongs to the family Didiereaceae, subfamily Didiereoideae, which is found only in the coastal area of SW Madagascar. Didierea comosa Drake is a synonym. It is listed as "vulnerable" on the IUCN Red List of Threatened Species.

Alluaudiopsis is a genus of shrubby flowering plants belonging to the family Didiereaceae. Species of Alluaudiopsis are dioecious, with male and female flowers on separate plants.

References

  1. Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III". Botanical Journal of the Linnean Society. 161 (2): 105–121. doi: 10.1111/j.1095-8339.2009.00996.x .
  2. Applequist, Wendy L.; Wallace, Robert S. (2003). "Expanded circumscription of Didiereaceae and its division into three subfamilies" (PDF). Adansonia. 25 (1): 13–16. ISSN   1280-8571. Open Access logo PLoS transparent.svg
  3. 1 2 3 4 Bruyns, Peter V.; Oliveira-Neto, Mario; Melo-de-Pinna, Gladys Flavia; Klak, Cornelia (2014). "Phylogenetic relationships in the Didiereaceae with special reference to subfamily Portulacarioideae". Taxon. 63 (5): 1053–1064. doi:10.12705/635.36. ISSN   0040-0262.
  4. 1 2 Rauh, W. 1983. The morphology and systematic position of the Didiereaceae of Madagascar. Bothalia 14(3/4): 839–843.