Didiereaceae is a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s found in continental

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

and

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

. It contains 20 species classified in three subfamilies and six genera. Species of the family are

succulent plant In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...

s, growing in sub-arid to arid habitats. Several are known as

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

s in specialist succulent collections. The subfamily Didiereoideae is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the southwest of Madagascar, where the species are characteristic elements of the spiny thickets.

Systematics

The family was long considered entirely endemic to Madagascar until the genera ''Calyptrotheca'', ''

Ceraria ''Portulacaria'' is a genus of succulent plant, classified in its own subfamily Portulacarioideae in the family Didiereaceae. It is indigenous to southern Africa. Taxonomy The genus was previously placed in the family Portulacaceae, but accordi ...

'', and ''

Portulacaria ''Portulacaria'' is a genus of succulent plant, classified in its own subfamily Portulacarioideae in the family Didiereaceae. It is indigenous to southern Africa. Taxonomy The genus was previously placed in the family Portulacaceae, but accordi ...

'' from the African mainland were included.

Molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

analysis confirmed the

monophyly In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...

of the family and its three subfamilies: The family is closely related to the

New World The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. 3 ...

family

Cactaceae A cactus (, or less commonly, 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 ...

(cacti), sufficiently closely so that species of Didiereaceae can be

grafted Grafting or graftage is a horticultural technique whereby tissues of plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion () while the lower part is called the rootstock. The succ ...

successfully on some cacti.

Calyptrothecoideae

Contains only one genus, ''

Calyptrotheca ''Calyptrotheca'' is a genus of flowering plants belonging to the family Didiereaceae Didiereaceae is a family of flowering plants found in continental Africa and Madagascar. It contains 20 species classified in three subfamilies and six gener ...

'', with two species found in tropical

East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historical ...

Didiereoideae

This subfamily is endemic to Madagascar, where it is found in the spiny thickets of the dry southwest. The plants are spiny

succulent In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

s and

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

s from 2–20 m tall, with thick water-storing stems and

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

that are

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

in the long

dry season The dry season is a yearly period of low rainfall, especially in the tropics. The weather in the tropics is dominated by the tropical rain belt, which moves from the northern to the southern tropics and back over the course of the year. The te ...

. 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.Rauh, W. 1983. The morphology and systematic position of the Didiereaceae of Madagascar. Bothalia 14(3/4): 839–843. All species are

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...

(''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

areole In botany, areoles are small light- to dark-colored bumps on cacti out of which grow clusters of spines. Areoles are important diagnostic features of cacti, and identify them as a family distinct from other succulent plants. Gordon Rowley - W ...

s found in

cacti A cactus (, or less commonly, 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 ...

). The flowers are unisexual (except from ''Decarya'') and radially symmetric, made up of four

tepals A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

with two basal bracts. Flowers rarely occur singly. They usually develop in branched clusters that emerge instead of leaves from the brachyblasts. There are four genera with eleven species: ''

Alluaudia ''Alluaudia'' is a genus of flowering plants in the family Didiereaceae. There are six species, all endemic to Madagascar. Most occur in the southwestern subarid forest-thicket vegetation of the island. Species of ''Alluaudia'' are dioecious, ...

'' *''

Alluaudia ascendens ''Alluaudia ascendens'' is a species of ''Alluaudia'' endemic to Madagascar.''Alluaudia''.
Madag ...

'' *''

Alluaudia comosa ''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.Rauh, W. 1983. The morphology and systematic position of the Didie ...

'' *''

Alluaudia dumosa ''Alluaudia'' is a genus of flowering plants in the family Didiereaceae. There are six species, all endemic to Madagascar. Most occur in the southwestern subarid forest-thicket vegetation of the island. Species of ''Alluaudia'' are dioecious, ...

'' *''

Alluaudia humbertii ''Alluaudia'' is a genus of flowering plants in the family Didiereaceae. There are six species, all endemic to Madagascar. Most occur in the southwestern subarid forest-thicket vegetation of the island. Species of ''Alluaudia'' are dioecious, ...

'' *''

Alluaudia montagnacii ''Alluaudia montagnacii'' is a rare species of flowering plants belonging to the family Didiereaceae. Description ''Alluaudia montagnacii'' can reach a height of . The tall columnar central trunk sprouts strong vertical branches. Stem and bran ...

'' – probably a natural hybrid of ''A. ascendens'' and ''A. procera'' *''

Alluaudia procera ''Alluaudia procera'', or Madagascar ocotillo, is a deciduous succulent plant species of the family Didiereaceae. It is endemic to south Madagascar. Description This plant is a spiny succulent shrub, with thick water-storing stems and leaves th ...

'' – quite easy grown and the most frequent species in cultivation ''

Alluaudiopsis ''Alluaudiopsis'' is a genus of shrubby flowering plants belonging to the family Didiereaceae Didiereaceae is a family of flowering plants found in continental Africa and Madagascar. It contains 20 species classified in three subfamilies and s ...

'' *'' Alluaudiopsis fiherensis'' *'' Alluaudiopsis marnieriana'' ''

Decarya ''Decarya'' is a monotypic genus of flowering plants belonging to the family Didiereaceae. It has one species ''Decarya madagascariensis'' Choux Its native range is Madagascar, and it was first described and published in Mém. Acad. Natl. Sci. L ...

'' *'' Decarya madagascariensis'' ''

Didierea ''Didierea'' is a genus of succulent flowering plants in the family Didiereaceae. It is dedicated to naturalist Alfred Grandidier (1836-1921). Species of ''Didierea'' are dioecious, with male and female flowers on separate plants. The two kn ...

'' *''

Didierea madagascariensis ''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 ...

'' *''

Didierea trollii ''Didierea'' is a genus of succulent flowering plants in the family Didiereaceae. It is dedicated to naturalist Alfred Grandidier (1836-1921). Species of ''Didierea'' are dioecious, with male and female flowers on separate plants. The two kn ...

'' Key to the genera of Didieroideae:

Portulacarioideae

Contains one genus, ''

'', with seven species, distributed in

Southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number of ...

. Species formerly considered in the separate genus ''

'' are now included in ''Portulacaria''.

Gallery

File:Ceraria_namaquensis_01_ies.jpg, '' Portulacaria namaquensis'' File:Jade_leaves.jpg, ''

Portulacaria afra ''Portulacaria afra'' (known as elephant bush, porkbush, purslane tree and ' in Afrikaans) is a small-leaved succulent plant found in South Africa. These succulents commonly have a reddish stem and leaves that are green, but also a variegated ...

'' File:Alluaudia ascendens.JPG, ''Alluaudia ascendens'' File:Alluadia comosa Tsimanampetsotsa.jpg, ''Alluaudia comosa'' File:Alluaudia montagnacii.jpg, ''Alluaudia montagnacii'' File:Alluaudia procera2.JPG, ''Alluaudia procera''

References

{{Taxonbar, from=Q131286 Caryophyllales families Desert flora Flora of Africa