Didiereaceae
Encyclopedia
Didiereaceae is a small family
of just four genera and 11 species of flowering plant
s endemic
to south and southwest Madagascar
, where they form an important component of the Madagascar spiny forests
.
succulent
shrub
s and tree
s from 2-20 m tall, with thick water-storing stems and leaves
that are deciduous
in the long dry season
. Some species build a distinct youth form as small procumbent shrub before a dominant stem is produced.
All species are dioecious
(Decaria female-dioecious). The leaves, produced from areole
s like in cacti
, are small, appear single or in pairs and are accompanied by conical spines. The flowers are unisexual (except from Decaria) and radial symmetric.
The family is sometimes included within the Portulacaceae
, but is treated as distinct by the Angiosperm Phylogeny Group
. It is also closely related to the New World
family Cactaceae
(cacti), sufficiently closely so that the species of Didiereaceae can be grafted
successfully on some cacti.
(Drake
) Drake
1903
Alluaudiopsis Humbert & Choux 1934
Decaria Choux 1929
Didierea Baillon1880
Several of the species are grown as indoor ornamental plant
s in specialist succulent collections.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of just four genera and 11 species of flowering plant
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
s endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
to south and southwest Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
, where they form an important component of the Madagascar spiny forests
Madagascar spiny thickets
The Madagascar spiny thickets is an ecoregion in Madagascar. The vegetation type is found on poor substrates with low, erratic winter rainfall. An estimated 14,000 to is covered with this habitat, all in the southwest of the country...
.
Description
The plants are spinyThorns, spines, and prickles
In botanical morphology, thorns, spines, and prickles are hard structures with sharp, or at least pointed, ends. In spite of this common feature, they differ in their growth and development on the plant; they are modified versions of different plant organs, stems, stipules, leaf veins, or hairs...
succulent
Succulent plant
Succulent plants, also known as succulents or fat plants, are water-retaining plants adapted to arid climates or soil conditions. Succulent plants store water in their leaves, stems, and also in roots...
shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s and tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s from 2-20 m tall, with thick water-storing stems and leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
that are deciduous
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
in the long dry season
Dry season
The dry season is a term commonly used when describing the weather in the tropics. The weather in the tropics is dominated by the tropical rain belt, which oscillates from the northern to the southern tropics over the course of the year...
. Some species build a distinct youth form as small procumbent shrub before a dominant stem is produced.
All species are dioecious
Dioecious
Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...
(Decaria female-dioecious). The leaves, produced from areole
Areole
Areoles are an important diagnostic feature of cacti, and identify them as a family distinct from other succulent plants. The areoles on cacti are clearly visible; they generally appear as small light- to dark-colored bumps, out of which grow clusters of spines...
s like in cacti
Cacti
-See also:* RRDtool The underlying software upon which Cacti is built* MRTG The original Multi Router Traffic Grapher from which RRDtool was "extracted".* Munin -External links:******...
, are small, appear single or in pairs and are accompanied by conical spines. The flowers are unisexual (except from Decaria) and radial symmetric.
The family is sometimes included within the Portulacaceae
Portulacaceae
Portulacaceae are a family of flowering plants, comprising about 20 genera with about 500 species, ranging from herbaceous plants to shrubs. The family has been recognised by most taxonomists, and is also known as the purslane family; it has a cosmopolitan distribution, with the highest diversity...
, but is treated as distinct by the Angiosperm Phylogeny Group
Angiosperm Phylogeny Group
The Angiosperm Phylogeny Group, or APG, refers to an informal international group of systematic botanists who came together to try to establish a consensus on the taxonomy of flowering plants that would reflect new knowledge about plant relationships discovered through phylogenetic studies., three...
. It is also closely related to the New World
New World
The New World is one of the names used for the Western Hemisphere, specifically America and sometimes Oceania . The term originated in the late 15th century, when America had been recently discovered by European explorers, expanding the geographical horizon of the people of the European middle...
family Cactaceae
Cactus
A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...
(cacti), sufficiently closely so that the species of Didiereaceae can be grafted
Grafting
Grafting is a horticultural technique whereby tissues from one plant are inserted into those of another so that the two sets of vascular tissues may join together. This vascular joining is called inosculation...
successfully on some cacti.
Key to the genera
| 1 | Spines in groups of 4 or more: | Didierea |
| - | Spines single or in pairs: | → 2 |
| 2 | Shoots striking zigzagged, spines short conical: | Decarya |
| - | Shoots not zigzagged, spines long conical to needle-like: | → 3 |
| 3 | Shrubs strongly branched, leaves lanceolate: | Alluaudiopsis |
| - | Shrubs little branched, leaves either ovate to circular or scale-like and awl-shaped: | Alluaudia |
Genera and species
AlluaudiaAlluaudia
Alluaudia is a genus of six species of flowering plants endemic to Madagascar, where they form an important component of the Madagascar spiny forests. They are spiny succulent shrubs and trees from 2–20 m tall, with leaves that are deciduous in the long dry season...
(Drake
Emmanuel Drake del Castillo
Emmanuel Drake del Castillo was a French botanist.He was born at Paris and studied with Louis Édouard Bureau at the Muséum national d'histoire naturelle...
) Drake
Emmanuel Drake del Castillo
Emmanuel Drake del Castillo was a French botanist.He was born at Paris and studied with Louis Édouard Bureau at the Muséum national d'histoire naturelle...
1903
- Alluaudia ascendensAlluaudia ascendensAlluaudia ascendens is a species of Alluaudia endemic to Madagascar. It can reach 15 m in height. Its local name is fantsiolotse....
(DrakeEmmanuel Drake del CastilloEmmanuel Drake del Castillo was a French botanist.He was born at Paris and studied with Louis Édouard Bureau at the Muséum national d'histoire naturelle...
) DrakeEmmanuel Drake del CastilloEmmanuel Drake del Castillo was a French botanist.He was born at Paris and studied with Louis Édouard Bureau at the Muséum national d'histoire naturelle...
1903 - Alluaudia comosa (DrakeEmmanuel Drake del CastilloEmmanuel Drake del Castillo was a French botanist.He was born at Paris and studied with Louis Édouard Bureau at the Muséum national d'histoire naturelle...
) DrakeEmmanuel Drake del CastilloEmmanuel Drake del Castillo was a French botanist.He was born at Paris and studied with Louis Édouard Bureau at the Muséum national d'histoire naturelle...
1903 - Alluaudia dumosa (DrakeEmmanuel Drake del CastilloEmmanuel Drake del Castillo was a French botanist.He was born at Paris and studied with Louis Édouard Bureau at the Muséum national d'histoire naturelle...
) DrakeEmmanuel Drake del CastilloEmmanuel Drake del Castillo was a French botanist.He was born at Paris and studied with Louis Édouard Bureau at the Muséum national d'histoire naturelle...
1903 - Alluaudia humbertii Choux 1934
- Alluaudia montagnacii RauhWerner RauhWerner Rauh was an internationally renowned German botanist and author.-Biography:Born in the town of Niemegk in Brandenburg, Rauh studied at the University of Halle under the famous morphologist Wilhelm Troll and received his doctorate in 1937 before coming to the University of Heidelberg two...
1961 – probably a natural hybrid of A. ascendens and A. procera - Alluaudia procera (DrakeEmmanuel Drake del CastilloEmmanuel Drake del Castillo was a French botanist.He was born at Paris and studied with Louis Édouard Bureau at the Muséum national d'histoire naturelle...
) DrakeEmmanuel Drake del CastilloEmmanuel Drake del Castillo was a French botanist.He was born at Paris and studied with Louis Édouard Bureau at the Muséum national d'histoire naturelle...
1903 – quite easy grown and the most frequent species in cultivation
Alluaudiopsis Humbert & Choux 1934
- Alluaudiopsis fiherensis Humbert & Choux 1934
- Alluaudiopsis marnieriana RauhWerner RauhWerner Rauh was an internationally renowned German botanist and author.-Biography:Born in the town of Niemegk in Brandenburg, Rauh studied at the University of Halle under the famous morphologist Wilhelm Troll and received his doctorate in 1937 before coming to the University of Heidelberg two...
1961
Decaria Choux 1929
- Decaria madagascariensis Choux 1929
Didierea Baillon1880
- Didierea madagascariensisDidierea madagascariensisDidierea madagascariensis, commonly known as the Octopus tree, is a species of Didiereaceae endemic to the spiny thickets of Madagascar. It was first described scientifically by the French botanist Henri Ernest Baillon in 1880. The type species of the genus Didierea, it is a densely spiny succulent...
BaillonHenri Ernest BaillonHenri Ernest Baillon was a French botanist and physician. He was born in Calais on November 30, 1827 and died in Paris on July 19, 1895.Baillon spent his professional life as a professor of natural history, and he published numerous works on botany...
1880 - Didierea trollii CapuronRené Paul Raymond CapuronRené Paul Raymond Capuron was a French botanist. Capuron was responsible for an extensive amount of work on the tree flora of Madagascar.- Works :Highlights of his work include:* M...
& RauhWerner RauhWerner Rauh was an internationally renowned German botanist and author.-Biography:Born in the town of Niemegk in Brandenburg, Rauh studied at the University of Halle under the famous morphologist Wilhelm Troll and received his doctorate in 1937 before coming to the University of Heidelberg two...
1961
Several of the species are grown as indoor ornamental plant
Ornamental plant
Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...
s in specialist succulent collections.
Literature
- Eggli, Urs (Ed.): Sukkulentenlexikon Band 2: Zweikeimblättrige Pflanzen (Dicotyledonen) Eugen Ulmer Verlag, Germany 2002. ISBN 3-8001-3915-4