Malvales
Encyclopedia
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. As circumscribed by APG II
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...
-system, it includes about 6000 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
within nine families. The order is placed in the eurosids II, which are part of the eudicots
Eudicots
Eudicots and Eudicotyledons are botanical terms introduced by Doyle & Hotton to refer to a monophyletic group of flowering plants that had been called tricolpates or non-Magnoliid dicots by previous authors...
.
The plants are mostly 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; most of its families have a cosmopolitan distribution
Cosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...
in the tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
and subtropics
Subtropics
The subtropics are the geographical and climatical zone of the Earth immediately north and south of the tropical zone, which is bounded by the Tropic of Cancer and the Tropic of Capricorn, at latitudes 23.5°N and 23.5°S...
with limited expansion into temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
regions. An interesting distribution occurs in Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
, where there are three endemic families of Malvales (Sphaerosepalaceae, Sarcolaenaceae and Diegodendraceae).
Many species of Malvaceae s.l. are known for their wood, with that of Ochroma (balsa) being known for its lightness, and that of Tilia
Tilia
Tilia is a genus of about 30 species of trees native throughout most of the temperate Northern Hemisphere. The greatest species diversity is found in Asia, and the genus also occurs in Europe and eastern North America, but not western North America...
(lime, linden, or basswood) as a popular wood for carving. The cacao tree (Theobroma cacao) is used as an ingredient for chocolate
Chocolate
Chocolate is a raw or processed food produced from the seed of the tropical Theobroma cacao tree. Cacao has been cultivated for at least three millennia in Mexico, Central and South America. Its earliest documented use is around 1100 BC...
. Kola nuts (genus Cola
Kola nut
Kola Nut is the nut of the kola tree, a genus of trees native to the tropical rainforests of Africa, classified in the family Malvaceae, subfamily Sterculioideae . It is related to the South American genus Theobroma, or cocoa...
) are notable for their high content of caffeine
Caffeine
Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants...
, and in past were commonly used for preparing of various cola drinks. Other well-known members of Malvales in the APG II sense are daphnes
Daphne (plant)
Daphne is a genus of between 50 and 95 species of deciduous and evergreen shrubs in the family Thymelaeaceae, native to Asia, Europe, and north Africa...
, hibiscus
Hibiscus
Hibiscus is a genus of flowering plants in the mallow family, Malvaceae. It is quite large, containing several hundred species that are native to warm-temperate, subtropical and tropical regions throughout the world...
, hollyhock
Hollyhock
Alcea , commonly known as hollyhocks, is a genus of about 60 species of flowering plants in the mallow family Malvaceae. Most species are native to southwest and central Asia, although a few are native to southeast Europe or Egypt...
s, okra
Okra
Okra is a flowering plant in the mallow family. It is valued for its edible green seed pods. The geographical origin of okra is disputed, with supporters of South Asian, Ethiopian and West African origins...
, baobab trees
Adansonia
Adansonia is a genus of eight species of tree, six native to Madagascar, one native to mainland Africa and the Arabian Peninsula and one to Australia. The mainland African species also occurs on Madagascar, but it is not a native of that island....
, cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
, and kapok
Kapok
Ceiba pentandra is a tropical tree of the order Malvales and the family Malvaceae , native to Mexico, Central America and the Caribbean, northern South America, and to tropical west Africa...
.
The morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
of Malvales is diverse, and there are few common characteristics. Among those most commonly encountered are palmate
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
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....
, connate sepal
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
s, and a specific structure and chemical composition of the seeds. The cortex
Cortex (botany)
In botany, the cortex is the outer layer of the stem or root of a plant, bounded on the outside by the epidermis and on the inside by the endodermis. It is composed mostly of undifferentiated cells, usually large thin-walled parenchyma cells of the ground tissue system. The outer cortical cells...
is often fibrous, built of soft phloem
Phloem
In vascular plants, phloem is the living tissue that carries organic nutrients , in particular, glucose, a sugar, to all parts of the plant where needed. In trees, the phloem is the innermost layer of the bark, hence the name, derived from the Greek word "bark"...
layers.
Families (APG system)
- BixaceaeBixaceaeBixaceae, or the achiote family, is a family of dicotyledonous plants. Under the Cronquist system, it was traditionally placed in the order Violales...
- CistaceaeCistaceaeThe Cistaceae is a small family of plants known for its beautiful shrubs, which are profusely covered by flowers at the time of blossom...
- CochlospermaceaeCochlospermaceaeCochlospermaceae is a family of two genera and 20-25 species of trees and shrubs. They occur widely throughout the tropical regions of the world, but are curiously absent from Malaysia. Most species in this family are mesophytic or xerophytic, growing primarily in drier climates.Some authorities...
- CytinaceaeCytinaceaeCytinaceae is a family of parasitic flowering plant. It comprised two genera, Cytinus and Bdallophytum, totalling ten species.These two genera were formerly placed in family Rafflesiaceae, order Malpighiales. When they were first split out into a separate family, it was placed in Malpighiales, but...
- Diegodendraceae
- DipterocarpaceaeDipterocarpaceaeDipterocarpaceae is a family of 17 genera and approximately 500 species of mainly tropical lowland rainforest trees. The family name, from the type genus Dipterocarpus, is derived from Greek and refers to the two-winged fruit...
- MalvaceaeMalvaceaeMalvaceae, or the mallow family, is a family of flowering plants containing over 200 genera with close to 2,300 species. Judd & al. Well known members of this family include okra, jute and cacao...
- MuntingiaceaeMuntingiaceaeMuntingiaceae is a family of flowering plants, belonging to the rosid order Malvales. It is a small family which consists of three monotypic genera: Dicraspidia, Muntingia and Neotessmannia. They are woody plants of the tropical regions of America. The older Cronquist System places these genera in...
- NeuradaceaeNeuradaceaeNeuradaceae is a family of flowering plant. It comprised three genera — Grielum, Neurada and Neuradopsis — totalling ten species....
- SarcolaenaceaeSarcolaenaceaeThe Sarcolaenaceae are a family of flowering plants endemic to Madagascar. The family includes 40 species of mostly evergreen trees and shrubs in ten genera....
- SphaerosepalaceaeSphaerosepalaceaeSphaerosepalaceae is a family of flowering plants. It contains 14 species of trees and shrubs in two genera, Dialyceras and Rhopalocarpus, all of which are endemic to Madagascar. The family is alternatively known as the Rhopalocarpaceae....
- ThymelaeaceaeThymelaeaceaeThymelaeaceae is a cosmopolitan family of flowering plants composed of 50 genera and 898 species. It was established in 1789 by Antoine Laurent de Jussieu.Thymelaeaceae is in the order Malvales...
Classification
Family boundaries and circumscriptions of the "core Malvales" families Malvaceae, Bombacaceae, Tiliaceae, and Sterculiaceae have long been problematic. A close relationship among these families, and particularly Malvaceae and Bombacaceae, has generally been recognized although until recently most classification systems have maintained them as separate families. With numerous molecular phylogenies showing that Sterculiaceae, Bombacaceae, and Tiliaceae as traditionally defined are either paraphyletic or polyphyletic, a consensus has been emerging that there has been a trend to expand Malvaceae to include these three families. This expanded circumscription of Malvaceae has been recognized in the most recent version of the Thorne system, by the Angiosperm Phylogeny GroupAngiosperm 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...
, and in the most recent comprehensive treatment of vascular plant families and genera, the Kubitzki system
Kubitzki system
A system of plant taxonomy, the Kubitzki system is the product of an ongoing survey of vascular plants, entitled The Families and Genera of Vascular Plants....
(Bayer and Kubitzki, 2003).
The dominant family in the APG II
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...
-system is the extended Malvaceae (Malvaceae sensu lato) with over 4000 species, followed by Thymelaeaceae with 750 species. This expanded circumscription of Malvaceae
Malvaceae
Malvaceae, or the mallow family, is a family of flowering plants containing over 200 genera with close to 2,300 species. Judd & al. Well known members of this family include okra, jute and cacao...
is taken to include the families Bombacaceae
Bombacaceae
Bombacaceae is a family of flowering plants or Angiospermae included within Malvales order. As is true for any botanical name, circumscription and status of the taxon has varied with taxonomic point of view...
, Sterculiaceae
Sterculiaceae
Sterculiaceae is a botanical name for a group of flowering plants at the rank of family, which is now considered obsolete. As is true for any botanical name, the circumscription, status and placement of the taxon has varied with taxonomic point of view...
and Tiliaceae
Tiliaceae
Tiliaceae is a botanical name for a family of flowering plants. Such a family is not part of APG II, but it is found all through the botanical literature and remains prominently listed by nomenclatural databases such as IPNI....
. Under the older Cronquist system
Cronquist system
The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in his texts An Integrated System of Classification of Flowering Plants and The Evolution and Classification of Flowering Plants .Cronquist's system places flowering plants into two...
the order contained these four "core Malvales" families plus the Elaeocarpaceae
Elaeocarpaceae
Elaeaocarpaceae is a family of flowering plants. The family approximately contains 605 species of trees and shrubs in 12 genera. The largest genera are Elaeocarpus, with about 350 species, and Sloanea, with about 150....
and was placed among the Dilleniidae
Dilleniidae
Dillenidae is a botanical name at the rank of subclass....
. Some of the currently included families were placed by Cronquist in the Violales
Violales
Violales is a botanical name of an order of flowering plants and takes its name from the included family Violaceae. The name has been used in several systems, although some systems used the name Parietales for similar groupings...
.