The Mimosoideae are a traditional subfamily of trees, herbs, lianas, and shrubs in the pea family ( Fabaceae) that mostly grow in tropical and subtropical climates. They are typically characterized by having radially symmetric flowers, with petals that are twice divided (valvate) in bud and with numerous showy, prominent stamens. Recent work on phylogenetic relationships has found that the Mimosoideae form a clade nested with subfamily Caesalpinioideae and the most recent classification by ''The Legume Phylogeny Working Group'' refer to them as the Mimosoid clade within subfamily Caesalpinioideae. The group includes about 40 genera and 2,500 species.

Taxonomy

Some classification systems, for example the Cronquist system, treat the Fabaceae in a narrow sense, raising the Mimisoideae to the rank of family as Mimosaceae. The

Angiosperm Phylogeny Group The Angiosperm Phylogeny Group (APG) is an informal international group of systematic botanists who collaborate to establish a consensus on the taxonomy of flowering plants (angiosperms) that reflects new knowledge about plant relationships disc ...

treats Fabaceae in the broad sense. The Mimosoideae were historically subdivided into four tribes (Acacieae, Ingeae, Mimoseae, and Mimozygantheae). However, modern

molecular phylogenetics 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 ...

has shown that these groupings were artificial. Several informal subgroups have been proposed, but not yet described formally as tribes. Additionally, the genus ''Acacia'' was recently segregated into five genera (''Acacia sensu stricto'', ''Acaciella'', ''Mariosousa'', ''Senegalia'', and ''Vachellia'').

Basal Mimosoideae

* ''Adenanthera'' group ** '' Adenanthera'' L. ** ''

Amblygonocarpus ''Amblygonocarpus'' is a genus of flowering plants in the legume family, Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family ...

'' Harms ** '' Calpocalyx'' Harms ** ''

Pseudoprosopis ''Pseudoprosopis'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae ...

'' Harms ** '' Tetrapleura'' Benth. ** ''

Xylia ''Xylia'' is a genus of flowering plants in the family Fabaceae. It is native to Sub-Saharan Africa, South Asia, and Mainland Southeast Asia. Species ''Xylia'' includes nine accepted species: * '' Xylia africana'' Harms * ''Xylia evansii'' Hut ...

'' Benth. * ''Entada'' group ** ''

Elephantorrhiza ''Elephantorrhiza'' is a genus of flowering plants in the family Fabaceae. It has the following species: * ''Elephantorrhiza burkei'' Benth. * ''Elephantorrhiza elephantina'' (Burch.) Skeels * ''Elephantorrhiza goetzei'' (Harms) Harms * ''Ele ...

'' Benth. ** ''

Entada ''Entada'' is a genus of flowering plants in the family Fabaceae, in the mimosoid clade of the subfamily Caesalpinioideae. It consists of some 30 species of trees, shrubs and tropical lianas. About 21 species are known from Africa, six from A ...

'' Adans. ** ''

Piptadeniastrum ''Piptadeniastrum'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade in the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae ...

'' Brenan * ''Newtonia'' group ** '' Fillaeopsis'' Harms ** ''

Indopiptadenia ''Indopiptadenia'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade in the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae ...

'' Brenan ** ''

Lemurodendron ''Lemurodendron'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade in the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae ...

'' Villiers & P. Guinet ** '' Newtonia'' Baill. * ''Prosopis'' group ** ''

Prosopis ''Prosopis'' is a genus of flowering plants in the family Fabaceae. It contains around 45 species of spiny trees and shrubs found in subtropical and tropical regions of the Americas, Africa, Western Asia, and South Asia. They often thrive in ari ...

'' L. ** '' Xerocladia'' Harv. * ''Mimozyganthus'' group ** ''

Mimozyganthus ''Mimozyganthus'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae o ...

'' Burkart ** ''

Piptadeniopsis ''Piptadeniopsis'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae ...

'' Burkart ** '' Prosopidastrum'' Burkart * ''Leucaena'' group ** '' Desmanthus'' Willd. ** ''

Kanaloa In the traditions of ancient Hawaii, Kanaloa is a god symbolized by the squid or by the octopus, and is typically associated with Kāne. It is also an alternative name for the island of Kahoolawe. In legends and chants, Kāne and Kanaloa are ...

'' Lorence & K.R.Wood ** ''

Leucaena ''Leucaena'' is a genus of flowering plants in the mimosoid clade of the subfamily Caesalpinioideae of the family Fabaceae. It contains about 24 species of trees and shrubs, which are commonly known as leadtrees. They are native to the Americas, ...

'' Benth. ** ''

Schleinitzia ''Schleinitzia'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae or ...

'' Warb. ex Nevling & Niezgoda * ''Dichrostachys'' group ** '' Alantsilodendron'' Villiers ** '' Calliandropsis'' H.M.Hern. & P.Guinet ** ''

Dichrostachys ''Dichrostachys'' is an Old World genus of flowering plants in the family Fabaceae. Their ''Acacia''-like leaves are bi-pinnately compound. Unlike ''Acacia'' their thorns are hardened branchlets rather than modified stipules. They are native fro ...

'' (DC.) Wight & Arn. ** '' Gagnebina'' Neck. ex DC. * Unassigned ** '' Aubrevillea'' Pellegr. ** ''

Chidlowia ''Chidlowia'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae or Le ...

'' Hoyle ** ''

Cylicodiscus ''Cylicodiscus'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae or ...

'' Harms ** '' Neptunia'' Lour ** ''

Pentaclethra ''Pentaclethra'' is a small genus of trees from the tropics. They are flowering plants in the family Fabaceae. They belong to the mimosoid clade of the subfamily Caesalpinioideae. The name ''Pentaclethra'' is derived from Ancient Greek, ''penta ...

'' Benth. ** '' Plathymenia'' Benth.

''Acacia'' clade

* ''Parkia'' group ** ''

Anadenanthera ''Anadenanthera'' is a genus of South American trees in the Legume family, Fabaceae. The genus contains two to four species, including '' A. colubrina'' and '' A. peregrina''. These trees respectively are known to the western world primarily a ...

'' Speg. ** '' Parkia'' R.Br. * ''Piptadenia'' group ** ''

Adenopodia ''Adenopodia'' is a genus of legume in the family Fabaceae, that occurs in the northern Neotropical realm, Neotropics and Africa. They may grow as lianas, shrubs or trees. The petioles have a distinct gland above their base, hence the Greek langu ...

'' C.Presl ** ''

Microlobius ''Microlobius'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae or ...

'' C.Presl ** ''

Mimosa ''Mimosa'' is a genus of about 590 species of herbs and shrubs, in the mimosoid clade of the legume family Fabaceae. The generic name is derived from the Greek word (''mimos''), an "actor" or "mime", and the feminine suffix -''osa'', "resemb ...

'' L. ** '' Parapiptadenia'' Brenan ** ''

Piptadenia ''Piptadenia'' is a genus of tropical shrubs and trees of the family Fabaceae. Species *'' Piptadenia adiantoides'' (Sprengel) Macbr. *''Piptadenia affinis'' Burkart *''Piptadenia anolidurus'' Barneby *'' Piptadenia buchananii'' *'' Piptadenia ...

'' Benth. ** ''

Pityrocarpa ''Pityrocarpa'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabaceae or ...

'' Britton & Rose ** '' Pseudopiptadenia'' Rauschert ** ''

Stryphnodendron ''Stryphnodendron'' is a genus of flowering plant in the family Fabaceae. It belongs to the Mimosoideae, mimosoid clade of the subfamily Caesalpinioideae. Species ''Stryphnodendron'' comprises the following species: * ''Stryphnodendron adstringe ...

'' Mart. * ''Abarema'' group ** ''

Abarema ''Abarema'' is a neotropical genus of large trees in the family ( Fabaceae). They grow from Mexico (''Abarema idiopoda'') to Bolivia. Most of the species can be found in the Amazon Basin and the Guyana Highlands. They have a deep-green fernli ...

'' Pittier ** '' Balizia'' Barneby & J.W.Grimes ** '' Hydrochorea'' Barneby & J.W.Grimes * Ingeae grade ( Paraphyletic) ** '' Acaciella'' Britton & Rose ** '' Afrocalliandra'' E.R. Souza & L.P. Queiroz ** ''

Albizia ''Albizia'' is a genus of more than 160 species of mostly fast-growing subtropical and tropical trees and shrubs in the subfamily Mimosoideae of the family Fabaceae. The genus is pantropical, occurring in Asia, Africa, Madagascar, America and A ...

'' Durazz. ** ''

Archidendron ''Archidendron'' is a genus of flowering plants in the pea family, Fabaceae. Image:Archidendron lucyii foliage.jpg, ''Archidendron lucyii'' leaves Image:Pithecellobium jiringa.JPG, ''Archidendron pauciflorum'' fruits Image:Archidendron lucyii f ...

'' F.Muell. ** '' Archidendropsis'' I.C.Nielsen ** ''

Blanchetiodendron ''Blanchetiodendron'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae Caesalpinioideae is a botanical name at the rank of subfamily, placed in the large family Fabace ...

'' Barneby & J.W.Grimes ** ''

Calliandra ''Calliandra'' is a genus of flowering plants in the pea family, Fabaceae, in the mimosoid clade of the subfamily Caesalpinioideae. It contains about 140 species that are native to tropical and subtropical regions of the Americas. Description T ...

'' Benth. ** '' Cathormion'' (Benth.) Hassk. ** '' Cedrelinga'' Ducke ** '' Chloroleucon'' (Benth.) Britton & Rose ** ''

Cojoba ''Cojoba'' is a genus of flowering plants in the family Fabaceae. Selected species * ''Cojoba arborea ''Cojoba arborea'' (common names include algarrobo, ardillo, lorito, barba de jolote, iguano, quebracho, sang sang, tamarindo, tambrán, t ...

'' Britton & Rose ** ''

Enterolobium ''Enterolobium'' is a genus of 12 species of flowering plants in the family Fabaceae, native to tropical and warm-temperate regions of the Americas. They are medium-sized to large trees.Germplasm Resources Information Network''Enterolobium''Inter ...

'' Mart. ** '' Faidherbia'' A.Chev. ** '' Falcataria'' (I.C.Nielsen) Barneby & J.W.Grimes ** '' Hesperalbizia'' Barneby & J.W.Grimes ** ''

Inga ''Inga'' is a genus of small tropical, tough-leaved, nitrogen-fixing treesElkan, Daniel. "Slash-and-burn farming has become a major threat to the world's rainforest" ''The Guardian'' 21 April 2004 and shrubs, subfamily Mimosoideae. ''Inga''s ...

'' Mill. ** '' Leucochloron'' Barneby & J.W.Grimes ** ''

Lysiloma ''Lysiloma'' is a genus of flowering plants in the family Fabaceae. The genus is native to the Americas, and species range from Arizona and New Mexico through Mexico and Central America to Costa Rica, and in Florida, Cuba, Hispaniola, the Baham ...

'' Benth. ** '' Macrosamanea'' Britton & Rose ** '' Pararchidendron'' I.C.Nielsen ** '' Pseudosamanea'' Harms ** ''

Samanea ''Samanea'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae. The type species is ''Samanea saman'' from South America. Taxonomy The name Samanea comes from ''saman' ...

'' (Benth.) Merr. ** ''

Sanjappa ''Sanjappa'' is a genus of flowering plants in the family Fabaceae The Fabaceae or Leguminosae,Serianthes'' Benth. ** ''

Thailentadopsis ''Thailentadopsis'' is a genus of flowering plants in the family Fabaceae. It includes three species of shrubs and small trees, one each native to Sri Lanka, Thailand, and Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the ...

'' Kosterm. ** '' Viguieranthus'' Villiers ** '' Wallaceodendron'' Koord. ** '' Zapoteca'' H.M.Hern. ** ''

Zygia ''Zygia'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae. Selected species * '' Zygia cataractae'' (Kunth) L.Rico * '' Zygia claviflora'' (Spruce ex Benth.) Barneby & J ...

'' P.Browne * ''Pithecellobium'' group ** '' Ebenopsis'' Britton & Rose ** '' Havardia'' Small ** ''

Painteria ''Painteria'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae. The genus is native to Mexico Mexico (Spanish: México), officially the United Mexican States, is a ...

'' Britton & Rose ** ''

Pithecellobium ''Pithecellobium'' is a genus of flowering plants in the family Fabaceae. The generic name is derived from the Greek words πίθηκος (''pithêkos''), meaning "ape" or "monkey," and ἐλλόβιον (''ellobion''), meaning "earring," which ...

'' Mart. ** '' Sphinga'' Barneby & J.W.Grimes * Unassigned ** '' Acacia'' Mill. ** ''

Mariosousa ''Mariosousa'' is a genus of 13 species of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae. Members of this genus were formerly considered to belong to the genus ''Acacia''. Restricte ...

'' Seigler & Ebinger ** ''

Paraserianthes ''Paraserianthes'' is a genus of flowering plants in the family Fabaceae. It belongs to the mimosoid clade of the subfamily Caesalpinioideae. Taxonomy ''Paraserianthes'' includes only one species: * ''Paraserianthes lophantha'' (Willd.) I.C.Nie ...

'' I.C.Nielsen ** '' Parasenegalia'' Seigler & Ebinger ** ''

Pseudosenegalia ''Pseudosenegalia'' is a small genus of flowering plants in the legume family, Fabaceae. It belongs to the subfamily Mimosoideae. It is endemic to Bolivia. Species list The genus ''Pseudosenegalia'' comprises the following species: * '' Pseudose ...

'' Seigler & Ebinger ** ''

Senegalia ''Senegalia'' (from Senegal and ''Acacia senegal'' (L.) Willd.) is a genus of flowering plants in the family Fabaceae. It belongs to the Mimosoid clade. Until 2005, its species were considered members of ''Acacia.'' The genus was considered poly ...

'' Raf. ** ''

Vachellia ''Vachellia'' is a genus of flowering plants in the legume family, Fabaceae, commonly known as thorn trees or acacias. It belongs to the subfamily Mimosoideae. Its species were considered members of genus '' Acacia'' until 2009. ''Vachellia'' ...

'' Wight & Arn.

Fossils

The following fossil wood morphogenera have been described: * †''Acacioxylon'' Schenk 1883 * †''Adenantheroxylon'' Prakash & Tripathi 1968 * †''Albizinium'' Prakash 1975 * †''Albizzioxylon'' Nikitin 1935 * †''Anadenantheroxylon'' Brea et al. 2001 * †''Cathormion'' Gros 1990 * †''Dichrostachyoxylon'' Müller-Stoll & Mädel 1967 * †''Eucacioxylon'' Müller-Stoll & Mädel 1967 * †''Ingoxylon'' Müller-Stoll & Mädel 1967 * †''Menendoxylon'' Lutz 1979 * †''Metacacioxylon'' Gros 1981 * †''Microlobiusxylon'' Franco & Brea 2010 * †''Mimosoxylon'' Müller-Stoll & Mädel 1967 * †''Mimosaceoxylon'' Lakhanpal & Prakash1970 * †''Paraalbizioxylon'' Gros 1992 * †''Paracacioxylon'' Müller-Stoll & Mädel 1967 * †''Piptadenioxylon'' Suguio & Mussa 1978 * †''Prosopisinoxylon'' Martínez * †''Tetrapleuroxylon'' Müller-Stoll & Mädel 1967

Systematics

Modern

suggests the following relationships:

Acacieae

Acacia catechu - Köhler–s Medizinal-Pflanzen-003

Acacieae ( Dumort., 1829) is a wide-ranging,

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of conver ...

tribe of legumes in the Mimosoideae that is native to the

tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referr ...

, subtropics, and warm-temperate regions. It includes five or six genera and some 1,450 species. * Subdivision – 5 or 6 genera ** '' Acacia'' Mill. – type genus ** ''

'' Wight & Arn. ** ''

'' Rafinesque ** '' Acaciella'' Britton & Rose ** ''

'' Seigler & Ebinger ** '' Racosperma'' Martius

Relationships

In Bentham's 1842

circumscription Circumscription may refer to: *Circumscribed circle * Circumscription (logic) *Circumscription (taxonomy) *Circumscription theory, a theory about the origins of the political state in the history of human evolution proposed by the American anthrop ...

of the subfamily Mimosoideae, Acacieae was one of its three constituent tribes, the others being Ingeae Benth. & Hook.f. and Mimoseae Bornn. His Acacieae tribe of 1842 included many genera that were subsequently assigned to tribe Ingeae Benth. In 1875, however, Bentham narrowed his definition of Acacieae so as to include only '' Acacia'' Mill. The only morphological character of Acacieae used to distinguish it from the Ingeae is the presence of free stamens (as in tribe Mimoseae). In the Ingeae they are fused in the form of a tube, whereas in the Acacieae only a few species have the stamens fused at the base. Several characters of the foliage, seeds, seed pods, pollen, and stipules are shared by the two tribes. The flower morphology of ''Acacia s.l.'' has characteristics in common with the genera ''

'', ''

'', and ''

'' (tribe Mimoseae) and ''

'' and ''

'' (tribe Ingeae). The tribal position of monotypic genus '' Faidherbia'' A. Chevalier is equivocal. It was included in the Acacieae by Vassal (1981) and Maslin et al. (2003), but Lewis & Rico Arce placed it in tribe Ingeae following Polhill (1994) and Luckow et al. (2003). In the latter case, tribe Acacieae may conform to genus '' Acacia s.l.'', pending the latter's relationship to other mimosoid genera. ''Faidherbia'' is troublesome as its stamens are shortly united at their base and its pollen is similar to some taxa in the Ingeae.

Description

They are trees, shrubs or lianas, which may be armed or unarmed. Where they have spines, these are modified stipules. In some, prickles arise from the stem's cortex and epidermis. The leaves are bipinnate or are modified to vertically oriented phyllodes. A few have cladodes rather than leaves. Extrafloral nectaries may be present on the petiole and rachis, and the pinnule tips may carry protein-lipid

Beltian bodies A Beltian body is a detachable tip found on the pinnules of some species of '' Acacia'' and closely related genera. Beltian bodies, named after Thomas Belt, are rich in lipids, sugars and proteins and often red in colour. They are believed to have ...

. The leaflets are usually opposite, and are carried on shortly stalks or are sessile. The heartwood is typically red and hard, and the sap of various species hardens into gum. The inflorescences are dense pedunculate heads or spikes borne in axillary clusters, or are aggregated in terminal panicles. The tetra- or pentamerous flowers are uniformly bisexual, or male and bisexual. Sepals are connate (i.e. fused) and valvate (i.e. not overlapping). The reduced petals are valvate, or rarely absent. The flowers have numerous exserted (i.e. protruding) stamens (>2× as many as the corolla lobes), and their filaments are sometimes connate at their base (forming a short stemonozone). Male flowers of some

Neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bioge ...

species have a reduced staminal tube (cf. '' A. albicorticata'', '' A. hindsii'', '' A. farnesiana'', and '' S. picachensis''). Flowers are usually yellow or cream-coloured, but may be white, red, or purple. The ovary is sessile or stipitate (i.e. supported by a stipe), with many ovules or ovules arranged in two rows. The ovary is attached by a filiform style to a small, capitate stigma. The legume's endocarp is attached to the exocarp, but is otherwise very variable, and may be dehiscent or indehiscent. Seeds are usually elliptic to oblong and flattened to varying degrees. Seeds have a hard black-brown testa (i.e. seed coat) with a pleurogram, visible as a closed or almost closed O-shaped line. Some phyllodinous species have a colourful aril or

elaiosome Elaiosomes ( grc, ἔλαιον ''élaion'' "oil" + ''sóma'' "body") are fleshy structures that are attached to the seeds of many plant species. The elaiosome is rich in lipids and proteins, and may be variously shaped. Many plants have elaio ...

on the seed.

References

External links

* * {{Authority control Rosid subfamilies Taxa named by Augustin Pyramus de Candolle