Recent molecular and morphological evidence supports the fact that the Fabaceae are a single monophyletic family. This point of view has been supported not only by the degree of interrelation shown by different groups within the family compared with that found among the Leguminosae and their closest relations, but also by all the recent phylogenetic studies based on DNA sequences. These studies confirm that the Leguminosae are a monophyletic group that is closely related with the Polygalaceae, Surianaceae and Quillajaceae families and that they belong to the order Fabales.
Along with the cereals, some fruits and tropical roots a number of Leguminosae have been a staple human food for millennia and their use is closely related to human evolution.
The name 'Fabaceae' comes from the defunct genus Faba, now included in Vicia. The term "faba" comes from Latin, and appears to simply mean "bean". Leguminosae is an older name still considered valid, and refers to the fruit of these plants, which are called legumes.
Fabaceae range in habit from giant trees (like Koompassia excelsa) to small annualherbs, with the majority being herbaceous perennials. Plants have indeterminate inflorescences, which are sometimes reduced to a single flower. The flowers have a short hypanthium and a single carpel with a short gynophore, and after fertilization produce fruits that are legumes.
The Leguminosae have a wide variety of growth forms including trees, shrubs or herbaceous plants or even vines or lianas. The herbaceous plants can be annuals, biennials or perennials, without basal or terminal leaf aggregations. They are upright plants, epiphytes or vines. The latter support themselves by means of shoots that twist around a support or through cauline or foliar tendrils. Plants can be heliophytes, mesophytes or xerophytes.
Many species have leaves with structures that attract ants that protect the plant from herbivore insects (a form of mutualism). Extrafloral nectaries are common among the Mimosoideae and the Caesalpinioideae, and are also found in some Faboideae (e.g. Vicia sativa). In some Acacia, the modified hollow stipules are inhabited by ants and are known as domatia.
Many Fabaceae host bacteria in their roots within structures called root nodules. These bacteria, known as rhizobia, have the ability to take nitrogen gas (N2) out of the air and convert it to a form of nitrogen that is usable to the host plant ( NO3− or NH3 ). This process is called nitrogen fixation. The legume, acting as a host, and rhizobia, acting as a provider of usable nitrate, form a symbiotic relationship.
In the Caesalpinioideae, the flowers are often zygomorphic, as in Cercis, or nearly symmetrical with five equal petals in Bauhinia. The upper petal is the innermost one, unlike in the Faboideae. Some species, like some in the genus Senna, have asymmetric flowers, with one of the lower petals larger than the opposing one, and the style bent to one side. The calyx, corolla, or stamens can be showy in this group.
In the Mimosoideae, the flowers are actinomorphic and arranged in globose inflorescences. The petals are small and the stamens, which can be more than just 10, have long, coloured filaments, which are the showiest part of the flower. All of the flowers in an inflorescence open at once.
In the Faboideae, the flowers are zygomorphic, and have a specialized structure. The upper petal, called the banner, is large and envelops the rest of the petals in bud, often reflexing when the flower blooms. The two adjacent petals, the wings, surround the two bottom petals. The two bottom petals are fused together at the apex (remaining free at the base), forming a boat-like structure called the keel. The stamens are always ten in number, and their filaments can be fused in various configurations, often in a group of nine stamens plus one separate stamen. Various genes in the CYCLOIDEA (CYC)/DICHOTOMA (DICH) family are expressed in the upper (also called dorsal or adaxial) petal; in some species, such as Cadia, these genes are expressed throughout the flower, producing a radially symmetrical flower.
The ovary most typically develops into a legume. A legume is a simple dry fruit that usually dehisces (opens along a seam) on two sides. A common name for this type of fruit is a "pod", although that can also be applied to a few other fruit types. A few species have evolved samarae, loments, follicles, indehiscent legumes, achenes, drupes, and berries from the basic legume fruit.
The Fabaceae have an essentially worldwide distribution, being found everywhere except Antarctica and the high arctic. The trees are often found in tropical regions, while the herbaceous plants and shrubs are predominant in extratropical regions.
 The rhizobia and their hosts must be able to recognize each other for nodule formation to commence. Rhizobia are specific to particular host species although a rhizobia species may often infect more than one host species. This means that one plant species may be infected by more than one species of bacteria. For example, nodules in Acacia senegal can contain seven species of rhizobia belonging to three different genera. The most distinctive characteristics that allow rhizobia to be distinguished apart are the rapidity of their growth and the type of root nodule that they form with their host. Root nodules can be classified as being either indeterminate, cylindrical and often branched, and determinate, spherical with prominent lenticels. Indeterminate nodules are characteristic of legumes from temperate climates, while determinate nodules are commonly found in species from tropical or subtropical climates. Nodule formation is common throughout the leguminosae, it is found in the majority of its members that only form an association with rhizobia, which in turn form an exclusive symbiosis with the leguminosae (with the exception of Parasponia, the only genus of the 18 Ulmaceae genera that is capable of forming nodules). Nodule formation is present in all the leguminosae sub-families, although it is less common in the Caesalpinioideae. All types of nodule formation are present in the sub-family Papilionoideae: indeterminate (with the meristem retained), determinate (without meristem) and the type included in Aeschynomene. The latter two are thought to be the most modern and specialised type of nodule as they are only present in some lines of the Papilionoideae sub-family. Even though nodule formation is common in the two monophyletic subfamilies Papilionoideae and Mimosoideae they also contain species that do not form nodules. The presence or absence of nodule-forming species within the three sub-families indicates that nodule formation has arisen several times during the evolution of the leguminosae and that this ability has been lost in some lineages. For example, within the genus Acacia, a member of the Mimosoideae, A. pentagona does not form nodules, while other species of the same genus readily form nodules, as is the case for Acacia senegal, which forms both rapidly and slow growing rhizobial nodules.
The order Fabales contains around 7.3% of eudicot species and the greatest part of this diversity is contained in just one of the four families that order contains: Fabaceae. This clade also includes the Polygalaceae, Surianaceae and Quillajaceae families and its origins date back 94 to 89 million years, although it started its diversification some 79 to 74 million years ago. In fact, the leguminosae have diversified during the early tertiary to become a ubiquitous part of the modern earth’s biota, along with many other families belonging to the flowering plants.
The leguminosae have an abundant and diverse fossil record, especially for the Tertiary period. Fossils of flowers, fruit, leaves, wood and pollen from this period have been found in numerous locations. The earliest fossils that can be definitively assigned to the leguminosae appeared in the late Palaeocene (approximately 56 million years ago). Representatives of the 3 sub-families traditionally recognised as being members of the Leguminosae - Cesalpinioideae, Papilionoideae and Mimosoideae — as well as members of the large clades within these sub-families - such as the genistoides – have been found in periods a little later, starting between 55 to 50 million years ago. In fact, a wide variety of taxa representing the main Leguminosae lineages have been found in the fossil record dating from the middle to the late Eocene, suggesting that the majority of the modern fabaceae groups were already present and that a broad diversification occurred during this period. Therefore, the Fabaceae started their diversification approximately 60 million years ago and the most important clades separated some 50 million years ago. The age of the main Cesalpinioideae clades have been estimated as between 56 and 34 million years and the basal group of the Mimosoideae as 44 ± 2.6 million years. The division between Mimosoideae and Faboideae is dated as occurring between 59 and 34 million years ago and the basal group of the Faboideae as 58.6 ± 0.2 million years ago. It has been possible to date the divergence of some of the groups within the Faboideae, even though diversification within each genus was relatively recent. For instance, Astragalus separated from the Oxytropis some 16 to 12 million years ago. In addition, the separation of the aneuploid species of Neoastragalus started 4 million years ago. Inga, another genus of the Papilionoideae with approximately 350 species, seems to have diverged in the last 2 million years.
It has been suggested, based on fossil and phylogenetic evidence, that legumes originally evolved in arid and/or semi-arid regions along the Tethys seaway during the Palaeogene Period. However, others contend that Africa (or even the Americas) cannot yet be ruled out as the origin of the family.
The current hypothesis about the evolution of the genes needed for nodulation is that they were recruited from other pathways after a polyploidy event. Several different pathways have been implicated as donating duplicated genes to the pathways need for nodulation. The main donors to the pathway were the genes associated with the arbuscular mycorrhiza symbiosis genes, the pollen tube formation genes and the haemoglobin genes. One of the main genes shown to be shared between the arbuscular mycorrhiza pathway and the nodulation pathway is SYMRK and it is involved in the plant-bacterial recognition. The pollen tube growth is similar to the infection thread development in that infection threads grow in a polar manner that is similar to a pollen tubes polar growth towards the ovules. Both pathways include the same type of enzymes, pectin-degrading cell wall enzymes. The enzymes needed to reduce nitrogen, nitrogenases, require a substantial input of ATP but at the same time are sensitive to free oxygen. To meet the requirements of this paradoxical situation, the plants express a type of haemoglobin called leghaemoglobin that is believed to be recruited after a duplication event. These three genetic pathways are believed to be part of a gene duplication event then recruited to work in nodulation.
The phylogeny of the legumes has been the object of many studies by research groups from around the world. These studies have used morphology, DNA data (the chloroplastintrontrnL, the chloroplast genesrbcL and matK, or the ribosomal spacers ITS) and cladistic analysis in order to investigate the relationships between the family’s different lineages. The studies have confirmed that the traditional sub-families Mimosoideae and Papilionoideae are each monophyletic but both are nested within the paraphyletic sub-family Caesalpinioideae. All the different approaches have yielded similar results regarding the relationships between the family's main clades, as shown in the cladogram below.
These three subfamilies have been alternatively treated at the family level, as in the Cronquist and Dahlgren systems. However, this choice has not been supported by late 20th and early 21st century evidence, which has shown the Caesalpinioideae to be paraphyletic and the Fabaceae sensu lato to be monophyletic. While the Mimosoideae and the Faboideae are largely monophyletic, the Caesalpinioideae appear to be paraphyletic and the tribe Cercideae is probably sister to the rest of the family. Moreover, there are a number of genera whose placement into the Caesalpinioideae is not always agreed on (e.g. Dimorphandra).
Legumes are economically and culturally important plants due to their extraordinary diversity and abundance, the wide variety of edible vegetables they represent and due to the variety of uses they can be put to: in horticulture and agriculture, as a food, for the compounds they contain that have medicinal uses and for the oil and fats they contain that have a variety of uses.
The history of legumes is tied in closely with that of human civilization, appearing early in Asia, the Americas (the common bean, several varieties) and Europe (broad beans) by 6,000 BCE, where they became a staple, essential as a source of protein.
Their ability to fix atmospheric nitrogen reduces fertilizer costs for farmers and gardeners who grow legumes, and means that legumes can be used in a crop rotation to replenish soil that has been depleted of nitrogen. Legume seeds and foliage have a comparatively higher protein content than non-legume materials, due to the additional nitrogen that legumes receive through the process. Some legume species perform hydraulic lift, which makes them ideal for intercropping.
Farmed legumes can belong to numerous classes, including forage, grain, blooms, pharmaceutical/industrial, fallow/green manure and timber species, with most commercially farmed species filling two or more roles simultaneously.
There are of two broad types of forage legumes. Some, like alfalfa, clover, vetch, and Arachis, are sown in pasture and grazed by livestock. Other forage legumes such as Leucaena or Albizia are woody shrub or tree species that are either broken down by livestock or regularly cut by humans to provide stock feed.
Fallow or green manure legume species are cultivated to be tilled back into the soil to exploit the high nitrogen levels found in most legumes. Numerous legumes are farmed for this purpose, including Leucaena, Cyamopsis and Sesbania.
Natural gums are vegetable exudates that are released as the result of damage to the plant such as that resulting from the attack of an insect or a natural or artificial cut. These exudates contain heterogeneous polysaccharides formed of different sugars and usually containing uronic acids. They form viscous colloidal solutions. There are different species that produce gums. The most important of these species belong to the leguminosae. They are widely used in the pharmaceutical, cosmetic, food and textile sectors. They also have interesting therapeutic properties; for example gum arabic is antitussive and anti-inflammatory. The most well known gums are tragacanth (Astragalus gummifer), gum arabic (Acacia senegal) and guar gum (Cyamopsis tetragonoloba).
The species used to produce dyes include the following: Logwood Haematoxylon campechianum; a large spiny tree that can grow up to 15m tall. Its cork is thin and soft and its wood is hard. The heartwood is used to produce dyes that are red and purple. The histological stain called haematoxylin is produced from this species. Brazilwood tree (Caesalpinia echinata) is similar to the previous tree but smaller and with red or purple flowers. The wood is also used to produce a red or purple dye. The Madras thorn (Pithecallobium dulce) is another spiny tree native to Latin America, it grows up to 4m high and has yellow or green flowers that grow in florets. Its fruit is reddish and is used to produce a yellow dye. Indigo dye is extracted from the True indigo plant Indigofera tinctoria that is native to Asia. In Central and South America dyes are produced from two species related to this species, indigo from Indigofera suffruticosa and Natal indigo from Indigofera arrecta.
Legumes have been used as ornamental plants throughout the world for many centuries. Their vast diversity of heights, shapes, foliage and flower colour means that this family is commonly used in the design and planting of everything from small gardens to large parks. The following is a list of the main ornamental legume species, listed by sub-family.
^ abcWojciechowski, M. F.; Lavin, M.; Sanderson, M. J. (2004). "A phylogeny of legumes (Leguminosae) based on analysis of the plastid matK gene resolves many well-supported sub clades within the family". American Journal of Botany 91 (11): 1846–62. doi:10.3732/ajb.91.11.1846. PMID21652332.
^ abSchrire, B. D.; Lewis, G. P.; Lavin, M. (2005). "Biogeography of the Leguminosae". In Lewis, G; Schrire, G.; Mackinder, B.; Lock, M. Legumes of the world. Kew, England: Royal Botanic Gardens. pp. 21–54. ISBN1-900347-80-6.
^ abInternational Code of Nomenclature for algae, fungi, and plants. Article 18.5 states: "The following names, of long usage, are treated as validly published: ....Leguminosae (nom. alt.: Fabaceae; type: Faba Mill. [= Vicia L.]); … When the Papilionaceae are regarded as a family distinct from the remainder of the Leguminosae, the name Papilionaceae is conserved against Leguminosae."
^ abcdJudd, W. S., Campbell, C. S. Kellogg, E. A. Stevens, P.F. Donoghue, M. J. (2002), Plant systematics: a phylogenetic approach, Sinauer Axxoc, 287-292. ISBN 0-87893-403-0.
^ abcdStevens, P. F. "Fabaceae". Angiosperm Phylogeny Website. Version 7 May 2006. Retrieved 28 April 2008.
^Burnham, R. J., & Johnson, K. R. 2004. South American palaeobotany and the origins of neotropical rain forests. Phil. Trans. Roy. Soc. London B, 359: 1595-1610.
^ abLewis G., Schrire B., Mackinder B. and Lock M. 2005. (eds.) Legumes of the world. The Royal Botanic Gardens, Kew, Reino Unido. 577 pages. 2005. ISBN 1-900347-80-6.
^Doyle, J. J., J. A. Chappill, C.D. Bailey, & T. Kajita. 2000. Towards a comprehensive phylogeny of legumes: evidence from rbcL sequences and non-molecular data. pp. 1 -20 in Advances in legume systematics, part 9, (P. S. Herendeen and A. Bruneau, eds.). Royal Botanic Gardens, Kew, UK.
^Kajita, T., H. Ohashi, Y. Tateishi, C. D. Bailey, and J. J. Doyle. 2001. rbcL and legume phylogeny, with particular reference to Phaseoleae, Millettieae, and allies. Systematic Botany 26: 515-536.
^ abcBurkart, A. Leguminosas. In: Dimitri, M. 1987. Enciclopedia Argentina de Agricultura y Jardinería. Tomo I. Descripción de plantas cultivadas. Editorial ACME S.A.C.I., Buenos Aires. pages: 467-538.
^Lloret, L. & Martínez-Romero, E. 2005. Evolución y filogenia de Rhizobium. Vol. 47, No. 1-2 pp. 43 - 60. 
^ abcSprent, J. I. 2001. Nodulation in legumes. Royal Botanic Gardens, Kew, UK.
^ abcHerendeen, P. S., W. L. Crepet, and D. L. Dilcher. 1992. The fossil history of the Leguminosae: phylogenetic and biogeographic implications. Pages 303 – 316 in Advances in Legume Systematics, part 4, the fossil record (P. S. Herendeen and D .L. Dilcher, eds). Royal Botanic Gardens, Kew, UK.
^Crepet, W. L., and D. W. Taylor. 1985. The diversification of the Leguminosae: first fossil evidence of the Mimosoideae and Papilionoideae. Science 288: 1087-1089.
^Crepet, W. L., and D. W. Taylor. 1986. Primitive mimosoid flowers from the Palaeocene-Eocene and their systematic and evolutionary implications. American J. Botany 73: 548-563.
^Crepet, W. L., and P. S. Herendeen. 1992. Papilionoid flowers from the early Eocene of south eastern North America. Pages 43–55 in Advances in Legume Systematics, part 4, the fossil record (P. S. Herendeen and D. L. Dilcher, eds.). Royal Botanic Gardens, Kew, UK.
^Herendeen, P. S. 1992. The fossil history of Leguminosae from the Eocene of south eastern North America. Pages 85-160 in Advances in Legume Systematics, part 4, the fossil record (Herendeen, P. S., and D. L. Dilcher, eds.). Royal Botanic Gardens, Kew, UK.
^Herendeen, P. S. 2001. The fossil record of the Leguminosae: recent advances. In Legumes Down Under: the Fourth International Legume conference, Abstracts, 34–35. Australian National University, Canberra, Australia.
^Herendeen, P. S., and S. Wing. 2001. Papilionoid legume fruits and leaves from the Palaeocene of north western Wyoming. Botany 2001 Abstracts, published by Botanical Society of America (http://www.botany2001.org/).
^Wing, S. L., F. Herrera, and C. Jaramillo. 2004. A Palaeocene flora from the Cerrajón Formation, Guajíra Peninsula, north eastern Colombia. Pages 146-147 in VII International Organization of Paleobotany Conference Abstracts (21–26 March). Museo Egidio Feruglio, Trelew, Argentina.
^Bruneau, A., Lewis, G. P., Herendeen, P. S., Schrire, B., & Mercure, M. 2008b. Biogeographic patterns in early-diverging clades of the Leguminosae. Pp. 98-99, in Botany 2008. Botany without Borders. [Botanical Society of America, Abstracts.]
^Bruneau, A., Mercure, M., Lewis, G. P., y Herendeen, P. S. (2008). "Phylogenetic patterns and diversification in the caesalpinioid legumes". Canadian Journal of Botany 86 (7): 697–718. doi:10.1139/B08-058.
^Wikström, N. et ál. (2001), Savolainen, V., & Chase, M. W. 2001. Evolution of the angiosperms: Calibrating the family tree. Proc. Roy. Soc. London B, 268: 2211-2220.
^Wojciechowski, M. F. 2003. Reconstructing the phylogeny of legumes (Leguminosae): An early 21st century perspective. Pp. 5-35, in Klitgaard, B. B. & Bruneau, A. (eds), Advances in Legume Systematics, Part 10, Higher Level Systematics. Royal Botanic Gardens, Kew.
^Wojciechowski, M. F. 2004. Astragalus (Fabaceae): A molecular phylogenetic perspective. Brittonia 57: 382-396.
^Wojciechowski, M. F. Sanderson, M. J., Baldwin, B. G., & Donoghue, M. J. 1993. Monophyly of aneuploid Astragalus: Evidence from nuclear ribosomal DNA internal transcribed spacer sequences. American J. Bot. 80: 711-722.
^Schrire, B. D.; Lavin, M.; Lewis, G. P. (2005). "Global distribution patterns of the Leguminosae: insights from recent phylogenies". In Friis, I; Balslev, H. Plant diversity and complexity patterns: local, regional and global dimensions. Biologiske Skrifter 55. Viborg, Denmark: Special-Trykkeriet Viborg A/S. pp. 375–422. ISBN87-7304-304-4.
^Pan, Aaron D.; Jacobs, Bonnie F.; Herendeen, Patrick S. (2010). "Detarieae sensu lato (Fabaceae) from the Late Oligocene (27.23 Ma) Guang River flora of north-western Ethiopia". Botanical Journal of the Linnean Society 163: 44. doi:10.1111/j.1095-8339.2010.01044.x.
^Käss, E., and M. Wink. 1996. Molecular evolution of the Leguminosae: phylogeny of the three subfamilies based on rbcL sequences. Biochemical Systematics and Evolution 24: 365-378.
^Käss, E., and M. Wink. 1997. Phylogenetic relationships in the Papilionoideae (Family Leguminosae) based on nucleotide sequences of cpDNA (rbcL) and ncDNA (ITS1 and 2). Molecular Phylogenetics and Evolution 8:65-88.
^Doyle, J.J., J.L. Doyle, J.A. Ballenger, E.E. Dickson, T. Kajita, and H. Ohashi. 1997. A phylogeny of the chloroplast gene rbcL in the Leguminosae: taxonomic correlations and insights into the evolution of nodulation. American J. Botany 84: 541-554.
^Lavin, M., J. J. Doyle, and J. D. Palmer. 1990. Evolutionary significance of the loss of the chloroplast--DNA inverted repeat in the Leguminosae subfamily Papilionoideae. Evolution 44: 390-402.
^Sanderson, M. J., and M. F. Wojciechowski. 1996. Diversification rates in a temperate legume clade: are there "so many species" of Astragalus (Fabaceae)? American J. Botany 83: 1488-1502.
^Chappill, J. A. 1995. Cladistic analysis of the Leguminosae: the development of an explicit hypothesis. Pages 1-10 in Advances in Legume Systematics, part 7, phylogeny (M. D. Crisp and J. J. Doyle, eds.). Royal Botanic Gardens, Kew, UK.
^Bruneau A, Mercure M, Lewis GP, Herendeen PS. (2008). "Phylogenetic patterns and diversification in the caesalpinioid legumes". Botany 86 (7): 697–718. doi:10.1139/B08-058.
^The gene bank and breeding of grain legumes (lupine, vetch, soya and beah) / B.S. Kurlovich and S.I. Repyev (Eds.), - St. Petersburg, The N.I. Vavilov Institute of Plant Industry, 1995, 438p. - (Theoretical basis of plant breeding. V.111)
^Kuklinski, C. 2000. Farmacognosia : estudio de las drogas y sustancias medicamentosas de origen natural. Ediciones Omega, Barcelona. ISBN 84-282-1191-4
^Marquez, A. C., Lara, O.F., Esquivel, R. B. & Mata, E. R. 1999. Composición, usos y actividad biológica: Plantas medicinales de México II. UNAM. First edition. México, D.F.
^Ministerio de Educación de la Nación. Subsecretaría de Coordinación Administrativa. Día de la Flor Nacional "El Ceibo". Efemérides Culturales Argentinas. Consulted 3 March 2010.
^Gilbert Vargas Ulate. 1997. Geografía turística de Costa Rica. EUNED, 180 p. ISBN 9977-64-900-6, 9789977649009.
^"Lei Nº 6.607, de 7 de dezembro de 1978. O Presidente da República, faço saber que o Congresso Nacional decreta e eu sanciono a seguinte Lei: Art. 1º- É declarada Árvore Nacional a leguminosa denominada Pau-Brasil (Caesalpinia echinata, Lam), cuja festa será comemorada, anualmente, quando o Ministério da Educação e Cultura promoverá campanha elucidativa sobre a relevância daquela espécie vegetal na História do Brasil."
"If you take some dry legume seeds and immerse them in water they swell up. If they're put in a closed chamber into which water can pass but out of which they can't squeeze or ooze, then their swelling will push outward on the chamber with surprising force…The affinity of many polysaccharides and proteins for water is extreme--the resulting pressures may reach thousands of atmospheres. (Salisbury and Ross  give references to experiments and calculations.) Wetting of a small quantity of dry seeds accidentally left underneath can lead to the fracture of concrete pavement." (Vogel 2003:443-444) Learn more about this functional adaptation.
Steven Vogel. 2003. Comparative Biomechanics: Life's Physical World. Princeton: Princeton University Press. 580 p.
Barcode of Life Data Systems (BOLD) Stats Specimen Records:20754 Specimens with Sequences:23856 Specimens with Barcodes:16500 Species:6465 Species With Barcodes:6163 Public Records:12642 Public Species:5126 Public BINs:0
Trees or shrubs (in ours). Leaves alternate, 2-pinnate or (in some introduced species) modified to phyllodes which look like simple leaves. Inflorescences usually spikes, racemes or heads of small, actinomorphic (3-)5(-6)-merous flowers. Sepals usually united to form a calyx. Petals valvate in bud, free, or united below into a tube. Stamens 4-10, as many as or twice as many as the petals, or numerous. Pods and seeds various. Seeds generally marked with an areole.
Trees or shrubs, less often climbers or herbs. Leaves usually 1-pinnate, less often simple or 2-pinnate. Inflorescences usually of spikes or panicles of racemes, rarely of spikes or capitate; racemes sometimes condensed to umbel-like fascicles. Flowers usually ± zygomorphic. Sepals usually free, sometimes ± connate. Petals imbricate in bud, usually with the dorsal within and overlapped by the lateral, free or sometimes connate below, usually 5, sometimes reduced to 1 or 0. Stamens usually 10 or fewer (rarely numerous), free or ± connate below. Pods various. Seeds generally without areoles.