1. Family: Fabaceae Lindl.
    1. Arachis L.

      1. This genus is accepted, and its native range is Bolivia to Brazil and N. Argentina.

    [LOWO]

    Legumes of the World. Edited by G. Lewis, B. Schrire, B. MacKinder & M. Lock. Royal Botanic Gardens, Kew. (2005)

    Note

    The present circumscription of Dalbergieae sens. lat. contains radical changes to Dalbergieae sensu Polhill (1981d: 233–242). In the first instance it takes a traditional view of the tribe by including genera such as Vatairea and Vataireopsis (now in the Vataireoid clade, see Figs. 1& 40) and Andira and Hymenolobium, which in Wojciechowski et al. (2004) are sister to the combined Dalbergioid clade of Lavin et al. (2001a), plus Amorpheae. The bulk of the treatment, however, recognises the cryptic Dalbergioid clade (Lavin et al., 2001a) as comprising tribe Dalbergieae sens. lat., diagnosed by the synapomorphy of aeschynomenoid root nodules. This clade includes all the genera placed in the Dalbergieae sensu Polhill (1981d: 233– 242), the Aeschynomeneae sensu Rudd (1981) and the Adesmieae sensu Polhill (1981g: 355–356), plus subtribe Bryinae of the Desmodieae sensu Ohashi et al. (1981) as well as the genus Diphysa (tribe Robinieae sensu Polhill & Sousa (1981)).The placements of all members of the Dalbergioid clade within the classification presented here and in those of Polhill (1981d: 233–242; 1981g: 355–356), Polhill & Sousa (1981), Ohashi et al. (1981) and Rudd (1981) are listed in Fig. 40.

    Dalbergieae sensu Polhill (1981d) contained 19 genera defined by woody habit, supposedly plesiomorphic flowers, pods with a specialised seed chamber and seeds that accumulated alkaloids. Polhill (1981d) noted that there seemed to be two centres within the Dalbergieae: one around Andira with Hymenolobium, Vatairea, Vataireopsis, Dalbergia, and Machaerium, and one around Pterocarpus. He also highlighted evidence from wood anatomy (Baretta-Kuipers, 1981) which showed that Andira, Hymenolobium, Vatairea, and Vataireopsis have coarser wood structures more typical of members of the Sophoreae than the remaining members of the Dalbergieae. The study of fruit and seedling morphology by Lima (1990) further supported these two centres within the Dalbergieae: one including Andira, Hymenolobium, Vatairea, and Vataireopsis, and the second the remaining genera. Most recently several molecular and morphological studies (e.g., Lavin et al., 2001a; Pennington et al., 2001; Wojciechowski et al., 2004) confirm that these four genera do not belong in the Dalbergioid clade. Since there is, however, still much work to be done to resolve the phylogenetic relationships of these four genera, they have been kept in tribe Dalbergieae sens. lat. in this treatment to avoid tentative placements, which might be treated by users as formal.

    The tribe Aeschynomeneae sensu Rudd (1981) contained 25 genera characterised by lomentaceous pods, although some members lack loments (e.g., Arachis, Ormocarpopsis, Diphysa spp., Ormocarpum spp., and Pictetia spp.). None of the Aeschynomeneae had previously been considered closely related to the Dalbergieae, but the work of Lavin et al. (2001a) has resolved all the ‘aeschynomenoid genera’ within the Dalbergioid clade.

    The taxonomic history of the monogeneric tribe Adesmieae sensu Polhill (1981g) is very different from that of the Dalbergieae. The Adesmieae combines the presumed plesiomorphic trait of free stamen filaments, with presence of lomentaceous pods that are supposedly derived. This combination of features suggested a taxonomically isolated position far removed from the Dalbergieae. The analyses of Lavin et al. (2001a) based on molecular sequence and morphological data, however, support Adesmia (nested together with five genera of Rudd’s Aeschynomeneae) being sister to the Pterocarpus and Dalbergia clades. The neotropical genera Brya and Cranocarpus were placed together in a new subtribe Bryinae of Desmodieae in the classification of Ohashi et al. (1981). The features common to these genera are periporate pollen and glochidiate hairs or glandular trichomes. In the molecular studies of Doyle et al. (1995) and Bailey et al. (1997), Brya and Cranocarpus did not lack the intron for the chloroplast gene rpl2 nor for the open reading frame ORF184, which are characteristic of the other desmodioid genera studied. Bailey et al. (1997), therefore, suggested that Brya and Cranocarpus should be removed from the Desmodieae. Their findings were strongly corroborated by the three gene analyses of Lavin et al. (2001a) which place the two genera in the Pterocarpus clade (Fig. 40).

    One further transfer has been made in the Dalbergioid clade since Rudd (1981) and Polhill & Sousa (1981). Lavin (1987) transferred Diphysa from the Robinieae to tribe Aeschynomeneae based on the absence of canavanine in the seeds, a feature consistently present in the Robinieae (Lavin, 1986). Lavin (1987) also listed 14 morphological characters that placed Diphysa with the Aeschynomeneae rather than the Robinieae. In the phylogenetic analyses of Lavin et al. (2001a), Diphysa is resolved in the Dalbergioid clade nested within the ‘transatlantic clade’ (Fig. 40), first identified by Lavin et al. (2000).

    Finally, since 1981 four new genera have been published: the Brazilian monotypic Grazielodendron (Lima, 1983b), the possibly extinct Madagascan endemic Peltiera (Labat & Du Puy, 1997), Zygocarpum, the Horn of Africa – Arabian segregate of Ormocarpum (Thulin & Lavin, 2001) and Maraniona from northern Peru (Hughes et al., 2004). Three genera have also been placed in synonymy since 1981: the Caribbean genus Belairia which is a synonym of Pictetia (Beyra-Matos & Lavin, 1999), and the genera Pachecoa and Arthrocarpum which Thulin (1999) synonymised under Chapmannia. In this treatment 49 genera and (1319) –1325–(1331) species are recognised in Dalbergieae sens. lat. (including 4 basally branching dalbergioid genera comprising c. 58 species, and (1261)–1267– (1273) species in the 45 genera of the Dalbergioid clade [Lavin et al., 2001a]).The following informal groupings of genera are based on the work of Lavin et al. (2001a): Adesmia clade: 6 genera; c. 360 species; neotropical except Zornia, which is pantropical. Pterocarpus clade: 22 genera; c. 200 species centred in the Neotropics, Pterocarpus and Stylosanthes are pantropical, Inocarpus Asian, and Chapmannia transatlantic.Dalbergia clade: 17 genera; c. 706 species which are pantropical, but centred in Africa; Weberbauerella, Soemmeringia, Pictetia and Diphysa are neotropical, Machaerium transatlantic, Dalbergia and Aeschynomene are pantropical, and Geissaspis Asian. Isolated genera: 4 genera; 58 species, neotropical except Andira, which has one amphiatlantic species.

    Rudd (1981) placed Arachis in tribe Aeschynomeneae, subtribe Stylosanthinae. Lavin et al. (2001a), based on DNA sequence data, resolved Arachis in the Pterocarpus clade as sister to Stylosanthes (Fig. 40)
    Vernacular
    cacahuate
    Habit
    Herbs
    Ecology
    Seasonally drytropical to subtropical, dry and well-drained wooded grassland and grassland
    Distribution
    S America, from SC & E Brazil (most species) west to Bolivia and south to Paraguay, Uruguay and N & NE Argentina; but cultivated pantropically and in warm temperate areas
    [FTEA]

    Leguminosae, J. B. Gillett, R. M. Polhill & B. Verdcourt. Flora of Tropical East Africa. 1971

    Habit
    Annual or perennial erect or prostrate herbs
    Leaves
    Leaves paripinnately 4-foliolate, rarely 3-foliolate; stipules partly adnate to the petiole, membranous, apiculate, persistent and veined; stipels absent
    Inflorescences
    Inflorescences axillary short dense sessile 2–7-flowered spikes; bracts membranous, the primary ones biapiculate; bracteoles absent
    Calyx
    Calyx membranous, filiform, 5-lobed, the 4 upper lobes joined, the lower ± free
    Flowers
    Flowers small or medium-sized, yellow, sometimes striped with red Flowers ± sessile, soon deciduous; receptacle long and filiform, pedicel-like
    Corolla
    Standard rounded, shortly narrowed at the base; wings free; keel beaked, incurved
    Stamens
    Stamens all joined, 8–10; 4–5 anthers elongate and subbasifixed, alternating with 4–5 short and versatile ones
    Pistil
    Ovary subsessile, situated at the base of the receptacular tube, linear, (l–)2–4(–7)-ovuled; style filiform, very long, soon deciduous; stigma minute, terminal
    Fruits
    Fruit oblong or sausage-shaped, 1–6-seeded, restricted between the seeds but not articulated, continuous inside, functionally indehiscent, the walls thick and reticulate, developing below the soil, having been pushed beneath by the considerable lengthening, reflexing and stiffening of the gynophore
    Seeds
    Seeds irregularly ovoid or oblong; cotyledons thick and fleshy, rich in oil.
    [FZ]

    Leguminosae, B. Verdcourt. Flora Zambesiaca 3:6. 2000

    Habit
    Annual or perennial erect or prostrate herbs.
    Leaves
    Leaves paripinnately 4-foliolate, rarely 3-foliolate; stipules partly adnate to the petiole, membranous, apiculate, persistent and veined; stipels absent.
    Inflorescences
    Inflorescences axillary short dense sessile 2–7-flowered spikes; bracts membranous, the primary ones biapiculate; bracteoles absent.
    Flowers
    Flowers ± sessile, soon deciduous, small or medium-sized, yellow, sometimes striped with red.
    Receptacle
    Receptacle long and filiform, pedicel-like; calyx membranous, filiform, 5-lobed, the 4 upper lobes joined, the lower ± free.
    Corolla
    Standard rounded, shortly narrowed at the base; wings free; keel beaked, incurved.
    Stamens
    Stamens 8–10, all joined; 4–5 anthers elongate and sub-basifixed, alternating with 4–5 short and versatile ones.
    Pistil
    Ovary subsessile, situated at the base of the receptacular tube, linear, (1)2–4(7)-ovuled; style filiform, very long, soon deciduous; stigma minute, terminal.
    Fruits
    Fruit oblong or sausage-shaped, 1–6-seeded, somewhat constricted between the seeds but not articulated, continuous inside, functionally indehiscent, the walls thick and reticulate, developing below the soil, having been pushed beneath by the considerable lengthening, reflexing and stiffening of the gynophore.
    Seeds
    Seeds irregularly ovoid or oblong cotyledons thick and fleshy, rich in oil.
    [LOWO]
    Use
    Arachis hypogaea L. (peanut, groundnut) is a major human food and source of vegetable oil (second only to soybean in importance among legumes), and animal fodder (mainly leaves); also used as a soil fertiliser and ground cover; other species are used similarly, but on a more local or regional basis (e.g., A. pintoi Krapov. & W.C.Greg.). Further uses are as medicine and fuels; the oil is the base of numerous industrial products (e.g., polishes, paints, lubricants, insecticides, soaps and cosmetics)

    Images

    Distribution

    Native to:

    Argentina Northeast, Argentina Northwest, Bolivia, Brazil North, Brazil Northeast, Brazil South, Brazil Southeast, Brazil West-Central, Paraguay, Uruguay

    Introduced into:

    Alabama, Angola, Assam, Bangladesh, Belarus, Benin, Burkina, Burundi, Cameroon, Central African Repu, Central European Rus, Chad, China North-Central, China South-Central, China Southeast, Colombia, East European Russia, East Himalaya, Ecuador, Eritrea, Ethiopia, Florida, Gabon, Galápagos, Gambia, Georgia, Ghana, Guinea, Guinea-Bissau, Gulf of Guinea Is., Hainan, Honduras, Illinois, India, Inner Mongolia, Iraq, Ivory Coast, Jawa, Kazakhstan, Kenya, Kirgizstan, Korea, Krym, KwaZulu-Natal, Laccadive Is., Laos, Liberia, Louisiana, Malawi, Malaya, Mali, Manchuria, Mauritania, Mexico Southwest, Mongolia, Mozambique, Myanmar, Namibia, Nepal, New Guinea, Niger, Nigeria, North Caucasus, Northern Provinces, Pakistan, Peru, Philippines, Puerto Rico, Queensland, Rwanda, Santa Cruz Is., Senegal, Sierra Leone, Society Is., South European Russi, Sri Lanka, Sudan, Sumatera, Tadzhikistan, Taiwan, Tanzania, Thailand, Togo, Transcaucasus, Trinidad-Tobago, Turkmenistan, Uganda, Ukraine, Uzbekistan, Venezuela, Vietnam, West Himalaya, Western Australia, Yemen, Zambia, Zaïre, Zimbabwe

    Arachis L. appears in other Kew resources:

    Date Reference Identified As Barcode Type Status
    Paula-Souza, J. [4645], Brazil K000909001
    Alvin, P.T. [s.n.], Brazil K000909002
    Edward, J.T. [s.n.], Brazil K000909003

    First published in Sp. Pl.: 741 (1753)

    Accepted by

    • Govaerts, R. (1995). World Checklist of Seed Plants 1(1, 2): 1-483, 529. MIM, Deurne.

    Literature

    Flora of West Tropical Africa
    • —F.T.A. 2: 157.
    Flora Zambesiaca
    • Verdcourt in Kirkia 9: 495 (1974).
    • Hermann, U.S. Dept. Agric. Monographs: 19 (1954).
    • Hoehne in Fl. Brasilica 25 (II: 122): 3 (1940).
    • Burkart in Darwiniana 3: 261 (1939).
    • Gen. Pl., ed. 5: 329 (1754).
    • Sp. Pl.: 741 (1753)
    Flora of Tropical East Africa
    • Hermann, U.S. Dept. Agric, Agric. Monographs 19 (1954)
    • Hoehne in Fl. Brasilíca 25 (II: 122): 3 (1940)
    • Burkart in Darwiniana 3: 261 (1939)
    • L., Gen. Pl., ed. 5: 329 (1754)
    • Sp. Pl.: 741 (1753)

    Sources

    Art and Illustrations in Digifolia
    Digital Image © Board of Trustees, RBG Kew

    Flora Zambesiaca
    Flora Zambesiaca
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Flora of Tropical East Africa
    Flora of Tropical East Africa
    http://creativecommons.org/licenses/by-nc-sa/3.0

    Herbarium Catalogue Specimens
    'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

    Kew Backbone Distributions
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Kew Names and Taxonomic Backbone
    The International Plant Names Index and World Checklist of Selected Plant Families 2019. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
    © Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

    Legumes of the World Online
    http://creativecommons.org/licenses/by-nc-sa/3.0