Family:
Fabaceae Lindl.

Arachis L.

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

[FSOM]

M. Thulin et al. Flora of Somalia Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit
Annuals or perennials
Morphology Leaves
Leaves paripinnate with 4 leaflets; stipules partly adnate to the petiole
Morphology Reproductive morphology Inflorescences
Inflorescences axillary short dense sessile spikes or flowers solitary, with primary and secondary bracts; flowers subsessile with a long, filiform, pedicel-like receptacle
Morphology Reproductive morphology Flowers Calyx
Calyx 5-lobed
Morphology Reproductive morphology Flowers Corolla
Corolla yellow, often with red nerves
Morphology Reproductive morphology Flowers Androecium Stamens Filaments
Filaments all joined; anthers 8–10, alternately long and short
Morphology Reproductive morphology Flowers Gynoecium Style
Style very long, filiform, soon breaking off
Morphology Reproductive morphology Fruits
Pod oblong or sausage-shaped, 1–few-seeded, indehiscent, developing below the soil, having been pushed beneath by lengthening, reflexing and stiffening of the gynophore.
Distribution
Some 80 species in S America, one of which, the groundnut, is widely cultivated in the warmer parts of the world.

[FTEA]

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

Morphology General Habit
Annual or perennial erect or prostrate herbs
Morphology Leaves
Leaves paripinnately 4-foliolate, rarely 3-foliolate; stipules partly adnate to the petiole, membranous, apiculate, persistent and veined; stipels absent
Morphology Reproductive morphology Inflorescences
Inflorescences axillary short dense sessile 2–7-flowered spikes; bracts membranous, the primary ones biapiculate; bracteoles absent
Morphology Reproductive morphology Flowers Calyx
Calyx membranous, filiform, 5-lobed, the 4 upper lobes joined, the lower ± free
Morphology Reproductive morphology Flowers
Flowers small or medium-sized, yellow, sometimes striped with red Flowers ± sessile, soon deciduous; receptacle long and filiform, pedicel-like
Morphology Reproductive morphology Flowers Corolla
Standard rounded, shortly narrowed at the base; wings free; keel beaked, incurved
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens all joined, 8–10; 4–5 anthers elongate and subbasifixed, alternating with 4–5 short and versatile ones
Morphology Reproductive morphology Flowers Gynoecium 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
Morphology Reproductive morphology 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
Morphology Reproductive morphology Seeds
Seeds irregularly ovoid or oblong; cotyledons thick and fleshy, rich in oil.

[FZ]

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

Morphology General Habit
Annual or perennial erect or prostrate herbs.
Morphology Leaves
Leaves paripinnately 4-foliolate, rarely 3-foliolate; stipules partly adnate to the petiole, membranous, apiculate, persistent and veined; stipels absent.
Morphology Reproductive morphology Inflorescences
Inflorescences axillary short dense sessile 2–7-flowered spikes; bracts membranous, the primary ones biapiculate; bracteoles absent.
Morphology Reproductive morphology Flowers
Flowers ± sessile, soon deciduous, small or medium-sized, yellow, sometimes striped with red.
Morphology Reproductive morphology Flowers Receptacle
Receptacle long and filiform, pedicel-like; calyx membranous, filiform, 5-lobed, the 4 upper lobes joined, the lower ± free.
Morphology Reproductive morphology Flowers Corolla
Standard rounded, shortly narrowed at the base; wings free; keel beaked, incurved.
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 8–10, all joined; 4–5 anthers elongate and sub-basifixed, alternating with 4–5 short and versatile ones.
Morphology Reproductive morphology Flowers Gynoecium 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.
Morphology Reproductive morphology 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.
Morphology Reproductive morphology 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)

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, Bulgaria, Burkina, Burundi, Cameroon, Caroline Is., Central African Repu, Central European Rus, Chad, China North-Central, China South-Central, China Southeast, Colombia, Comoros, 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, Marianas, 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 Has image?
Alvin, P.T. [s.n.], Brazil K000909002 Yes
Edward, J.T. [s.n.], Brazil K000909003 Yes
Paula-Souza, J. [4645], Brazil K000909001 Yes

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

  • Burkart in Darwiniana 3: 261 (1939).
  • Gen. Pl., ed. 5: 329 (1754).
  • Hermann, U.S. Dept. Agric. Monographs: 19 (1954).
  • Hoehne in Fl. Brasilica 25 (II: 122): 3 (1940).
  • Sp. Pl.: 741 (1753)
  • Verdcourt in Kirkia 9: 495 (1974).

Flora of Somalia

  • Flora Somalia, Vol 1, (1993) Author: by M. Thulin [updated by M. Thulin 2008]

Flora of Tropical East Africa

  • Burkart in Darwiniana 3: 261 (1939)
  • Hermann, U.S. Dept. Agric, Agric. Monographs 19 (1954)
  • Hoehne in Fl. Brasilíca 25 (II: 122): 3 (1940)
  • L., Gen. Pl., ed. 5: 329 (1754)
  • Sp. Pl.: 741 (1753)

  • 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 Somalia

    Flora of Somalia
    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

    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 2022. 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 2022. 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

  • Kew Science Photographs

    Copyright applied to individual images

  • Legumes of the World Online

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