Description:

• Annual or perennial herbs, erect or often prostrate
• Leaves paripinnately 4-foliolate, rarely 3-foliolate; exstipellate; stipules partly adnate to petiole, membranous, apiculate, persistent and veined
• Flowers yellow, sometimes striped with red, in axillary, short, dense, sessile, 2-7-flowered spikes; bracts membranous; bracteoles 0
• Calyx membranous, filiform, 5-lobed, the upper 4 lobes joined, the lower ± free
• Petals: vexillum suborbicular, shortly narrowed at base; wings oblong, free; keel beaked, incurved
• Stamens all connate into a closed tube; 4 or 5 anthers elongate and subbasifixed, alternating with 4 or 5 short and versatile ones
• Ovary subsessile, 2-4-ovuled; style filiform, very long, soon deciduous; stigma minute, terminal
• Pod maturing below soil, oblong or sausage-shaped, 1-6-seeded, constricted between seeds but not articulated, continuous inside, functionally indehiscent, walls thick and reticulate
• Seeds ovoid or oblong
• x = 10 (5) (aneuploids, polyploidy)

Nomenclature:

• *Arachis L.
  • Linnaeus:741 (1753)
  • Hutchinson: 486 (1964)
  • Verdcourt: 440 (1971)

Distribution & Notes:

• Global: Species ± 22 in South America, introduced elsewhere in tropics and warm temperate areas
• Southern Africa: Species 1: *Arachis hypogaea L., the Groundnut, has become naturalised as an escape from cultivation