Vigna unguiculata (L.) Walp., Rep. 1: 779 (1843).

Reference to a published description: CPV 191; FCBR 387, illust. 389; FE 174; FS 436; FTEA 642; FZ 138; LM 584.

Vernacular names: None known.

Habit and life span: Annual or perennial, erect, trailing or climbing, herb.

Flower colour: White, greenish, yellow or lilac-purple.

Habitat: Both cultivated and wild forms are found in diverse habitats, soils and rock types.

Associated species: Numerous but primarily Acacia, Brachystegia, Combretum, Eragrostis, Hyparrhenia, Terminalia and Urochloa.

Altitude: 1-3650.

Distribution: Widespread throughout Africa.

Phenology: Various.

Uses: Widely cultivated for its edible seeds and leaves which are eaten as a green vegetable.

Taxon Vulnerability Assessment: = 2.6

Conservation Notes: V. unguiculata is the most widely distributed Vigna species in Africa and there are very significant ex situ collections from throughout Africa. As V. unguiculata is such an important source of human and animal feed it is not surprising that so much effort has been devoted to ensuring the gene pool is systematically conserved. In terms of gene pool conservation, with 600 conserved accessions there is little need for further collection of the cultivated material; although with a focus on infra-taxonomic diversity there may be a need for further land race sampling of material not already held ex situ. The trend in numbers of herbarium specimens collected over time follows the general pattern for all Vigna species, which suggests overall the species does not appear to be in danger of extinction or genetic erosion; however, this assessment does not hold true for all subspecies, for subsp. aduensis, baoulensis and berundiensis, see below.

IUCN Red List Category: Least Concern.

Taxonomic notes: The plant is warm-season adapted, annual and an herbaceous legume. Plant types are often categorised as erect, semi-erect, prostrate (trailing), or climbing. Growth habits range from indeterminate to fairly determinate with the non-vining types tending to be more determinate. Cowpea seed ranges in size from the very small wild types up to nearly 14 inches long and the number of seeds per pound range from 1600 to 4300 seeds. Seed shape is a major characteristic correlated with seed development in the pod. Seeds develop a kidney shape if not restricted within the pod. When seed growth is restricted by the pod the seed becomes progressively more globular. The seed coat can be either smooth or wrinkled and of various colours including white, cream, green, buff, red, brown, and black. Seed may also be speckled, mottled, or blotchy. Many are also referred to as "eyed" (blackeye, pinkeye, purple hull, etc.) where the white coloured hilum is surrounded by another colour (Coulibaly et al., 2002).

Maréchal et al (1978) and Pasquet (1998, 2001) recognise four cultivar-groups within this species. These are

i) Biflora: common name Catjang bean, used mainly for forage; flower and seed most often coloured; ovules fewer than 17 per ovary, pod not fleshy, less than 30 cm long, seeds not spaced within the pod, testa thick and shiny, and plant able to flower quickly from the first nodes under short-day conditions.

ii) Sesquipedalis: common name yard-long bean or asparagus bean, grown for its fresh green pods which can grow up to 1 m long and are used as a vegetable, mainly in Asia; ovules more than 17 per ovary; pod fleshy, wrinkled when ripe, more than 30 cm long; seeds reniform, spaced within the pod.

iii) Melanophthalmus: grown for the tough fibres obtained from its peduncles in parts of NGA; flower and seed partly white; ovules fewer than 17 per ovary, pod not fleshy, less than 30 cm long, seeds not spaced within the pod, testa thin and often wrinkled, plant able to flower quickly from the first nodes under short-day conditions.

iv) Unguiculata: common name cowpea / black eye bean; flower and seed often coloured, ovules more than 16 per ovary, pod not fleshy, < 30 cm long, seeds not spaced within the pod, testa thick and shiny, plant flowering late, even under short-day conditions.

This account will only be restricted to the wild forms of this species. A full treatment of the cultivated forms is given by Pasquet, (1998). Revisions have been proposed by various authors including Pienaar and van Wyk, (1991); Pienaar (1992), Mithen and Kibblewhite (1993); Padulosi, (1993), Pasquet (1993a, b, c), Pasquet (1994) as previously discussed. The following key is derived from Pasquet (1993a, 2001):

1. Cultivated plant; pod > 100 x 5 mm . . . . . . . . . . . . . . subsp. unguiculata var. unguiculata 2

Plant wild or weedy; pod < 100 x 5 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2. Flower and seed most often coloured; < 17 ovules per ovary; pods not fleshy, unwrinkled, < 30 cm, seeds not spaced within the pod; seed testa thick and shiny . . . . . . . . . . . . . cv Biflora

Flower and seed often coloured; > 17 ovules per ovary; pods fleshy, wrinkled when ripe, up to 1 m, seeds spaced within the pod; seeds reniform . . . . . . . . . . . . . . . . . . . cv Sesquipedalis

Flower and seed partly white; < 17 ovules per ovary, pod not fleshy, unwrinkled, < 30 cm, seeds not spaced within the pod; seed testa thin and often wrinkled . . . cv Melanophthalmus

Flower and seed often coloured; > 17 ovules per ovary, pod not fleshy, < 30 cm, seeds not spaced within the pod, testa thick and shiny . . . . . . . . . . . . . . . . . . . . . . . . . . cv Unguiculata

3. Keel with a marked beak, 6-8 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Keel without a beak or with a short beak < 3 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4. Leaflet thick, obtuse at apex, inflorescence 2-5-noded, internode 2-4 mm, flowers 24-33 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . subsp. dekindtiana

Leaflet small, acute at apex, inflorescence multi-noded, short internode, flowers (16-)18-23(-25) mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . subsp. alba

5. Keel twisted towards the left, without a beak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Keel twisted towards the right, with a short beak up to 3 mm long . . . . . . . . . . . . . . . . . . . . 9

6. Calyx teeth 0.5-6 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Calyx teeth 5-15 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

7. Calyx teeth 2.0-6.0 mm; flower 16-21 mm; ovary 10-14-ovuled . . . . . . . . subsp. stenophylla

Calyx teeth 0.5-2.0 mm; flower (21-)26-38 mm; ovary ± 17-ovuled . . . . . . subsp. baoulensis

8. Stipules 12-27 mm; rachis 5-25 mm, 3-10-noded; ovary 18-20 ovules . . . . . . subsp. aduensis

Stipules 6-20 mm; rachis 5 mm, 3-4-noded; ovary 15-18 ovules . . . . . . . . . . subsp. pawekiae

9. Plant pubescent; rachis internodes long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . subsp. pubescens

Plant scabrous or glabrous; rachis internodes short . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

10. Inflorescence rachis 1-2-noded; plant with a rootstock; leaflets rhombic . . . . . . subsp. tenuis

Inflorescence rachis multi-noded; plant without a rootstock; leaflets variable . . . . . . . . . . . 11

11. Annual; petiole 20-40 mm; flower 15-23 mm . . . . . . . . . . subsp. unguiculata var. spontanea

Perennial; petiole 50-60 mm; flower 25-31 mm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

12. Peduncle 4-15-noded, calyx teeth 5-9 mm . . . . .. . . . . . . . . . . . . . . . . . . . . . . subsp. letouzeyi

Peduncle 4-8-noded, calyx teeth 8-14 mm . . . . . . . . . . . . . . . . . . . . . . . . subsp. burundiensis

Pasquet (2001) notes that although the different perennial subspecies are morphologically, geographically and ecologically distinct they are inter-fertile and numerous intermediate specimens are found.

Vigna unguiculata subsp. unguiculata var. unguiculata

Reference to a published description: CPV 191; FE 174; FTEA 643; FZ 139; LM 584, illust. 575.

Vernacular names: For the four most important cultigens there are numerous vernacular names but these include for cv. gr. unguiculata (L.) Westphal (cowpea, African bean, black-eye bean, black-eye pea, southern pea, China pea, kaffir pea, marble pea [English], kafferboontjie [Afrikaans], haricot dolique and dolique de Chine [French] and many more local names), cv. gr. biflora (L,) Westphal (catjang, catjang cowpea and many local names), cv. gr. sesquipedalis (L.) Westphal (yard-long bean, asparagus bean, snake bean [English], dolique asperge [French]. In Somalia it is known as Salbuko, salbuko-deghell as well as catjang. It is also known in Madagascar as Antaka, Avokondrana, Lozy, Mahalaindolo, Voahimba, Voanemba, and Voatsirokonangatra.

Habit and life span: Annual or perennial, climbing or trailing, herb.

Flower colour: White to purple.

Habitat: Cultivated.

Altitude: Depending on cultivation.

Distribution: Cowpea is widely cultivated throughout the tropical and semi-tropical regions of Africa, America and Asia (Ehlers and Hall, 1997, FAOSTAT, 2002).

Phenology: Throughput the year.

Uses: Cultivated for edible beans cowpea. The cultivated forms are:

Vigna unguiculata subsp. unguiculata var. unguiculata cultivar group Sesquipedalis (L.) Westphal, Pulses in Ethiopia: 214 (1974).

Vigna unguiculata subsp. unguiculata var. unguiculata cultivar group Melanophthalmus (DC.) Pasquet, Agronomie 18: 61-70 (1998).

Vigna unguiculata subsp. unguiculata var. unguiculata cultivar group Unguiculata (L.) Westphal, Pulses in Ethiopia: 213 (1974).

Vigna unguiculata subsp. unguiculata var. unguiculata cultivar group Biflora (L.) Westphal, Pulses in Ethiopia: 214 (1974).

Conservation notes: This variety by comparison with the other subspecific taxa is well represented in ex situ collections from throughout its range; therefore further collection is not a priority.

Taxonomic notes: Pasquet (2001) notes that Mithen 55 is intermediate with subsp. tenuis.

Vigna unguiculata subsp. unguiculata var. spontanea (Schweinf.) Pasquet, Bull. Jard. Bot. Nat. Belg. 62: 155 (1993).

Reference to a published description: FZ 140.

Vernacular names: None known.

Habit and life span: Annual or rarely perennial.

Flower colour: White, greenish, yellow or lilac-purple.

Habitat: Savannah, especially disturbed areas, often as a weed.

Associated species: Unknown.

Altitude: 0 – 1850m.

Distribution:

CEAF: BUR, CHA(!), CON, ZAI.

EAF: KEN, TAN.

NEAF: ERI, SUD.

SAF: NAM, ZAF.

WAF: CMN, NGA, NGR, SEN.

ZAMB: ANG, BOT, MLW, MOZ, ZAM, ZIM.

Uses: None known.

Conservation Notes: This variety by comparison with the other subspecific taxa is well represented in ex situ collections from throughout its range; therefore further collection is not a priority.

Vigna unguiculata subsp. baoulensis (A. Chev.) Pasquet, Bull. Jard. Bot. Nat. Belg. 62: 158 (1993) *#.

Vernacular names: None known.

Habit and life span: Perennial.

Flower colour: Purple.

Habitat: Disturbed areas.

Associated species: Unknown.

Altitude: 80-1250m.

Distribution:

WAF: CMN, GHA, IVO, LBR, NGA, SIE(!), TOG.

ZAMB: ZAM.

Phenology: Unknown.

Uses: None known.

Conservation Notes: V. unguiculata subsp. baoulensis is restricted to West Africa (with one Zambian collection), it is relatively well represented in ex situ collections; however, further collection is required but it is not such a high priority as for subsp. aduensis and burundiensis.

Vigna unguiculata subsp. letouzeyi Pasquet, Bull. Jard. Bot. Nat. Belg. 62: 159 (1993) *#.

Reference to a published description: .

Vernacular names: None known.

Habit and life span: Perennial.

Flower colour: Purple.

Habitat: Disturbed areas.

Associated species: Unknown.

Altitude: 320-800m.

Distribution:

CEAF: CAF, GAB(!), ZAI.

WAF: CMN.

Phenology: 300-800.

Uses: None known.

Conservation Notes: This subspecies by comparison with the other subspecific taxa is well represented in ex situ collections from throughout its range; therefore further collection is not a priority.

Vigna unguiculata subsp. burundiensis Pasquet, Bull. Jard. Bot. Nat. Belg. 62: 162 (1993) *#.

Reference to a published description: .

Vernacular names: None known.

Habit and life span: Perennial.

Flower colour: Purple.

Habitat: Disturbed areas.

Associated species: Unknown.

Altitude: 1800-1900m.

Distribution:

CEAF: BUR, RWA(!), ZAI(!).

EAF: KEN(!), UGA(!).

Phenology: Unknown.

Uses: None known.

Conservation Notes: V. unguiculata subsp. burundiensis is recently described thus less well known, in comparison with the other subspecific taxa it is geographically restricted and represented by a single ex situ collection; therefore further collection is a priority from throughout the range given by Pasquet (1993). The lack of material and restricted distribution indicates that this subspecies deserves a higher conservation priority; an IUCN Red List Category of Vulnerable is appropriate.

Vigna unguiculata subsp. pubescens (R.Wilczek) Pasquet, Bull. Jard. Bot. Nat. Belg. 62: 164 (1993).

Reference to a published description: FCBR 386; FTEA 646; FZ 141.

Vernacular names:

SUD: Najok.

MOZ: Niembaoda

TAN: Lukundembala, Kundimbala.

Habit and life span: Perennial, climbing, herb.

Flower colour: White, greenish, yellow or lilac-purple.

Habitat: Grasslands, coastal thickets, rocky outcrops, roadsides, savannas and fallow fields, usually near water.

Associated species: Unknown.

Altitude: 0–1550m.

Distribution:

CEAF: BUR, ZAI.

EAF: KEN, TAN, UGA.

NEAF: SUD.

SAF: NAM, ZAF.

WAF: GHA, NGA.

ZAMB: MLW, MOZ, ZIM.

Phenology: October to December.

Uses: None known.

Vigna unguiculata subsp. dekindtiana (Harms) Verdc., Kew Bull. 24: 544 (1970).

Reference to a published description: FE 174; FS 436; FTEA 644, illust. 645; FZ 141, illust. 142.

Vernacular names:

ANG: Kakundi-Kombambi

CMN: Mebbiladdi

ZAI: Kasema Pori, Yarkame, Abakpanvua, Manyasa na Nzamba.

GHA: Benet, Kusasi, Goya Kusasi

KEN: Chani, Chesuwaucha, MkundeMLWta, Mkundembala

MOZ: Nchanchin nhyemba

NAM: Gani

NGA: Akadi; Akedi aja, Akedi nkulunku , Gayan gayan, Kgbamaje, Wake and Wakengizo

TAN: Enandala, Kibenda benda, Shilishashiliwa,

UGA: Amaret, Kindiru, Omugambe, Karimojoij bean

Habit and life span: Wild or cultivated, prostrate or climbing.

Flower colour: White, greenish, yellow or lilac-purple.

Habitat: Roadsides, open woodlands, grasslands (especially if burnt seasonally), various savannas, swamps, cultivated fields, riversides, riverine forests, littoral zones, etc.

Associated species: Acacia, Adansonia, Brachystegia, Combretum, Digitaria, Eragrostis, Euphorbia, Imperata, Terminalia, Sporobolus, etc.

Altitude: 1-2800m.

Distribution:

CEAF: BUR(!), CAF, CHA, CON, GAB(!), GGI, ZAI.

EAF: KEN, TAN, UGA.

NEAF: ERI, ETH, SEN, SIE, SOM(!), SUD.

SAF: NAM, SWZ, ZAF.

WAF: BEN, BKN, CMN, GAM, GHA, GNB, GUI, IVO, MLI, NGA, NGR, SEN, SIE.

ZAMB: ANG, BOT, MLW, MOZ, ZAM, ZIM.

Phenology: Depends on floristic region.

Uses: The roots are roasted and eaten by the Kung of Namibia and used to dye leather in Nigeria (Dalziel, 1937). In Ghana the leaves are eaten in stews and the seeds are used to make Goya Kusasi. The leaves are also eaten as a vegetable in Tanzania and Kenya, more so in times of famine. The seeds are collected and used as food in Uganda.

Taxonomic Notes: Pasquet (2001) notes that lowland specimens from eastern Angola and Zambia, although pyrophytic, show more nodes per inflorescence, smaller flowers, with a shorter keel beak and higher ovule number than is typical, which may indicate that they are intermediates between subsp. dekindtiana and subsp. unguiculata var. spontanea.

Conservation Notes: This subspecies, by comparison with the other subspecific taxa, is well represented in ex situ collections from throughout its range; therefore further collection is not a priority.

Vigna unguiculata subsp. tenuis (E.Mey.) Maréchal, Mascherpa and Stainier, Taxon 27: 200 (1978).

Reference to a published description: CPV 195; FZ 143.

Vernacular names: None known.

Habit and life span: Perennial with rootstock.

Flower colour: Pink to purple.

Habitat: Miombo woodland, grassland, and sandy places near coast.

Associated species: Unknown.

Altitude: 1– 1550m.

Distribution:

EAF: KEN.

SAF: ZAF.

ZAMB: MLW, MOZ, ZAM, ZIM.

Phenology: Year round.

Uses: None known.

Taxonomic Notes: Pasquet (2001) notes that Mozambique specimens, especially coastal specimens are quite different and could be intermediates with subsp. unguiculata. The inflorescence is often up to 3-noded, flowers are larger and ovule numbers is markedly higher, (13-)14-17-ovuled as compared to 12-15(-16)- ovuled in other Flora Zambesiaca countries.

Conservation Notes: This subspecies, in comparison to other subspecific taxa, is well represented in ex situ collections from throughout its range; therefore further collection is not a priority.

Vigna unguiculata subsp. stenophylla (Harv.) Maréchal, Mascherpa and Stainier, Taxon 27: 200 (1978).

Reference to a published description: CPV 196; FZ 144.

Vernacular names: None known.

Habit and life span: Perennial with rootstock.

Flower colour: Pink to purple.

Habitat: Kalahari sands in FZ region.

Associated species: Terminalia sericea.

Altitude: 1-2350m.

Distribution:

CEAF: BUR

SAF: NAM, SWZ, ZAF.

ZAMB: BOT, MOZ, ZAM, ZIM(!).

Phenology: Unknown.

Uses: None known.

Conservation Notes: This subspecies by comparison with other subspecific taxa is well represented in ex situ collections from throughout its range; therefore further collection is not a priority.

Taxonomic Notes: Pasquet (2001) suggests that three groups might be distinguished within subspecies stenophylla with intermediate specimens between them in the areas where their distributions overlap. The first group would include stout specimens from dry areas of Namibia, Botswana and western parts of the former Transvaal, in which the plants are scabrous or poorly pubescent with scabrous pods. The second group would include specimens from eastern parts of the former Transvaal and Cape Province of South Africa with stout and pubescent plants often with pubescent pods. The third group would include specimens from the Transvaal where the plants are more slender and possess linear leaflets and scabrous pods.

Vigna unguiculata subsp. alba (G. Don.) Pasquet, Kew Bull. 48: 805 (1993)

Reference to a published description: FCBR; FTEA; FZ.

Vernacular names: None known.

Habit and life span: Perennial.

Flower colour: White?.

Habitat: Disturbed grassland and forest margin.

Associated species: Unknown.

Altitude: 1-1700m.

Distribution:

CEAF: CON, GAB(!), GGI, ZAI.

EAF: TAN.

ZAMB: ANG, ZIM.

Phenology: Unknown.

Uses: None known.

Vigna unguiculata subsp. pawekiae Pasquet, Kew Bull. 48: 806 (1993).

Reference to a published description: FCBR 387; FTEA 646; FZ 141.

Vernacular names:

ZAI: Kulu, Ndekona mongasa

ETH: Turina

Habit and life span: Wild, climbing perennial.

Flower colour: White, greenish, yellow or lilac-purple.

Habitat: Tree and palm savannas, swampy areas, roadsides, gallery forests, grasslands and fallow fields.

Associated species: Unknown.

Altitude: 1–2700 (-3650 in Kenya)m.

Distribution:

CEAF: BUR, GGI, ZAI.

EAF: KEN, TAN(!), UGA.

NEAF: ERI, ETH.

WAF: CMN, NGA, SIE.

ZAMB: ANG, BOT, MLW, MOZ, ZAM, ZIM.

Phenology: Unknown.

Uses: None known.

Vigna unguiculata subsp. aduensis Pasquet, Kew Bull. 52: 840 (1997) *#.

Reference to a published description: FCBR; FTEA; FZ.

Vernacular names: None known.

Habit and life span: Wild, climbing perennial.

Flower colour: Purple.

Habitat: Disturbed areas.

Associated species: Unknown.

Altitude: 1200-2900m.

Distribution: obvious

NEAF: ETH.

Phenology: Unknown.

Uses: None known.

Conservation Notes: V. unguiculata subsp. aduensis is the most recently described subspecies and as an Ethiopian endemic is the most geographically restricted subspecies. There are no ex situ collections, and only a few herbarium specimens are known; therefore further collection is a priority to help establish the true range of the taxon and provide conservation of an important crop wild relative. The lack of material and restricted distribution indicates that this subspecies deserves a higher conservation priority; an IUCN Red List Category of Endangered is appropriate.