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Amaranthus graecizans L.

Protologue
Sp. pl. 2: 990 (1753).
Family
Amaranthaceae
Chromosome number
2n = 32, 34
Synonyms
Amaranthus angustifolius Lam. (1783), Amaranthus silvestris Vill. (1807), Amaranthus thellungianus Nevski (1937).
Vernacular names
Wild amaranth, prostrate amaranth, spreading pigweed (En). Amarante sauvage, amarante sylvestre, amarante africaine (Fr). Tristes, amaranto, bredo (Po). Mchicha (Sw).
Origin and geographic distribution
Amaranthus graecizans occurs scattered throughout tropical Africa, where it has been recorded for many countries. It is also distributed in southern Europe and in tropical and subtropical Asia, and has been introduced to the United States. It is especially popular as a vegetable in parts of Kenya, Uganda, Tanzania, Malawi and elsewhere in southern Africa, and is sometimes a protected weed in backyards and home gardens. It is locally cultivated on a small scale in home gardens e.g. by the Acholi people in Nebbi, Uganda, and in Tanzania for market sale to people of Indian origin.
Uses
The main use of Amaranthus graecizans is as a cooked leaf vegetable. In many countries it is collected as a potherb from the wild. Especially older people appreciate the slightly bitter taste. A major drawback is that the leaves are small and collection takes time. Because of the many flowers, people will not cook the whole shoot but they pick the individual leaves, which is one reason why this amaranth has a low market value. In some regions it is eaten mixed with other leaf vegetables collected from the wild, e.g. by the Okiek people in Western Kenya, who mix it commonly with Solanum or Rumex species and Urtica massaica Mildbr.
Amaranthus graecizans is used as a fodder for livestock. In Mauritania the seed is baked into thin cakes, while in the western United States it is ground into flour. Like other wild amaranths, whole plants of Amaranthus graecizans are used in East and West Africa to manufacture a local salt. For this purpose, the plants are dried and burned to ashes, the filtrate is evaporated and the residue used as a substitute for common salt. In Uganda, the leaves are chewed and the liquid swallowed to treat tonsillitis. In Senegal, the leaves are used as an anthelmintic.
Production and international trade
Amaranthus graecizans is occasionally sold at markets as a low-value vegetable, but there are no records on production and trade.
Properties
The composition of Amaranthus graecizans leaves is comparable to that of other amaranths. The average composition of amaranth leaves per 100 g edible portion is: water 84.0 g, energy 176 kJ (42 kcal), protein 4.6 g, fat 0.2 g, carbohydrate 8.3 g, fibre 1.8 g, Ca 410 mg, P 103 mg, Fe 8.9 mg, β-carotene 5716 μg, thiamin 0.05 mg, riboflavin 0.42 mg, niacin 1.2 mg, ascorbic acid 64 mg (Leung, W.-T.W., Busson, F. & Jardin, C., 1968). The dry matter content is high (9–22%), as well as the micronutrient content, especially calcium, iron, carotene, folate and vitamin C, if compared to other leaf vegetables. The calcium is partly insoluble and not taken up in the digestive tract, as it is bound to oxalate. The bioavailability of iron is 6–12%. The leaves become soft after 5–10 minutes cooking in slightly salted water. The nitrate (mostly in the stems) and oxalate levels are high, but cooking in ample water removes most of these toxic components. The presence of hydrocyanic acid and oxalic acid makes it less suitable for fresh consumption by humans and as fodder for animals.
Adulterations and substitutes
In dishes with green leafy vegetables or potherbs, Amaranthus graecizans may be replaced by any other vegetable amaranth.
Description
Small annual herb up to 45(–70) cm tall, prostrate or decumbent, often strongly branched from the base and usually also above; stem and branches slender to stout, angular, glabrous or thinly furnished with short to long, crisped, multicellular hairs. Leaves arranged spirally, simple, without stipules; petiole 3–5 cm long, sometimes longer than lamina; lamina broadly ovate or rhombic-ovate to narrowly linear-lanceolate, 0.5–5.5 cm Χ 0.2–3 cm, cuneate to long-attenuate at base, acute to blunt or obscurely retuse at apex, entire, glabrous or with a few short glandular hairs on the lower surface of the venation. Inflorescence an axillary cluster, with male and female flowers intermixed but male flowers most frequent in upper clusters; bracts up to 2 mm long, with short or long awn. Flowers unisexual, subsessile, with 3 tepals up to 2 mm long, having a short awn; male flowers with 3 stamens; female flowers with superior, 1-celled ovary crowned by 3 stigmas. Fruit a globose to shortly ovoid capsule up to 2.5 mm long, with a very short beak below the stigmas, usually strongly wrinkled, usually circumscissile, 1-seeded. Seed compressed, 1–1.5 mm long, faintly reticulate, black.
Other botanical information
Amaranthus comprises about 70 species, of which about 40 are native to the Americas. It counts at least 17 species with edible leaves. Amaranthus graecizans resembles Amaranthus thunbergii Moq., but may be distinguished by its branched habit, glabrous stems or furnished with few hairs, and by the short awn of the tepals. Amaranthus sparganiocephalus Thell. is another weedy amaranth locally collected as a leafy vegetable; it differs in its globular head-like inflorescences and fruits arranged in a star-shaped pattern.
Amaranthus graecizans is variable. Three subspecies are distinguished: subsp. graecizans, with leaves oblong to linear-lanceolate (at least 2.5 times as long as broad) and short tepal awns; subsp. silvestris (Vill.) Brenan, with leaves broadly ovate to rhombic-ovate or elliptical-ovate (less than 2 times as long as broad) and short tepal awns; and subsp. thellungianus (Nevski) Gusev, with leaves rhombic-spatulate to narrowly linear-lanceolate and long tepal awns. These subspecies are sympatric in some regions, and then intermediate forms may be common, e.g. in Ethiopia. Subsp. graecizans is most common in West Africa, subsp. silvestris in East Africa, and subsp. thellungianus mainly occurs in southern Africa.
Growth and development
Emergence of the seedling takes place 3–5 days after sowing. The vegetative development is fast. The genus Amaranthus is characterized by the C4-cycle photosynthetic pathway, which means a high photosynthesis at high temperature and radiation. Flowering may start 4–8 weeks after sowing. The growth of new shoots continues after the start of flowering. Pollination is effected by wind but the abundant pollen production, especially in the upper part of flowering plants, causes a high rate of self-pollination. Seeds mature after 1–2 months.
Ecology
Amaranths in general perform best on fertile, well-drained soils with a loose structure, but Amaranthus graecizans also grows well on poor soils. It is very resistant to adverse climate and soil conditions. It is found on waste or cultivated ground, forest edges and grassland, mostly in arid areas but also in marshy or flooded land, from sea level to 2400 m, in regions with an annual rainfall of 600–1800 mm. If there is less rainfall, it is only found during the rainy season. It grows well in somewhat shaded conditions.
Management
Cultivation is relatively easy; the same technology as for Amaranthus blitum L. may be applied. Where Amaranthus graecizans is appreciated as a vegetable, selective weeding may be applied by removal of all other weeds. Water shortage causes early flowering, which reduces yield and market quality. Amaranth is a very high consumer of minerals. On poor soils only modest crops are produced.
Propagation and planting
In the wild and in home gardens the seed of fruiting plants is scattered and gives rise to new plants. Dormant seed remains viable in the soil for several years. It germinates at the surface or in the upper 3 cm of the soil. Seeds can be obtained by rubbing mature infructescences. The seeds can be sown directly, broadcast or in rows with 15–20 cm between the rows, with a seed rate of 2–5 g/m2. Another cultivation method is sowing in a seedbed (nursery) at a seed rate of 3–10 g/m2 and transplanting after 2–3 weeks. A plant density of 100–200 plants/m2 can be practised for a once-over harvest, whereas 25 plants/m2 is appropriate for repeated cuttings.
Diseases and pests
Although information is limited, Amaranthus graecizans seems to be very tough and resistant to pests and diseases. It is a host plant of Verticillium fungi, which may cause damage to tomato.
Harvesting
Young plants and young tender shoots are picked as a vegetable. When whole plants are harvested they are uprooted after 4–5 weeks. When plants are harvested several times, it is advised to pick individual leaves when seeds have started maturing because stray seeds in prepared food feel like sand in the mouth.
Handling after harvest
If collected for the market, shoots and leaves are often sprinkled with water to keep a fresh appearance.
Genetic resources
Amaranthus graecizans is widespread and usually occurs in disturbed habitats, and thus does not seem to be threatened by genetic erosion. The genetic variation in this polymorphic species seems considerable.
Prospects
Amaranthus graecizans is a tasty and nutritious traditional wild vegetable, in which there is decreasing interest. The prospects for domestication and cultivation as vegetable are poor because it would have to compete with higher yielding amaranths, such as the commonly cultivated Amaranthus cruentus L., Amaranthus blitum L., Amaranthus dubius Mart. ex Thell. and Amaranthus tricolor L. In breeding of cultivated amaranths, Amaranthus graecizans might be used as genitor of resistance genes.
Major references
• Burkill, H.M., 1985. The useful plants of West Tropical Africa. 2nd Edition. Volume 1, Families A–D. Royal Botanic Gardens, Kew, United Kingdom. 960 pp.
• Maundu, P.M., Ngugi, G.W. & Kabuye, C.H.S., 1999. Traditional food plants of Kenya. Kenya Resource Centre for Indigenous Knowledge (KENRIK), Nairobi, Kenya. 270 pp.
• Schippers, R.R., 2000. African indigenous vegetables. An overview of the cultivated species. Natural Resources Institute/ACP-EU Technical Centre for Agricultural and Rural Cooperation, Chatham, United Kingdom. 214 pp.
• Townsend, C.C., 1985. Amaranthaceae. In: Polhill, R.M. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. 136 pp.
• Townsend, C.C., 1988. Amaranthaceae. In: Launert, E. (Editor). Flora Zambesiaca. Volume 9, part 1. Flora Zambesiaca Managing Committee, London, United Kingdom. pp. 28–133.
• Townsend, C.C., 2000. Amaranthaceae. In: Edwards, S., Mesfin Tadesse, Demissew Sebsebe & Hedberg, I. (Editors). Flora of Ethiopia and Eritrea. Volume 2, part 1. Magnoliaceae to Flacourtiaceae. The National Herbarium, Addis Ababa University, Addis Ababa, Ethiopia and Department of Systematic Botany, Uppsala University, Uppsala, Sweden. pp. 299–335.
Other references
• Baquar, S.R. & Olusi, O.O., 1988. Cytomorphological and phylogenetic studies of the genus Amaranthus from Nigeria. Kromosomo (Tokyo) 2(51–52): 1665–1674.
• Grubben, G.J.H., 1993. Amaranthus L. In: Siemonsma, J.S. & Kasem Piluek (Editors). Plant Resources of South-East Asia No 8. Vegetables. Pudoc Scientific Publishers, Wageningen, Netherlands. pp. 82–86.
• Holland, B., Unwin, I.D. & Buss, D.H., 1991. Vegetables, herbs and spices. The fifth supplement to McCance & Widdowson’s The Composition of Foods. 4th Edition. Royal Society of Chemistry, Cambridge, United Kingdom. 163 pp.
• Katende, A.B., Ssegawa, P. & Birnie, A., 1999. Wild food plants and mushrooms of Uganda. Technical Handbook No 19. Regional Land Management Unit/SIDA, Nairobi, Kenya. 490 pp.
• Leung, W.-T.W., Busson, F. & Jardin, C., 1968. Food composition table for use in Africa. FAO, Rome, Italy. 306 pp.
• Madhusoodanan, K.J. & Pal, M., 1981. Intraspecific aneuploidy in Amaranthus graecizans. Botanical Journal of the Linnean Society 82: 61–68.
• Marshall, F., 2001. Agriculture and use of wild and weedy greens by the Piik ap Oom Okiek of Kenya. Economic Botany 55(1): 32–46.
• Sammour, R.H., Hamoud, M.A., Alla, S.A.A. & Abd-Alla, S.A., 1993. Electrophoretic variations in Amaranthus. Botanical Bulletin of Academia Sinica 34(1): 37–42.
Sources of illustration
• Hegi, G., 1979. Illustrierte Flora von Mittel-europa. 2nd Edition. Pteridophyta, Spermatophyta. Band 3. Angiospermae, Dicotyledones 1. Verlag Paul Parey, Berlin, Germany. pp. 453–1234.
• Townsend, C.C., 1985. Amaranthaceae. In: Polhill, R.M. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. 136 pp.
Author(s)
• P.M. Maundu
c/o World Agroforestry Centre, P.O. Box 30677, Nairobi, Kenya
• G.J.H. Grubben
Prins Hendriklaan 24, 1401 AT Bussum, Netherlands


Editors
• G.J.H. Grubben
Prins Hendriklaan 24, 1401 AT Bussum, Netherlands
• O.A. Denton
National Horticultural Research Institute, P.M.B. 5432, Idi-Ishin, Ibadan, Nigeria
Associate Editors
• C.-M. Messiaen
Bat. B 3, Rιsidence La Guirlande, 75, rue de Fontcarrade, 34070 Montpellier, France
• R.R. Schippers
De Boeier 7, 3742 GD Baarn, Netherlands
General editors
• R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
• L.P.A. Oyen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
Illustrator
• Iskak Syamsudin
PROSEA Network Office, P.O. Box 332, Bogor 16122, Indonesia
Photo Editor
• E. Boer
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article:
Maundu, P.M. & Grubben, G.J.H., 2004. Amaranthus graecizans L. In: Grubben, G.J.H. & Denton, O.A. (Editors). PROTA 2: Vegetables/Lιgumes. [CD-Rom]. PROTA, Wageningen, Netherlands.
Distribution Map wild and planted


1, plant habit; 2, fruit; 3, seed.
Redrawn and adapted by Iskak Syamsudin



flowering plant