Difference between revisions of "Portulaca quadrifida (PROTA)"

Latest revision as of 10:37, 23 March 2015

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Vegetable
Medicinal
Ornamental
Forage / feed
Food security
Climate change

Portulaca quadrifida L.

Protologue: Mant. pl. 1: 73 (1767).

Family: Portulacaceae

Chromosome number: 2n = 48

Synonyms

Vernacular names

Single-flowered purslane, small-leaved purslane, ten o’clock plant, chickenweed (En). Pourpier (Fr). Beldroega (Po). Kinyorwe (Sw).

Origin and geographic distribution

Portulaca quadrifida is widely distributed in Africa and tropical Asia, and it has been introduced into the warmer areas of the Americas. In Africa it is found in all countries, usually as a weed, rarely cultivated (e.g. in DR Congo and Rwanda).

Uses

The leaves and young shoots of Portulaca quadrifida are collected from the wild and are eaten raw. They have a mild pleasant flavour and are frequently used in salads. They are also consumed as a cooked vegetable. In India boiled leaves are mixed with sorghum or pearl millet flour in preparing a kind of bread. Plants are a good feed for pigs, chicken and other birds. Large types are sometimes planted as an ornamental (e.g. in Rwanda) or as a soil binder to prevent erosion (e.g. in Kenya). Medicinally Portulaca quadrifida is used less widely but has similar medicinal applications as Portulaca oleracea L. The general uses are as a diuretic, to treat rheumatism and gynaecological diseases, as a sedative, analgesic and cardiotonic, to treat fever, disorders of the urinary tract, worm diseases, as a tonic and choleretic, to treat dysentery, and to apply externally to ulcers, eczema and dermatitis.

Properties

The nutritional composition of Portulaca quadrifida is probably comparable to Portulaca oleracea. Portulaca quadrifida may contain oxalates in toxic quantities, which may cause death in livestock. In some soils it also tends to accumulate nitrates and thus should be consumed in moderate quantities.

Botany

Prostrate, mat-forming annual or short-lived perennial herb with much-branched, spreading, articulated, fleshy stems up to 30 cm long or longer, rooting freely from the nodes, often flushed reddish; nodes with a dense whorl of whitish hairs. Leaves opposite, simple, sessile, narrowly elliptical to ovate, 0.5–1.5 cm × 1–4 mm, apex obtuse to subacute, smooth, veins distinct. Flowers solitary at the tips of short lateral branches, surrounded by 4 involucral leaves and copious hairs, bisexual; sepals 2, ovate, 3(–6) mm long; petals 4, obovate, 3.5–10 mm × 4 mm, usually yellow (rarely pinkish); stamens 7–16, arranged in 1 whorl; ovary half-inferior, style usually with 4 arms. Fruit an obovoid capsule 2–3.5 mm long, dehiscing near the base leaving only a very thin persistent rim, many-seeded. Seeds semi-orbicular in outline, c. 1 mm in diameter, dull grey.

Portulaca comprises about 150 species, of which about 30 occur in tropical Africa, but opinions on species delimitation differ considerably. Particularly the group of species with alternate leaves is taxonomically difficult. Portulaca quadrifida is rather unique with its mat-forming habit, but it is very variable, particularly in stamen number and flower size. In Africa only Portulaca pilosa L. has a similar habit, but it has alternate leaves, 5 petals and more numerous stamens.

Like Amaranthus, Portulaca is characterized by the C₄-cycle photosynthetic pathway, which means a high rate of photosynthesis at high light intensity and temperatures. Fresh seeds need light for germination, but this requirement disappears in older seeds. Generative development seems not to be influenced by photoperiod. The flowers are said to open promptly at 10 a.m., hence the English name ‘ten o’clock plant’. Seeds of Portulaca quadrifida are easily spread by wind, water, with crop seeds or through bird droppings, and as a weed it is difficult to control because it also easily propagates from small fragments.

Description

Other botanical information

Growth and development

Ecology

Portulaca quadrifida is found in the wild on bare patches and among rocks, on sandy or stony soils, from sea-level up to 2000 m altitude. It is often involuntarily introduced by the agency of man and readily occupies newly disturbed areas, compost and rubbish heaps and fields. In some African languages it is called ‘Lord of the rubbish heap’. It is tolerant of a wide range of soils but prefers sand or sandy loams.

Harvesting

Genetic resources

The wide distribution and large variation of Portulaca quadrifida points to great genetic flexibility that rapidly permits adaptation to new environments.

Prospects

Portulaca quadrifida will remain a minor vegetable, only of importance when other vegetables are scarce. Its nutritional composition and medicinal properties deserve further investigation. Cultivation can not be recommended because it also can behave as an aggressive weed.

Major references

• Burkill, H.M., 1997. The useful plants of West Tropical Africa. 2nd Edition. Volume 4, Families M–R. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 969 pp.

• Gilbert, M.G. & Phillips, S.M., 2000. A review of the opposite-leaved species of Portulaca in Africa and Arabia. Kew Bulletin 55: 769–802.

• 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.

• Phillips, S.M., 2002. Portulacaceae. In: Beentje, H.J. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. 40 pp.

• Susiarti, S., 1993. Portulaca L. In: Siemonsma, J.S. & Kasem Piluek (Editors). Plant Resources of South-East Asia No 8. Vegetables. Pudoc Scientific Publishers, Wageningen, Netherlands. pp. 227–229.

Other references

• Freedman, R., 1996. Famine foods. [Internet] Purdue University, West Lafayette, Indiana, United States. http://www.hort.purdue.edu/newcrop/FamineFoods/ff_home.html. February 2004.

• Gilbert, M.G., 2000. Portulacaceae. 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. 249–258.

• Hauman, L., 1951. Portulacaceae. In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 2. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. pp. 118–127.

• Kokwaro, J.O., 1993. Medicinal plants of East Africa. 2nd Edition. Kenya Literature Bureau, Nairobi, Kenya. 401 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.

• Westphal, E., 1975. Agricultural systems in Ethiopia. Agricultural Research Reports 826. Centre for Agricultural Publishing and Documentation, Wageningen, Netherlands. 278 pp.

• Wild, H., 1961. Portulacaceae. In: Exell, A.W. & Wild, H. (Editors). Flora Zambesiaca. Volume 1, part 2. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. pp. 362–372.

Author(s)

• P.C.M. Jansen

PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Jansen, P.C.M., 2004. Portulaca quadrifida L. [Internet] Record from PROTA4U. Grubben, G.J.H. & Denton, O.A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. <http://www.prota4u.org/search.asp>.

Accessed 22 December 2024.

• See the Prota4U database.