Rungia klossii (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Rungia klossii S. Moore

Protologue: Trans. Linn. Soc., Bot. 9: 135 (1916).

Family: Acanthaceae

Chromosome number: 2n= unknown

Vernacular names

• Rungia (En)
• Papua New Guinea: kenkaba, tani, moku, ainbe.

Origin and geographic distribution

R. klossii has been domesticated in the highlands of New Guinea and is probably a native of the same area. It is not known outside Papua New Guinea and Irian Jaya (Indonesia) where wild and cultivated forms occur together.

Uses

The leaves are used as a pot herb, often cooked together with the leaves of highland "pitpit" (Setaria palmifolia (Koenig) Stapf). They are sometimes eaten raw. Wild forms growing in the forest are used by hunting parties and collected in times of scarcity.

Production and international trade

Rungia is one of the most popular greens in the highlands of New Guinea, and is very common in highland markets. No production statistics are available.

Properties

Per 100 g edible portion, rungia leaves contain: water 87.9 g, protein 2.5-5 g, and Ca 272 mg. The energy value is 138 kJ/100 g.

Botany

• Perennial shrub, up to about 0.8 m tall.
• Stem branched, internodes pubescent along 2 opposite lines.
• Leaves opposite; petiole 1-3 mm long; leaf-blade elliptical-lanceolate, 2-4 cm × 1-2.5 cm, basally rounded, apically shortly attenuate, apex obtuse, sparsely pubescent, especially on nerves underneath, dark green when fresh and yellowish along nerves, in a wider zone along midnerve.
• Inflorescences terminal and axillary spikes, 2-4 cm × 1.5 cm; bracts 4-ranked, 2 neighbouring ranks fertile, 2 sterile, elliptical with conspicuous, often lightly purplish, scarious, ciliate margins, otherwise green, fertile ones pubescent, sterile ones glabrous or very sparsely pubescent; bracteoles as bracts but smaller; calyx 5-lobed, lobes linear-lanceolate, 5.5 mm; corolla white to pale purple, bilabiate with tubular part about 5 mm long, lower lip about 10 mm × 10 mm and shortly 3-lobed, upper lip 5 mm × 5 mm and bifid; stamens 2, anthers bithecous, upper theca muticous below, lower theca shortly spurred.

When grown from cuttings, rungia develops into a bushy shrub with good ground cover. Growth is rather slow during the first few months, but once it matures it recovers rapidly from a plucking or pruning round.

Ecology

Rungia mainly grows in the cool climates of the highlands. Although it can be found at sea-level and as high as 2700 m, it is hardly important outside the altitudinal range of 1200-2000 m. It seems to grow well under shade as well as in the open, and prefers fertile, well-drained soils.

Agronomy

Rungia is propagated from semi-hardwood cuttings, 15-20 cm long. It is usually planted together with other food plants in sweet potato gardens, forest mixed-crop gardens or kitchen gardens. In pure stands it is grown at a spacing of about 50 cm × 50 cm, and needs a lot of weeding because it grows slowly. A mulch of coffee pulp has been reported to increase yields considerably.

No serious diseases or pests have been recorded on the crop in Papua New Guinea. Shoot tips can be harvested 2-4 months after planting and thereafter at 1-2 monthly intervals for 2 years. Harvested tips are usually small. Yields of 1-2 kg/plant per year can be obtained, or 20-40 t/ha per year at a density of 20 000 plants/ha.

Genetic resources and breeding

Considerable variation can be observed in wild and cultivated materials. No germplasm collections are being maintained, and no breeding activities are being carried out.

Prospects

Very limited information is available on rungia. If it does not receive research attention in order to determine its potential, it is likely to decrease in importance, being replaced by the more productive introduced vegetables.

Literature

• Bourke, R.M., 1981. Some little-known crops of Papua New Guinea. Science in New Guinea 8(3): 164-170.
• Bourke, R.M. & D'Souza, E., 1982. Intensification of subsistence agriculture on the Nembi Plateau: preliminary results. In: Proceedings of the Second Papua New Guinea Food Crops Conference, July 14-18, 1980, Goroka. Department of Primary Industry, Port Moresby, Papua New Guinea. pp. 202-207.
• Powell, J.M., Kulunga, A., Moge, R., Pono, C., Zimike, F. & Golson, J., 1975. The crops grown for food. Agricultural traditions of the Mount Hagen area. University of Papua New Guinea Occasional Paper No 12. pp. 15-32.
• Sillitoe, P., 1983. Roots of the earth: crops in the highlands of Papua New Guinea. Manchester University Press, United Kingdom. pp. 60-62.
• Twohig, A. (Editor), 1986. Crops: traditional vegetables. Liklik buk, a sourcebook for development workers in Papua New Guinea. Liklik Buk Information Centre, University of Technology, Lae, Papua New Guinea. pp. 77-78.

Authors

• A.M. Gurnah