Common name: Bignay

Bignay is a fruit and ornamental tree native to a wide geographic area extending from the Himalayan foothills in India, south to Sri Lanka, and east through Southeast Asia to northern Australia.

It is a small tree on open sites, typically 5 to 10 m (15 to 30 ft) tall, with a single trunk supporting a densely branched rounded crown. 

The leaves are oblong, up to 15 cm (6 in) long, dark glossy green and alternately arranged along the ends of the branches. They remain on the tree throughout the year.

The flowers are green-yellow, small and inconspicuous and either female or male (on separate trees). They come into bloom in spring, borne on slender flower spikes that are abundant at the tips of the branches. Flower spikes on female trees appear to have some bisexual flowers mixed in, as they bear fruit profusely even when there are no male trees nearby.

The fruit are small, round and about the size of a pea. They are in tightly packed clusters that resemble bunches of small grapes. Green when young, they ripen to red or near black, depending on the variety, with juicy purple-red pulp surrounding a single seed. They are produced in large numbers, though they ripen unevenly, with green, red and purple fruit usually present in the same cluster.

Use

The ripe fruit are mildly sourish with an agreeable flavour and are eaten fresh out-of-hand, though they are more commonly juiced. The juice is used for flavouring beverages, including cordials and syrups, or is made into jam or jelly, to which it is well-suited due to a high pectin content.

Bignay is occasionally cultivated as an ornamental for its shapely form, lush green foliage and showy clusters of colourful fruit, which attract fruit-eating birds to the garden. Its low branching structure also makes it suitable for planting as a shade or privacy screen or as a windbreak.

The leaves are sometimes used in its native range as a culinary herb to add flavour to cooked dishes, especially rice.

The bark yields a fibre, which has traditional use as a fibre for weaving into rope.

Climate

Bignay grows naturally in moderately humid to humid subtropical and tropical lowland to mid-elevation climates, generally in frost-free areas with annual lows of 18 to 25°C, annual highs of 27 to 35°C, annual rainfall of 1200 to 3000 mm and a dry season of 5 months or less. 

Bignay trees may fail to thrive in areas where the average low of the coldest month is below 12°C (54°F).

Growing

New plants can be grown from seed, cuttings or using air-layering (circumposing) methods. However, the seed germinate slowly, and male and female seedlings are not easily distinguished apart. For these reasons, vegetative propagation is most often used. It produces plants that grow faster and start to flower and fruit much sooner than seedlings do, starting at around three years, compared to five years for seedlings.

Performs best on free-draining clay, loam or sand soils of a moderately acid to neutral nature, generally with a pH of 6.0 to 7.5, and on sites with full to partial sun exposure.

Problem features

Birds eat the fruit and disperse the seed. It is listed as a weed in more than one reference publication, including the Global Invasive Species Database (GISD), which records it as an invasive species in French Polynesia. The fruit juice is brightly coloured and can stain fingers and garments.

Books

• Allen, B. M. 1967, Malayan fruits : an introduction to the cultivated species, Donald Moore Press, Singapore

• Barwick, M., et al. 2004, Tropical & subtropical trees : a worldwide encyclopaedic guide, Thames and Hudson, London

• Food and Agriculture Organization of the United Nations (FAO) 1984, Food and Fruit-bearing Forest Species, 2 : Examples from Southeastern Asia, FAO Forestry Paper no 44/2, Rome

• Janick, J., & Paull, R. E. 2008, The encyclopedia of fruit & nuts, CABI Publishing, Wallingford, Oxfordshire

• Kennard, W. C. & Winters, H. F. 1960, Some fruits and nuts for the tropics, Miscellaneous Publication No. 801, U.S. Department of Agriculture, Federal Experimental Station, Mayaguez, Puerto Rico

• Lorenzi, H. 2006, Brazilian fruits & cultivated exotics (for consuming in natura), Instituto Plantarum de Estudos da Flora, Nova Odessa, San Paulo

• Martin, F. M., et al. 1987, Perennial edible fruits of the tropics : an inventory, U.S. Dept. of Agriculture (USDA), Agricultural Research Service, U.S. Government Printing Office (GPO), Washington, D.C.

• Morton, J. F. & Dowling, C. F. 1987, Fruits of warm climates, Creative Resources Systems, Winterville, North Carolina

• Page, P. E. 1984, Tropical tree fruits for Australia, Queensland Department of Primary Industries (QLD DPI), Brisbane

• Randall, R. P. 2002, A global compendium of weeds, R.G. and F.J. Richardson Press, Melbourne

• Randall, R. P. 2007, The introduced flora of Australia and its weed status, Cooperative Research Centre for Australian Weed Management, Glen Osmond, South Australia

• Seidemann, J. 2005, World spice plants: economic usage botany taxonomy, Springer-Verlag, Berlin

Articles, Journals, Reports and Working Papers

• Watson, B.J., & Moncur, M. 1985, Guideline criteria for determining survival, commercial and best mean minimum July temperatures for various tropical fruit in Australia (Southern Hemisphere), Department of Primary Industries Queensland (DPI QLD), Wet Tropics Regional Publication, Queensland