One of the not-so-well-known tropical nuts is the Saba Nut, Pachira aquatica of the Bombax family, originally from tropical America.
It will do extremely well in the humid tropical areas of Australia but it will also grow quite well in the subtropical regions of Queensland and New South Wales and there are even some growers in Victoria who are trying this tree in their state, with different success.
This could well be another Macadamia saga, this time with Brazil on the losing end, and maybe Australia becoming the most important grower one day of this useful nut.
Names and distribution
Commonly called 'Mamorana' in Brazil, the Saba tree of medium size with large branches is found along the riverbanks and lagoons throughout the Amazon basin, the Upper Orinoco and in the Guianas. Not only planted as a fruit tree, one sees it everywhere in parks and along avenues of state capitals in Brazil for its ornamental value. It is there known as 'Munguba'. Munguba trees are found as far south as Rio de Janeiro in subtropical Brazil. In higher upland areas, the saba tree grows much larger than its relatives in the wet humid of the downstream Amazon.
The saba nut tree has spread out all over the tropical parts of the world. In the Central American countries like Honduras and Nicaragua, the tree is known under the name 'Provision tree' and is found in Mexico and the West Indian island, Haiti. In many African countries, Angola, Zaire, to name a few, the saba nut is mainly a backyard tree, though a few small commercial plantations exist.
The tree has been cultivated for years in Hawaii, where it is known as 'Malabar chestnut'. Here in Australia there is some confusion with the name, as the saba nut has been called 'Guyana chestnut' as well.
A close relative of the saba nut is Pachira insignis, commonly known as 'Maranhao Nut'. The tree looks quite similar but the seeds are larger than those of the the saba nut. The young leaves and flowers are reputed to be edible.
Another relative is Pachira grandiflora from the West Indies, where the seeds are eaten as chestnuts by the locals.
Flowers and seeds
The tree starts flowering at a very young stage. A RFCA member in Tully reported that his tree was flowering when it was only 2 years old and 2 metres high. The flowers are very large, of a white-yellow colour and lasting for about 24 hours.
The fruit is a large, ovoid, dehiscent capsule 15-20cm in length and 12-14cm in diameter. It has a velvety-rough skin which is a rusty-red colour and marked with deep longitudinal grooves at the junctures of the various segments which make up the fruit. When the fruit is mature, the segments of the capsule open easily, allowing the seeds (20-40) to fall to the ground. While the seeds are closely packed in the capsule, a thin membrane separates them individually. The seed has a flexible, light brown shell which resembles a bean. The kernel consists of a thick leaf, rolled into an irregular shape, which is nearly square. The seeds contain 30% moisture, are oily and when dry weigh an average of 5 grammes. They are composed of 10% shell and 90% kernel. The kernel contains 85% fat. At the ambient temperature of the tropics, the extracted fat has the consistency of petroleum jelly, is white in colour and edible with a pleasant odour, faintly redolent of licorice. The fat, which has industrial potential, can be used in making soap, but would be better utilised if it were refined into an edible product.
Limberlost Nursery has given its customers seeds to taste . The general opinion of tasting the raw seeds was favourable. In tropical countries however, the seeds are seldom eaten raw and are stir fried, cooked or roasted.
Germination and planting
The seeds germinate easily when the fruits mature and fall to the ground. The tree is extremely adaptable and will grow in either dry or wet tropical environments and needs little care. The root system is very vigorous and strong, perhaps exceeding in growth the above-ground portion of the tree. Often the main roots of the tree are bursting out of the ground and, remaining green, will assist in the photosynthesising like the leaves. Some roots can be as large as the bole of the tree.
Personal observations suggest that there will be few problems with phytophthora here in Queensland. Victorian growers mentioned some losses by phytophthora (personal communications). Probably due to the cold winters, the tree weakens and loses its resistance against the ground fungus.
Growers in the Tully area have experienced attacks of leaf-eating insects when the tree is young. They grow out of it with hardly any spraying.
The future for growing Saba Nut trees in Australia can be looked at rather confidently as it has the potential to become a commercial venture.
The Limberlost Nursery is expecting an increasing awareness of this tree and has already started a program for propagating these trees on a large scale. They are readily available now. The backyarder will find it an attractive backyard tree with ornamental value as well.
1. Edible nuts of the World, by Edwin A. Menninger, 1977. Publ. Horticultural Books Inc., USA.
2. Oil Palms and other Oilseeds of the Amazon, by Celestino Pesce, 1941. Transl. Dennis V. Johnson, Publ. 1985 by Reference Publication Inc., Algonac, Michigan, USA.
DATE: January 1996
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