Pendula nut

Related species
Description and phenology
Distribution, abundance and ecology
Uses and economic potential
Collection methods and yields -
Propagation and cultivation methods
Research contacts

Paulo de T. B. Sampaio

Family: Chrysobalanaceae

Species: Couepia Longipendula Pilger

Common names: Castanha de galinha, castanha pêndula (Loureiro et al. 1979), pendula nut (proposed English name).

Related species

Couepia edulis Prance - The cutia nut is a large tree (20-35 m in height by up to 1 m DBH) found in the terra firma (non-flooded upland) forests throughout most of Amazônia it is occasionally cultivated, more commonly protected when a swidden is opened. The fruit resembles that of the pendula nut (see below) but has a hard woody epicarp, extremely difficult to crack open, containing a slightly larger nut. It fruits from November to May in the middle Solimões River basin. The nut is very popular in the interior of Amazônia consumed either raw or toasted. The tree is reputed to bear more heavily than the pendula nut (Cavalcante 1988). The nut contains 73% oil.

Couepia bracteosa Benth - The pajurá is a medium tree (10-25 m in height by up to 0.5 m DBH) of the terra firma forests of central Amazônia to the Guianas; it was frequently cultivated in the Manaus area, commonly protected when a swidden was opened, but has slowly disappeared from the markets during the last decade or so. Unlike the two nut species, the pajurá fruit is a large drupe (to 15 cm long), with a thick fleshy, granular textured mesocarp, that has an attractive aroma and taste when ripe. Fruiting occurs from January to March in the Manaus region. The fruit falls from the tree before it is ripe for consumption, which occurs two to four days later, at which point it is sweet and its flavor and aroma are at a maximum. It maintains this consumption point for only one day or so, however, after which it quickly loses its edible qualities. Although Cavalcante (1988) claims that the mesocarp is the only edible part, and in fact it is the only part consumed near Manaus, it would be surprising if its nut were inedible.

Description and phenology

The pendula nut is a medium to large tree, attaining 30 m in height and 50 cm in diameter at breast height (DBH), with a thin bark (0.5 cm) that ha. a blood-red inner layer, supporting an abundantly branched crown. The leaves are simple, alternate, ovoid-oblong, 8-18 cm in length by 4-7 cm in width, semi-leathery in texture, smooth and lustrous on the upper face, with a pointed tip, all on a short petiole. The inflorescence is characteristic, with a long (up to 100 cm) filiform peduncle, supporting several white-petaled, aromatic flowers. The fruit is an egg-shaped drupe, 4-6 cm in length by 4 cm in width, with a thin epicarp and a fibrous, woody mesocarp. Each fruit contains one large nut, with a light green endosperm and a sweet, mild flavor, measuring 3-5 cm in length by 2-3 cm in width (Cavalcante 1988, Loureiro et al. 1979, Rodrigues 1972).

Around Manaus, the pendula nut fruits during the rainy season, from January to March (Cavalcante 1988). Although several trees are planted at INPA, its flowering season has not been published.

Distribution, abundance and ecology

The pendula nut occurs throughout central and western Amazônia and the western Guiana shield. In Brazil it is found in western Pará, all of Amazonas, and the southern part of Roraima. It is found in the Colombian and Peruvian Amazon as far as the foothills of the Andes, and so probably also occurs in Ecuador. It is not mentioned by RADAMBRASIL (1974) in Acre or Rondônia, Brazil.

To the east of Manaus, RADAMBRASIL (1974) reports an abundance of 0.036 trees/ha in the low plateaus south of Santarém, Pará. Along the Trombetas River, near the frontier between Pará and Amazonas states, INPA's Dept. Silvicultura Tropical (1982) reports 3 trees/ha with diameter at breast height (DBH) ³ 25 cm.

Rodrigues (1972) states that the pendula nut is-common in the forests near Manaus. RADAMBRASIL (1974) reports 0.112 trees/ha in dense forest north of, and 0.013 trees/ha in secondary/primary forest transition areas south of, the Negro River near Manaus. At INPA's A. Ducke Forest Reserve, Marvalhas et al. (1965) reported 7 trees/ha with DBH ³ 15 cm, and 4 trees/ha with DBH 25 cm, while Alencar (1986) reports an average of 6.8 trees/ha. At INPA's Tropical Silviculture Experiment Station (EEST), in SUFRAMA's Agricultural District, INPA (1981) reports only 0.34 trees/ha with DBH, 25 cm along the ZF-2, while Jardim (1985) found 1.2 trees/ha with DBH ³ 20 cm nearby. South of the EEST, INPA-DST (1987) reports an abundance of 0.16 trees/ha at km 52 BR-174, while Proflama (1972) reports 1.4 trees/ha in other parts of the SUFRAMA Agricultural District.

West of Manaus, along the varzeas (the annually flooded white water river terraces) of the Purus River, Atlantic Veneer da Amazônia (1982) reports 0.06 trees/ha with DBH ³ 25 cm. Slightly further west, at the Forest Research Center (CPF) of the Federal University of Parana (UFPr), in the Polo Juruá-Solimões, FUPEF (1981) reports 1.44 trees/ha with DBH ³ 50 cm and 0.94 trees/ha with DBH ³ 50 cm on the terra firma. RADAMBRASIL (1974) reported 0.098 trees/ha in "open" terra firma forests east of the Juruá River and 0.132 trees/ha in the same formation between the Juruá and the Javarí Rivers. Along the Japurá River, RADAMBRASIL (1975) reports 0.4 trees/ha, while along the Iça River they report 0.115 trees/ha, again on the terra firma.

Rodrigues (1972) states that the pendula nut is common in the forests of the upper Negro River, especially above the mouth of the Curicuriari River, just below São Gabriel da Cachoeira, Amazonas.

It is most common in terra firma forests in central western Amazônia preferring clay oxisols, where the greatest tree sizes are attained, but growing moderately well on sandy ultisols also. Near Manaus, Altman & Souto (1965) report that it can attain the upper canopy when on clay oxisols, even being a dominant species there, but on sandy ultisols it is a component of the understory. It can occasionally be found in varzea areas.

Uses and economic potential

Principal use
Secondary uses

Principal use

Throughout its distribution, the pendula nut is a popular product during its fruiting season as a fresh or toasted nut. Although popular, it rarely is found in the market and when found is only found in shell, never prepared. Its mild flavored, slightly sweet nut is very agreeable fresh or toasted, frequently comparing favorably with the Brazil nut (Bertholletia excelsa).

Secondary uses

The wood of this species is heavy (0.9-1.0 g/cm³), with a dark brown, nearly black heartwood and a clear beige outer layer, both having an irregular grain, medium texture, indistinct odor and flavor. The wood is difficult to work; nonetheless, it is used in civil and naval construction (Loureiro et al. 1979).

The seed contains a clear yellow-green oil (70-80% of dry weight), with semi-drying properties, and which is very susceptible to oxidation (rancifying easily) (Loureiro et al. 1979, Rodrigues 1972). It is occasionally extracted and used in human dicta. Rodrigues (1972) presents some of the physical-chemical properties of this oil (Table 1).

The seed cake, after oil extraction, has excellent flavor, slightly sweet. It is high in protein (32.5% of dry weight), fiber (10.6%) and ash (8.3%), and is therefore an excellent potential addition to the human diet. Both whole ground nuts or seed cake are used to make regional pastries, especially paçoca (mixed with sugar and baked) and bejú (mixed with sugar, kneaded and baked as a cake) (Cavalcante 1988, Loureiro et al. 1979, Rodrigues 1972).

Table 1. Physical-chemical characteristics of pendula nut oil (Rodrigues 1972).

Collection methods and yields -

The ripe fruit falls from the tree and in collected from the ground. This should be done frequently during the harvest season, as the nuts are very popular with forest rodents and wild pig B. They also rancify rapidly (Rodrigues 1972). The nuts are easily extracted from the mesocarp with a knife, as the fibrous mesocarp allows relatively easy penetration.

No yield data has been obtained from either forest or plantation trees grown in full sun. The trees start to fruit within 5 years after planting out into full sun and fruit annually with little apparent year-to-year variation at INPA's A. Ducke Forest Reserve.

Propagation and cultivation methods

Fresh seeds from trees at INPA's A. Ducke Forest Reserve have a mean germination of 83.5% [although Rodrigues (1972) reported 90%], initiating germination within 7-15 days after sowing and finishing 15-21 days thereafter (Magalhães et al. 1979). Germination is of the epigeal type (Rodrigues 1972). Seeds lose viability rapidly (Alencar & Magalhães 1979): 1 month after harvest - 78% germination; 2 months - 10%; 3 months - 0%.

Seedlings of the pendula nut can be obtained by direct sowing of seed into plastic bags or sowing into seed beds with later transplant to plastic bags. Direct sowing into the field is not recommended, however, because seed predators avidly hunt for the seeds. Alencar & Magalhaes (1979) report that seedlings grown in 50% shade attain 60 cm in height and 6 mm in diameter at soil level after 5 months. Grafting has not yet been tried.

Planted in full sun, the pendula nut grows rapidly. At open spacing (6 × 6 m) it forms a very nice horticultural tree, with a low spreading crown, easily harvested. At silvicultural densities (eg 3 × 4 m or tighter) it attains 12 m in height and 20 cm DBH by 8 years on a clay oxisol at INPA's EEST. Its precocity and rapid growth recommend it for agroforestry (S.F. Paitán, Univ. Amazônia Peruana, Iquitos, pers. com.) where experimentation is starting.

Research contacts

MSc. Paulo de T.B. Sampaio, Depto. de Silvicultura Tropical, Instituto Nacional de Pesquisas Amazonicas - INPA, Cx. Postal 478, 69011 Manaus, AM, Brazil.

Prof. Salvador Flores Paitán, Univ. de la Amazônia Peruana, Apartado 764, Iquitos, Loreto, Peru.