The Sapindaceous
Fruits and Nuts
I. INTRODUCTION
The
Sapindaceae are basically a tropical to warm-temperate group of plants
and are relatively non-specialised in their habit of growth. Most are
small to moderate size trees, large shrubs, or woody
climbers. The most specialised growth forms are the rather strange
unbranched
palm-like trees like Talisia,
woody climbers like Paullinia,
and subshrubs or perennial herbs with woody bases. The largest trees
include Schleichera
oleasa (60 m) and Pometia
pinnata (40-50 m).
Many species are important timber trees, Pometia pinnata
being one of the most important timber trees in New Guinea. Blighia sapida wood
is used in West Africa for making furniture, being hard, close grained,
durable and resistant to termites.
Saponins,
which are chemical substances that produce soapy lather, are present in
the fruits, seeds and other tissues of many members of the family, and
genera like Sapindus,
Aphania,
Paullinia
and Serjana
are used in the tropics as soap substitutes.
Crushed material from some species of Paullinia and Serjana
are used in the tropics to stupefy fish in pools or small
streams. However, it is the fruits of the many species in the
family that interest us here. The family comprises some of the most
interesting and fascinating fruits to be found anywhere. The name
Sapindacae is derived from that of the soapberry, Sapindus, whose
fruit is used as a soap substitute, as mentioned earlier.
Other
fruits in the family include the lychee, longan, rambutan, and pulasan,
which are famed throughout the Orient. The family includes fruits that
are extremely sweet through to those that are extremely sour; fruits
that are prepared as savoury dishes; fruits that taste like chestnuts;
and even one with seeds that are made into a stimulating beverage with
three times the caffeine content of coffee: all these fruits shall be
considered in greater detail.
II. THE
WELL-KNOWN SAPINDACEOUS FRUITS
“The
rambutan is the long-haired gentleman of the group, the pulasan having
a modern cut, the lychee is closely cropped and the longan as bald as
the venerable Buddhist monk”. This quotation is very apt as it
describes very well the four well known Sapindaceous fruits. It has
long been recognised, even by the locals, that the four fruits are
closely related. Indeed, they all belong to the sub-family Nepheleae,
and have all been included in the genus Nephelium at one
time or other.
1) Litchi
chinensis,
the Lychee
The
lychee is indigenous to China and is no longer found in the wild. It is
an attractive small to
medium size tree, 10-12 m in height, with a
low-branched, straight
trunk, dark brown bark and
a dense crown. The leaves are alternate, petioled, and even-pinnate,
with 2-4 pairs of leaflets. The rachis
is up to 28
cm long. Leaflets are 5-12 cm long and 2.5-6 cm; wide,
coriaceous, oblong-elliptic to lanceolate, sharply acute, glabrous,
shiny dark green above and
glaucescent
beneath. The young foliage is a beautiful reddish bronze. The tree is
showy when in full
bloom with masses of
tiny apetalous, polygamous flowers
borne on ancillary or terminal many-branched panicles
30 cm
or more long. The flowers are greenish white or yellowish, with small
valvate sepals, fleshy disc, 6 to 10 stamens with hairy filaments, and
a 2 to 3-lobed, 2 to 3-celled, pubescent ovary mounted on a short
stalk, with one ovule in each cell, and a 2-lobed stigma.
Five
different types of flowers have been described, the classification
being based on the length and
functionability of the stamens and on the
development
and
functionability of the pistil. Flowers are unisexual
in function and are classified broadly as either male
or female. Both classes are borne on the same panicle, but tend to
alternate in their periods of opening. The
typical male flower has a vestigial
or abortive
pistil at its centre and this is
surrounded by the 6 to 10
stamens with
filaments up
to 10 mm long. A single
flower remains functional for several days, during which the pollen
sacs ripen and shed pollen in succession rather than all at once.
The
typical female flower has a small but fully developed pistil which
rests on a short stalk. The ovary is usually 2-lobed, each lobe
containing an ovule. It is surmounted by a short style which is cleft
at the apex into 2 rays that expose white sticky stigmatic surfaces
when expanded. The pistil is surrounded by the stamens which have very
short filaments. The pollen sacs do not open and shed no
pollen. Generally only one lobe develops into a fruit, the
other
aborting. Occasionally both lobes develop and a twin fruit results
The
fruit is a nutlet (drupe). The drupes are 2.5-4 cm in diameter, ovoid,
hanging in large or small pendulous clusters. The pericarp is thin,
hard, brittle, dark red, bright red, light red or sometimes yellow, and
is covered with faintly protruding, angular tubercles. The flesh or
aril is white, translucent, very sweet with a faint pleasant aroma, and
separating readily from the large, shiny, dark brown, oblong-elliptic
seed. Better varieties have large fruits, and small, frequently
abortive seeds and bear heavily. The taste has been likened by some to
be suggestive of the Bigarreau cherry or the Muscat grape.
The
main lychee belt of China lies between 15 to 30 degrees north of the
equator, and has an annual rainfall averaging 1600 mm. The wettest
month is June with 263 mm, and the driest January with 94 min. Relative
humidity is 70% in January and 83% in June. Mean maximum and minimum
temperatures are 19°C and 9°C in January and 33°C and 25°C
in July. The best trees in China are located on ridges or
spoil
banks along canals, rice paddies, fish ponds, lakes, and streams, where
their roots can obtain a regular supply of moisture and still have
perfect drainage.
However, they will thrive in
a diversity of conditions.
They are fairly hardy, withstanding
light frosts
unharmed, but will not fruit in a hot humid climate. A humid atmosphere
is not necessary for good growth provided there is an ample supply of
water for irrigation. Acid soil and the presence of mycorrhiza on the
roots in such surroundings is highly beneficial.
‘Lychee nuts’
are prepared by drying the fruits
just as they come from the
tree. The pulp
shrinks away from the
shell into a thin layer surrounding the seed and
has a nutty sweet raisin-like taste.
The Chinese classify the lychee into 2 types:
1)
‘Hill Lychee’ from South Guangdong and Hainan which flowers and fruits
early, and requires a dry autumn, and a winter temperature as low as
12°C, e.g. Tai So, Kwai May Pink, and Haak Ip.
2) ‘Water lychee’
from further north (around Guangzhou), which flowers and fruits later
and requires a dry autumn and a winter temperature as low as 6°C, e.g.
Wai Chee, No Mai Chee, and Kwai May Red.
There is also a ‘tropical’
lychee from the Amboina islands near Java which fruits regularly in
warm areas - the ‘Amboina’ Lychee.
Chinese varieties available in Australia are:
Tai So - This is the most common variety in Australia. A consistent
bearer.
Haak Ip - Fruit quality good. Skin smooth with even pattern.
Seong Sue Wai -
Small fruit, skin slightly rough,
quality
medium to good. Seeds mostly small.
Wai Chee -
Regular bearer, slow growing. Quality medium to good. Last to be
harvested. Souey Tung - Fruit similar to Haak Ip, but lopsided
heart-shaped.
Kwai May Red, Kwai May Pink - Quality very good, seeds mostly small.
Irregular bearer
No Mai Chee - Quality excellent, seeds nearly all small. Fruit
heart-shaped, blotchy red yellow skin colour.
Other Chinese varieties include:
Sum Yee Hong - Earliest cultivar, very large fruit, lopsided
heart-shaped. Quality fair.
Bah Lup - Fruit moderately large. Quality medium.
Fay Zee Siu - Historically famous, large fruit. Quality good, seeds
small.
Kwa Lok - Quality good, skin smooth, alternate bearer.
Chong Yun Hong - Round fruit, thick purplish redskin, flavour fragrant
sweet. Quality good, low yields.
Tim Naan - Fruit small, seed very small. Quality fair.
Sai Kok Zee - As late as Wai Chee but larger fruit.
Other varieties available in Australia:
Bengal - Reasonable bearer but fruit ordinary.
Brewster - Vigorous tree.
Groft - Bears well in Hawaii where others fail.
Muzaffarpur - Fruit large, oblong, seed large.
Other Litchi
species:
There is only one other species, Litchi
philippensis, the Kumingi. This is a wild plant grown
largely in the Philippines and is of little importance.
2) Euphoria longana,
the Longan:
The
longan is native to India, Burma and China. It is a small to medium
size evergreen tree, 10-12 m in height, with a low branched trunk and a
densely foliaged crown. The leaves are alternate, even-pinnate, and
20-30 cm long with 2 to 5 pairs of leaflets. The leaflets are alternate
or nearly opposite, elliptic to lanceolate, obtuse, glabrous, shiny
dark green, light green, or greyish green, coriaceous, 7-15 cm long and
3-6 cm wide, with prominent veins. The flowers are small, yellowish
white and borne in large upright much branched axillary or terminal
panicles up to 30 cm long. The sepals are small and imbricate. Petals
are present but small. The filaments are pubescent and the anthers
glabrous. The ovary is divided into 2, sometimes 3, parts. Longan
flowering in each panicle progresses with the opening of the staminate,
then the pistillate, followed by the hermophrodite, and then finally,
again by the pistillate flowers. There is overlap of flowering types.
The fruit is a
nutlet, globose, about 2.5 cm
in diameter,
yellow or reddish brown, with a nearly
smooth, thin
pericarp, covered by flattened tubercules. The large shiny, dark brown
seed is surrounded by a white, juicy, sweety, gelatinous aril. The
panicle may carry up to 80 fruits. The longan is more cold resistant
than the lychee and is less exacting in its soil and cultural
requirements. Trees have the tendency to overbear. The practice in
China is to thin the panicles severely to increase fruit size. The
prime environment for longan production lies between the latitudes 15
to 28° north and south of the equator. It is most successful in areas
with short and cool winters, followed by high temperatures in spring
and summer.
Dried longans are prepared in the same way as dried
lychees and have a similar taste. The dried arils are used in Chinese
medicine.
In Thailand, the hard-fleshed, crispy varieties are favoured, the
following
being the most popular varieties:
Daw - An early variety.
Dang - Heavy bearer, quality fair, not particularly crisp.
Chompoo - Flesh has a pinkish tinge.
Quality good. Haew - Crisp
flesh, popular in the market, alternative
bearing.
Biew Kiew - Crisp, cream coloured
flesh, heavy cropper.
Bai Dum - Very late variety. Bears
regularly, poor shell colour.
Other varieties include:
China: Fu Yan, Wu Yuan, Xi Xia.
Taiwan: Yang Tao Ye, Chau On Diao, Duan Yu.
U.S.A.: Kohala, Homestead, Sweeney.
Other Euphoria species of promise:
Euphoria
didyma, the Alpay:
A
native of the Philippines, the alpay is a small to medium size tree,
reaching a height of 8-12 m. The leaves
are pinnate with pointed, rather narrow,
prominently veined leaflets. The flowers are in compact clusters, borne
like those of a mango.
The fruits are round, green, warty,
attaining a diameter of about 2 cm, with a shell-like rind. The aril,
which envelopes a big seed, is thin and translucent, but juicy, sweet,
with an agreeable flavour. The tree is found wild and is hardly
cultivated, but is widely distributed both in dry and humid areas.
Euphoria
malaiense, the Mata Kuching:
This
is a Malaysian tree growing to 18 m high. The leaves are divided into 3
to 5 pairs of drooping leaflets, the size and shape of which vary
enormously. The flowers are small, white and scented.
The fruits
are round, up to 2 cm in diameter, with a tough skin which is pale,
dull yellow-brown with dark raised flecks. The aril, which envelops a
big seed, is whitish, translucent, and sweet and in good forms nearly
0.5 cm thick, though usually much thinner. The seed is very large in
proportion, and is shiny brown with a pale patch at the base.
The
tree grows wild in Malaya, Borneo, Sumatra, and the Celebes. In
Malaysia, it is commonly cultivated in the States of Penang and Negri
Sembilan.
The better varieties of the alpay and the mata kuching
could be developed to replace the longan in the hot humid tropics where
the longan does not do well.
3) Nephelium
lappaceum,
the Rambutan:
The
rambutan is highly regarded and common
throughout the Malay Archipelago where
it is indigenous. It is a medium size tree
reaching 15-25 m in height, with a straight high
branched trunk, dark
brownish-grey bark and a rather copiously branched, broad, rounded
or lax crown. The leaves are alternate, petioled, even pinnate
or
spuriously odd pinnate by abortion of one of the apical leaflets, and
with 2 to 4 pairs of leaflets. The rachis is 7-30 cm
long. The leaflets are
alternate or sub-opposite, elliptic, oblong
or
elliptic-obovate, thinly coriaceous, yellowish green, dark
green
or glaucous and dull beneath, glabrescent, 5-20 cm long and 2.5-11 cm
wide.
The inflorescences are axillary and terminal, erect,
widely branched, shorter than the leaves, yellow green, farinose, rusty
pubescent, many flowered and 15-20 cm long. The flowers are
unisexual-dioecious, short-pediceled, apetalous, faintly odourous and
0.25-0.4 cm in diameter. The pedicles are thin, terete, greenish
yellow, and densely rusty pubescent. The calyx is cup shaped, 4 to 6
lobed, yellowish green, rusty tomentose on the outside, beset with
short white hairs within. The disc is small shiny light yellow. There
are 5 to 8 stamens in the male flowers. The filaments are white,
clothed with white woolly hairs, the anthers are small ovoid or
ovoid-oblong, 2-celled and a dull light yellow.
The rudimentary
ovary is small and rusty pubescent. There are 5 to 7 staminodes in the
female flowers. The filaments are clothed with white hairs and the
anthers small and sterile. The ovary
is short stalked, 2-lobed,
rarely 3-lobed, yellowish green, densely clothed with
long dark brown hairs. The cells are as many as the lobes, each with an
ovule. The style is deeply bifid, rarely trifid, yellowish green and
densely covered with brown pubescence.
The trees may be classified into 3 groups:
1) Trees with only staminate flowers. These
are male trees, comprising 40-60%
of seedlings.
2) Trees with flowers which are functionally female.
3)
Trees with hermaphrodite flowers, some of which are functionally female
and some functionally male. This is the most common form in
the
selected cultivars with the percentage of male flowers between 0.05 to
0.9%.
The fruit usually consists of a single nutlet with a
second one represented by a small tubercle at its base, and is globose
or ovoid, red or yellow, beset with tubercles which terminate in a soft
spine, 15-8 cm long and 2-5 cm in diameter. The spines are short or
long, red or yellow, always uncinate at the tip, laterally compressed,
0.54.8 cm long, the tips withering and falling off in some varieties.
The pericarp is glabrous, 0.2-0.4 cm thick. The seeds are 2.5-3.5 cm
long, 1-1.5cm in diameter and arillate. The aril is white, translucent,
sweet and juicy, 0.4-0.8 cm thick and adnate to the testa.
The
rambutan is strictly tropical in its climatic requirements, being
restricted to areas below an elevation of 300 m in the Malay
Archipelago. These trees need a minimum of 2500-3000 mm of rainfall
evenly distributed throughout the year. It is usually grown in areas
within 12 to 15° north and south of the equator.
The seeds are
sometimes eaten roasted. They contain an edible fat. The rambutan is a
highly variable species. The colour of the pericarp is usually in
various shades of red, but some varieties (e.g. R156 and R l63) are
yellow in colour. The taste and texture of the aril also vary
tremendously and falls between two extremes:
1)
Fruits with arils that are soft, very juicy, and which cling
tenaciously to the seed. These are usually very sour, though some can
be quite sweet. When they are eaten, the juice is usually
sucked off the aril and the seed with the remaining aril spat
out or sometimes swallowed.
These fruits are from seedling
trees
and are not
popular, being considered of poor
quality. They are
seldom seen in the markets.
2) Fruits with arils that are very
sweet, comparatively dry and crispy, and which come off the seed easily
with the seed testa adhering to it. A good example of this type of
fruit is Cik Em- bong (R 168) which is very popular amongst the Malays,
and commands high prices in the market. However, a lot of people find
the seed testa adhering to the aril quite objectionable.
Between
these two extremes and with various combinations of sweetness,
juiciness, crispiness, and degree of adherence of the aril to the seed
are the numerous horticultural varieties. Varieties with arils that are
relatively testa-free (arils that come off the seed with only a few
fragments of the seed coat adhering to it) include R3, R156, R160,
Rapiah, and Silengkeng.
Other varieties include:
Malaysia: R4, R7, %99, R134, R161, R162, R170.
Singapore: Jit Lee, R37.
Thailand: Chompoo, Rongrien, Bang Yi Khan, See Tong, Nam Tan Kruad.
Indonesian varieties include:
Lebakbooloos
- Dark red fruits. Aril greyish white, tough, sour-sweet, and firmly
fixed to the seed, parts of seed coat coming away with the flesh.
Seematjan - Most common variety. Fruits dark red, 2 strains ‘Besar’ and
‘Ketjil’.
Seenjonja - Fruit dark wine red. Aril adheres firmly to seed.
Seetangkooweh
- Fruit ellipsoid, strongly compressed. Aril yellowish white, sweet,
adhering firmly to the seed coat which comes off easily.
Seelenkeng
- Much in demand and relished. Aril closely resembles that of the
lychee, is tough, sweet, shines faintly and always has few fragments of
seed coat adhering to it.
Seekonto - Fruits ellipsoid, slightly
compressed. Aril dull greyish white, dry and coarse. Seed coat always
adheres to aril and comes off seed easily.
Atjeh kooning is a collective name for yellow varieties.
4) Nephelium mutabile,
the Pulasan:
The
pulasan, closely related and very similar to the rambutan, is also
indigenous to the Malay Archipelago. It is a small to medium size tree
reaching 10-15 m in height, with a round, smooth,
low-branched trunk, brown bark
and an irregular crown. The
leaves are alternate, petioled, even pinnate or
spuriously
odd pinnate by abortion of one of the terminal leaflets.
The rachis is 7.5-23 cm long.
The leaflets are opposite or nearly so, oblong-lanceolate or
elliptic-lanceolate, coriaceous, dark green, dullish glabrous above,
pale glaucous or
bluish grey and covered with short appressed hairs beneath, 5-15 cm
long and 2-6 cm wide. The inflorescences are axillary and terminal,
erect, clothed with short yellowish or brown pubescence, and 10-20 cm
long. The flowers are polygamous or unisexual dioecious, apetalous.
The
pedicels are thin and pubescent. The calyx is cup-shaped, shallowly 4
to 5 lobed, membranous, and clothed with brown hairs. The filaments are
filiform and short pubescent. The anthers are small, sub-globose and
2-celled. The rudimentary ovary is turbinate arid clothed with brown
hairs. The stamens in the bisexual flowers, or the staminodes in the
female ones, are longer than the calyx. The ovary is sub-ordate, 2 to 3
lobed, coarsely hairy. The style is erect,
pubescent, almost single or deeply bifid,
the limbs becoming recurved.
The fruit consists
of one well developed nutlet, with one or two abortive ones at its
base. It is ovoid, dark red or sometimes yellow, beset with many
obtusely conical tubercles which are often connate at the base and form
toothed crests, 5-6 cm long and 3-3.5 cm in diameter. The tubercles are
robust, erect and 0.5-0.8 cm long with straight brown apex. The
pericarp is thick and shiny yellowish-white inside. The aril is clear,
yellowish white, juicy, sweet, adnate to the testa, and 0.6-0.9 cm
thick. The seeds are ovoid-oblong or ellipsoid, compressed laterally,
2- 3.5 cm long and 1.5-2 cm broad. The testa is thin and greyish-brown.
The
pulasan is widely grown in the western part of Java, and small
plantings exist in other parts of Indonesia, Malaysia, and Thailand.
The fruit is of comparable quality to the rambutan and many consider it
superior. There are numerous varieties of pulasan in Java and these are
divided into two main groups.
1) Dark red fruits with crowded tubercles and an aril which separates
from the seed.
2) Lighter-coloured fruits with widely set tubercles and an aril which
adheres firmly to the seed.
Best
forms of the first group have fruits 7-8 cm long and 4-5 cm in diameter
with yellowish or light greyish-white aril about 1 cm thick. Those of
the second group are smaller.
The pulasan
is more exacting in its
climatic and soil requirements than
the rambutan, and thrives only in a
warm, humid atmosphere, on rich,
well-drained,
continuously moist soils.
Available varieties include P1, P4,
P5, P6, P8, P22, P22, P28, P54, P63, Lee, Merah, Poetih, Sibabad,
Koening.
Other Nephelium
species with edible fruits
These include:
Nephelium
eriopetalum, the Lotong.
Nephelium
glabrum the Redan
Nephelium
philippense, the Bulala
Nephelium
excrospermoides, the Aluao
Nephelium
maingayi, the Liat
Nephelium
chryseum
Nephelium
robustum
These are all wild forest trees bearing small rarnbutan-like fruits,
with thin arils, and which are eaten by the jungle people.
III The
Lesser-Known Sapindaceous Fruits
These fruits are relatively little-known
except in areas where they are cultivated for local consumption.
1) Pometia
pinnata, the
Taun or Dawa:
Also
known as the Fijian longan, Pometia has been previously classified into
10 species. It is now generally accepted that there is only a single
species, Pometia pinnata,
with several
forms of which the best known are: var. pinnata;
var. acuminata;
var. alnifolia;
and var. glabra.
It
is commonly found in Papua New Guinea, Solomon Islands, Western Samoa,
and Fiji, but is used most significantly in Papua New Guinea where it
is known as taun, and in Fiji where it is known as dawa. It is a large
tree, 25-40 m (sometimes 50 m), with a trunk diameter of up to 90 cm.
Trees are erect even when planted in the open. Leaves are large, up to
90 cm long and pinnate with leaflets 30 cm long and 7.5 cm wide. The
leaflets are tomentose, light green, and new flushes are deep wine red.
The flower type is variable and flowers are effectively
unisexual. They may be entirely
functional male, or predominantly
female but with some functional male flowers
on the same
panicle.
The panicles are up to 50 cm long with small cream
white flowers. Newly set fruits may be vivid red, changing to green and
then to pale red when ripe. Other forms are light purple or dull yellow
when ripe. Borne in clusters, the individual fruit have a smooth
pericarp and are round to oblong, and up to 7 cm in diameter. The aril
is semi-transparent, white and quite juicy. The seed is round,
up
to 2.5 cm in diameter. The pericarp is hard and approximately 0.4 cm
thick.
The natural habitat lies within 20° north and south of
the equator, and has a minimum rainfall of 2500 mm annually, evenly
distributed throughout the year.
No clonal varieties have yet
been named. Five different types of seedlings are now growing in the
Cairns area in Northern Queensland:
1) Trees with hard-shelled green and red fruits from Wewak, Papua New
Guinea.
2) Trees with round green fruits from Fiji.
3) Trees with large soft-skinned fruits from New Ireland.
4) Trees with purple and green hard-shelled fruits from New Britain.
5) Trees with smaller brown-skinned fruits from Irian Jaya.
The
Papua New Guinean and Fijian trees have fruited. Both types of fruit
are sweet and of good flavour. Some testa (seed coat) adheres to the
flesh as with the rambutan.
2) Blighia sapida, the Akee:
The
akee is a polygamous tree 7-25 m high, occurring wild in the forests of
West Africa. It is also cultivated in Jamaica where it has become
naturalised. It has bold pinnate leaves 15-25 cm long,
each of which most commonly has 3-6 pairs
of
elliptic, ovate or obovate almost
stalkless
leaflets that diminish in size from the apex to the base of the leaf.
The largest leaflets are 10-18 cm long
and 5-9 cm wide.
The flowers, small, greenish-white, and exceedingly
fragrant, are in axillary racemes, and male, female and unisexual
blooms are on the same
tree. The racemes are pubescent and are 4-15 cm long. The
flowers
have 5 petals and 8 to 10 stamens that in male flowers are
long-protruding.
The somewhat bell-shaped,
leathery rinded fruits, or capsules, 7-10
cm long arid 4-5 cm wide, are
slightly 3-lobed and
depressed at their ends. They become yellow and red as they ripen and
at maturity split lengthwise in 3 places to reveal 3 shiny black oblong
seeds, each surrounded by a fleshy, cream-coloured, brain-like,
nutty-flavoured aril. The aril is relished by many people in the
tropics, especially in West Africa and the West Indies. Arils may be
eaten raw, but usually after cooking, when they resembles scrambled
eggs. They may be simmered in water with salted fish or fried in butter.
Great care
is required in its preparation as
the pink
raphe attaching the aril to the seed is highly poisonous. The peptide,
hypoglycin A, also occurs
in unripe arils and
only those from naturally opened
fruit should be eaten.
Having a high oil content, the aril
soon becomes rancid after ripening, and
becomes unfit to eat. Therefore, arils from unripe, damaged, or fallen
fruits should not be eaten, otherwise harm may result. Akee
poisoning which causes vomiting
has resulted in casualties in Jamaica.
The seeds and pods are also reported to be poisonous.
There are no named varieties.
3) Melicoccus
bijugatus,
the Mamoncillo:
The
mamoncillo is cultivated mainly in the Caribbean region where it is
indigenous. It
is a slow-growing, medium size, upright,
grey-trunked tree, 10-18 m in height. It has shiny pinnate leaves with
2 pairs of pointed elliptic to elliptic-lanceolate hairless
leaflets 5-10 cm long, light green to blue
green in colour. Small, fragrant, greenish-
white flowers
are borne on terminal panicles about 10
cm long. Individual flowers have
4-5 sepals, same number of petals, 8
stamens, and a 2 or 3-lobed stigma.
There are two types of trees:
1) Male or staminate trees.
2) Bisexual trees, most of which are functionally female, although
there may be some functional male flowers.
Cross pollination is
generally necessary for fruit set.
The fertilized flowers develop into a dense
cluster of
small green, round or oblong fruits, 2-4 cm in diameter. When mature,
the fruit has a thin tough,
leathery pericarp surrounding a juicy, white, cream
or light orange translucent pulp (or aril). The flavour ranges
from sweet to sour and the juiciness is variable. The thin
layer
of pulp clings tenaciously to a large seed. Fruits of normal size have
a single oval seed, while occasional larger fruits have two. The
starchy white kernels of these seeds are sometimes eaten as nuts,
preferably after roasting.
There are no named varieties.
4) Paullinia
cupana, the
Guarana:
The
guarana is a large woody climber of the Amazon basin up to 10 m high.
It has a smooth erect stem with a very dark bark. The leaves are
pinnate with 5 leaflets on a common petiole, 7-15 cm long, glabrous same
as the rachis, which, however, is channelled above and concave below
and somewhat striated. The flowers are small, aromatic, whitish or
pale, with 5 sepals, the 2 upper larger and connate. There are 4 petals
with the fifth abortive. Two of the petals are smaller and bearing a
scale below the apex. There are 8 stamens. The ovary is 3-celled,
bearing a 3-pointed style.The inflorescences are in pendulous circinate
cyrnes, 10 cm long.
The fruit is a pear shaped capsule divided
into 3 splitting locules, 1 cm in diameter, of red or yellow colour,
containing 1 or 2 globular or ovoid seeds, 1.2 cm in length, black with
an arillus that changes colour from white to yellow and red.
The
guarana has been cultivated for centuries. It is sometimes cultivated
as a small bush. The seeds are harvested and the pulp and arillus
removed by washing in water. The seeds are then dried, roasted and
shelled. After this, the clean kernels are crushed and then further
dried to form a fine dry powder. This is left to absorb moisture, and
then formed into cakes, which are then baked until they are as hard as
bricks, and are reddish-black or purplish black in
colour. This is
the Guarana of commerce which contains about 5% caffeine. This is used
to make a stimulant drink, popular in South America, which has a bitter
astringent taste and a faint coffee-like odour. Its caffeine content is
about three times greater than an equivalent amount of
coffee. The
astringent action is cause by tannin.
The bark of another species, Paullinia
yoco, the Yoco, also contains caffeine and is also used as
a beverage.
IV The
Little-Known Sapindaceous Fruits
These are often wild or semi-wild trees. Some of them have fruits with
the potential for further development.
1) Cubilia bancoi, the
Kubili:
The
kubili is native to the Philippines and is distributed from Luzon to
Mindanao in primary forests at low to medium altitudes. It is not
cultivated, and although found growing wild in many regions, it is not
abundant. It
is small
to medium size tree, 10-15 m
in height, with
compound leaves. The leaflets are large, smooth, and pointed at both
ends. The flowers are small and are borne on rather large terminal
inflorescences.
The fruit is oval, bright green, 5-6 cm long and
covered with numerous soft spines. The aril is white, fleshy, juicy,
and covers one half of the seed or nut. The nut is roundish-oblong, 3-4
cm long and 2.6-3.8 cm in diameter, dark red, depressed at point of
attachment and is covered with a very thin seed coat. It is of
excellent quality and flavour when boiled or roasted like chestnuts,
and has been claimed by some to be one of the best flavoured nuts.
Others, however, consider it quite bland. Unlike the chestnut, it does
not keep for long under ordinary room conditions.
It grows well
at low to medium elevation in areas with evenly distributed rainfall,
and the better varieties should be brought into cultivation.
2) Diploglottis cunninghamii,
the Native Tamarind:
A
native of Australia, it is widespread over southeastern Queensland to
southern New South Wales.
It is a small to medium
size tree, 10-20 m in height, with a spreading crown. The
leaves are 30-80 cm
long, pinnate, with 8
to 12 leaflets, 10-30 cm
long and 2-6 cm wide,
elliptic to lanceolate, dark green and somewhat hairy above,
densely clothed with velvety brown
hairs beneath.The flowers are small, yellow to brown, hairy and 2 to
3-lobed. The fruit is a
capsule 2-3 cm
across, yellow in colour, 3-lobed, with 3 large seeds enclosed by an
orange-yellow fleshy aril. The jelly-like aril is very sour but
refreshing when chewed, and can be used in drinks or to make jams.
Other Diploglottis
species with edible fruits include:
Diploglottis
campbellii, the Small-leaved Tamarind:
This
is a small to medium size tree, 10-18 m in height, with a spreading
crown. The leaves are 10-30 cm long, pinnate, with 4 to 8 spreading
leaflets, 7-15 cm long and 2-6 cm wide, broadly lanceolate, glabrous
and dull green in colour. Panicles are 5-16 cm long and much
branched. The flowers are small, creamy brown, hairy and
fragrant. The capsule is 4-6 cm across, 3-lobed, small, hard and
yellowish brown in colour. There are 3 seeds, 2 cm across, enclosed by
a red juicy aril. The juicy aril is refreshingly sour but considered by
many to be superior to that of Diploglottis
cunninghamii.
It canbe eaten raw or made into
drinks and jellies.
Diploglottis
diphyllostegia:
A relatively rare, small to medium size tree resembling Diploglottis cunninghamii
and distinguished by its smaller, less hairy, thinner textured leaves.
Capsules are 1-1.7 cm across, yellowish or orange, hairy, 2-3-lobed.
There are 2 to 3 large seeds enclosed by a yellow aril which is edible
and makes an attractive jelly or drink.
3) Talisia olivaeformis,
the Talisia:
The
Talisia is restricted in the wild
to
tropical Central and South America. It
is a tall tree growing to 20 m in height. The leaves
are
pinnate with 1 -2 pairs of broad elliptic leaflets, 5-10 cm long. The
flowers are small, in branched panicles, with 4 to 5 sepals, 4 to 5
greenish or yellowish petals, and 5 to 8 stamens. The fruits
are
similar to those of the mamoncillo, to which it is related. It is
olive-like and is edible, each containing a large stone and lacking
much flesh.
Two trees raised from seed at
the Fairchild Tropical Garden have
fruited at 10 years old.
Since both trees bore
fruit, it is not necessary to have trees of different sexes in
proximity as is necessary with the mamoncillo.
4) Alectryon macrococcus,
the Mahoe:
This
is a rare, small, and ungainly tree to 8 m in height. The fruits are
large, with the colour of a potato, and are perfectly smooth. They hang
in clusters from the branches and become ruptured when mature, exposing
a bright scarlet aril and a glossy chestnut-brown orbicular seed.
The
name mahoe refers to the double fruits. Mature fruits are 3-7 cm in
diameter, subglobose, pendent, glabrous, with one or two lobes, the
second lobe being normal or commonly abortive. The aril is firm,
fleshy, but hardly juicy, scarlet throughout and said to resemble the
peach in flavour and odour. The Hawaiians eat both the arils and the
kernels of the fruits.
Other species of Alectryon
with edible fruits include:
Alectryon
tomentosus:
Native
to Australia, this is a small to medium size tree 10-18 m in height.
Fruits are capsules about 1 cm long, 1 to 3-lobed, covered with rusty
hairs, with black seeds and a scarlet fleshy aril which is edible.
5) Chytranthus
macrobotrys, the Ndugulu:
This
tree is native to Zaire,
Nigeria, Cameroon and the
Republic of Central Africa. It is a
small slow-growing tree, in the understorey of
the
forest, reaching no more than 10 m
in
height and resembling the rambutan in shape, but usually much more
open. Leaves are pinnately compound, the stem of each leaf being of a
dark purplish colour.
Fruits are produced directly on the trunk
much in the manner of the cacao tree, and the fruits even look somewhat
like cacao pods. Inside the fruit are 5 to 20 round and flattened seeds
about an inch
across. These seeds are
boiled and eaten
as nuts and are quite good
eating. The flesh
around the seeds is edible but sour and is used to make a drink to
protect against colds.
Another species of Chytranthus
with edible fruit is Chytranthus mannii,
also a native of tropical Africa.
Also known as Ndugulu, and
from the same area in Africa, is the related
Radlkofera
calodendron. This is not as common as Chytranthus macrobotrys,
and is a much taller and straighter tree. Fruits are produced in the
same manner and are similar to those of Chytranthus macrobotrys.
They are used in much the same way.
Other little-known wild or semi-wild Sapindaceous fruits:
The following is a list of other Sapindaceous trees with edible fruits:
Aphania
senegalensis, the Senegal Cherry:
The
Senegal cherry is a red, astringent, somewhat
sour fruit consumed by natives
of West
Africa. The fruits are sold
in native
markets. The seeds are considered poisonous.
Crossonephelis
pengangensis:
A Malayan tree. The seeds are edible, usually boiled.
Cupania
americana:
The seeds of this tree are used in the West Indies as food and have the
flavour of chestnuts or sweet acorns.
Dienbollia
grandifolia:
An African tree. The fruits contain a single seed in a pulp said to be
edible. The seeds are slightly oily and also edible.
Erioglossum
rubiginosum, the Mertajam or Kalayo:
The edible fruit is 2 cm across and roundish-oblong. Native to the
Malay Archipelago.
Hedyachras
philippensis, the Aglano:
A native of the Philippines, this tree has small edible fruits.
Heterodendron
oleifolium:
An Australian native. Red fruits are eaten by Aborigines of South
Australia.
Otophora
fructicosa, the Lunau:
The dark red fruits are used in the Philippines, where the roasted
seeds taste like chestnuts.
Oxythece
fabrilis:
A large tree found in Guadeloupe and Dominica. The fruits are sometimes
used to make a drink.
Pancovia
harmsiana:
A
tree from Congo and Gabon. The
fruits are
edible and are consumed during times of
want.
Pappea
capensis:
This fruit is the ‘wild preum’ (wild plum) of South Africa, and is
edible. Oil is obtained from the seeds.
Pappea
ugandensis:
A small tree of Uganda, Congo, and Rhodesia. The seeds containing oil
are consumed by the natives.
Sapindus
indicum, the Soapberry:
The
seeds contain 50% of a thick, greenish drying oil. They can be eaten
when quite ripe, but great care should be taken as the latex contained
in the fruit wall is caustic.
Soapberries are also used as soap substitutes. Other species include: Sapindus saponaria;
Sapindus
mukorosii, and Sapindus
oahuensis.
Schleichera
oleasa, the Lac Tree:
This tree is used in India as a host for the Lac insect. The seeds
yield an edible fat, and it is the source of Macassar oil.
Schleichera
trijuga:
The seeds of this tree are also a source of Macassar oil or Kussum oil.
Staphylea
pinnata, the Bladder nut:
The kernels from the seeds taste like pistachios.
Staphylea
trifolia, American Bladdernut:
The seeds contain a sweet oil and are sometimes eaten like pistachios.
V. Conclusion
I
am certain that the list of edible Sapindaceous fruits given here is
far from complete. Many of these little-known fruits like the kubili,
the alpay or the mata kuching deserve more attention and there are
probably many more that have not come to our notice.
During 1985,
two Queenslanders travelled round Indonesia
collecting seeds of rare jungle fruits, and
reported
their experience in the January 1986 issue of the Newsletter of the
Rare Fruit Council of Australia. This is a highly commendable effort as
many of these jungle species should be brought into cultivation before
they disappear under the onslaught of logging and
land clearing.
A list of their “Borneo Collection” is reproduced in the February 1986
issue of Quandong
and includes the following very interesting descriptions of a few
Sapindaceous fruits:
Dimocarpus
longana var. malesiana,
the Isau:
A
small round mid-green fruit about 25 mm in diameter. The thin brittle
shell is covered with small bumps, and
is easily
opened. The translucent flesh is 4-6 mm thick around a single
black seed. The
isau is similar to the longan, very sweet and juicy with a musky or
melon-like flavour reminiscent of a very sweet water melon.
Dimocarpus
longana var. unknown, the Kakus:
Kakus
is another delicious longan-like fruit similar to the isau, but with a
yellow or yellow- brown pebbly shell. Sometimes larger than the isau.
The sweet musky flesh is a degree less juicy than isau but has a more
distinctive smoky flavour, somewhat rockmelon-like.
Nephelium
maingavi, the Liat:
A small (35x25 mm) sweet and juicy rambutan-like fruit, slightly acid
with a hint of mint.
Nephelium
sp., the Pangkal:
Often
sour, but this variety was sweet when fully ripe. Round, bright red
fruit, 5 cm in diameter, covered with short dense hairs.
Nephelium
sp., the Sibau:
Like a small rambutan, good flavour, sweet.
As far as I know, Dimocarpus
longana is a synonym of Euphoria longana.
The
isau and the kakus could, therefore, simply be local tropical
varieties of the longan. Or, more likely
perhaps, they are
local varieties of Euphoria
malaiense, the mata kuching, which is also
indigenous to Borneo, and which looks and tastes very much like the
longan (which is not indigenous to Borneo). In peninsular Malaysia,
imported longans are often referred to as mata kuching. The species is
quite variable, those from Penang having small blunt leaflets, whilst
further south are
forms with larger pointed leaflets. Most Nephelium fruits
look and taste rather like the rambutan,
and it is interesting to find out what species
the pangkal and the sibau belong to.
It is hoped that many more such trips will be undertaken in future,
perhaps to other tropical regions of the world.
VI. References
Most of the information given in this article is gleaned from the
following sources:
A: Periodicals
The
following Societies and Associations publish regular Newsletters and
Yearbooks which contain articles on rare, exotic and tropical fruits
and nuts:
1) West Australian Nut
and Tree Crop Association,
P.O. Box 565, Subiaco, Western Australia 6008. If you are reading this
article, and are not yet a member, you should join without
further delay and support Western
Australia’s own
Association. Regular meetings are held and
the
Association publishes a quarterly newsletter, ‘Quandong’, and an annual
Yearbook loaded with articles on tropical fruits and nuts.
2) Rare Fruit Council of
Australia,
P.O. Box 707, Cairns, Queensland 4870. The R.F.C. of A. has been in the
forefront on the introduction of tropical fruits into Australia. It
publishes a bi-monthly Newsletter. I have been a member for two years
now, and have found the Newsletter a storehouse of information on
tropical fruits. It is also an organisation that deserves our
support.
3) California Rare Fruit
Growers, Inc.,
The Fullerton Arboretum, California State University, Fullerton,
California 92634, U.S.A. The CRFG is now in its 18th year and has
become a world leader in the
area of rare fruits. Southern California
has a climate very similar to that
of southwestern
Australia, and growing conditions ‘The Fruit Gardener’ and an annual
Yearbook to be renamed ‘Journal’. Both are crammed with information on
tropical and sub-tropical fruits.
4) Rare Fruit Council
International,
13609 Old Cutler Road, Miami, Florida 33158, U.S.A. Founded in 1955,
this is the parent organisation of the R.F.C. of A. It publishes a
monthly Newsletter, and an annual Yearbook.
B: Books
1) Allen, B. M.,
Common Malaysian Fruits, Longman, 1975. This is a very good
introduction to Malaysian fruits.
2) Bailey, L. H.,
The Standard Cyclopedia of Horticulture, The Macmillan Company, 1928.
This is a very good source of information for many tropical fruits.
There are very good drawings of tropical fruits. Some
of the nomenclature
is out of date, e.g.
the Mamey Sapote is listed under Lucuma
and not Pouteria.
However,
most information on tropical fruits is never out of date! There is
usually a set in the local library.
3) Bose, T. C.,
Fruits of India, Tropical and Sub-tropical, Naya Prokash, 1985. This is
an excellent new book on tropical fruits.
4) Coronel, R.E.,
Promising Fruits of the Philippines, College of Agriculture, University
of the Philippines, 1983. This is another excellent new book on
tropical fruits.
5)
Elliot, W.R. and Jones, D.J., Encyclopaedia of Australian
Plants, Lothian Publishing
Company, Vol. 2, 1982; Vol. 3, 1984. A very good source of information
on Australian species.
6) Everett, T.H.,
The New York Botanical Garden’s Illustrated Encylopedia of
Horticulture, Garland Publishing, Inc., 1981. Information on some of
the better
known tropical fruits is
given.
7) Hedrick, U.P.,
Sturtevant’ s Edible Plants of the World, Dover Publications,
Inc. 1972 (originally published in 1919). This book lists
plants
of all types with edible parts. Some of the nomenclature is also out of
date.
8) Menninger, E. A.,
Edible
Nuts of the World, Horticultural Books, Inc., 1977.
This is a very interesting book that covers all types
of
nuts, both the common as well as the rare and unusual types.
9) Ochse, J. J. et al,
Tropical and Subtropical Agriculture, Macmillan Company, 1961. This
book is seldom included in the recommended lists of books on tropical
and subtropical fruits that I have come across. However, I
find it
one of the most informative books of all. Volume 1 covers most of the
important tropical and subtropical fruits, and Volume 2 covers the
other crops. The illustrations are excellent. It is out of print but
can be borrowed through the Library Services.
10) Page, P.E.,
Tropical Tree Fruits for Australia, Queensland Department of Primary
Industries, 1984. This is another one of the excellent new books on
tropical fruits brought out in the last three years.
11) Popenoe, W.,
Manual of Tropical and Subtropical Fruits, Hafner Press, 1920. 66 years
old and still most useful! For many years it was the only comprehensive
book on the subject.
12) Purseglove, J. W.,
Tropical Crops, Longman, ‘Dicotyledons’, 1968; ‘Monocotyledons’, 1972.
This is a highly informative book.
13) Sturrock, D., Fruits of
Southern Florida, Southeastern Printing Company, 1959. A good
introductory book.
14) Uphof, J.C.Th.,
Dictionary of Economic
Plants, 2nd Edition, Verlag von J. Cramer,
1968. This book lists all plants with economic use.
Note: Information on the Ndugulu is supplied by Paul Noren of Bangui,
Republic of Central Africa.
Back to
Ackee Page
Longan Page
Lychee Page
Mamoncillo Page
|