|Chinese Tallow Tree
reports on a new potential biodiesel feedstock, the Chinese tallow
tree. It is said to be a potential algae-as-feedstock rival if yield
reports of 1,000 gallons of oil per acre are true. Although it is known
as an invasive nuisance tree, it does have potential for oil extraction
from both its seeds and its woody biomass. In its native Asia, the tree
is already used for a wide variety of product including everything from
transfat-free shortening to silk dye. In America, though, it could pose
big problems because of its invasiveness which is regulated by USDA’s
Farm Bill, making it potentially unused unless changes in its presence
and development are strong enough evidence to support its research and
use. However, farmers contend that they know how to keep the crop under
control while allowing it to be more productive on its current lands.
Primarily found in the south and along the Gulf Coast, it is a hardy and
tolerant tree with 45 to 60 percent oil yield from its seeds alone. In
other countries, the tree is well-maintained and consistent; however,
being wild in the U. S., its oil content and usefulness can vary
greatly, making it potentially unreliable if harvested from wild growth.
Overall, the tallow tree holds great promise in its oil-for-biodiesel
content, so research is underway on how to use this plant to its fullest
ability. Time will tell which view wins in this debated tree’s
Chinese tallow tree is cultivated for its seeds as a source of vegetable
tallow, a drying oil and protein food, and as an ornamental. Fruits
yield two types of fats: outer covering of seeds contain a solid fat
with low iodine value, known as Chinese Vegetable Tallow; kernels
produce a drying oil with high iodine value, called Stillingia Oil.
Tallow is used for manufacturing candles, a layer of wax being placed
over the tallow body to prevent too rapid burning; has excellent burning
quality, and gives an inodorous clear bright flame; also used for making
soap, cloth dressing and fuel. Pure tallow fat is known in commerce as
Pi-yu. Oil is used in making varnishes and native paints because of its
quick-drying properties, in machine oils and as a crude lamp oil. Pure
oil expressed from the inner part of the seeds is known in commerce as
Ting-yu. Oil cakes made from crushed seeds with tallow and oil together
is known as Mou-yu. Residual cake, after oil is expressed, is used as
manure, particularly for tobacco fields. Wood is white and
close-grained, suitable for carving and used for making blocks in
Chinese printing; also used for furniture making and incense. Chinese
prepare a black dye by boiling leaves in alum water. Tree grows rapidly,
developes an attractive crown, and, as leaves turn red in fall, is
cultivated as a shade or lawn tree about houses. It is used as a soil
binder along roads and canals. Chinese place an insect on the tree to
feed; it lays eggs in the seed, making some of the "jumping beans,"
because of movements of larvae inside.
In Chinese medicine, oil is used as purgative and emetic, not as a usual
vegetable oil for humans. Overdose of native medicine probably would
cause violent sickness and perhaps death. Additionally, Chinese use the
plant as an alexeteric, suppurative, and vulnerary, especially for edema
and skin ailments. Decoction of the root bark used for dyspepsia,
considered tonic. Resin from root bark considered purgative. The latex
is an acrid and powerful vesicant.
The fatty acid composition of the oil is: caprylic, 1.50; capric, 1.00;
myristic, 0.97; palmitic, 2.80; stearic, 1.00; oleic, 9.40; linoleic,
53.40; and linolenic, 30.00%. A Hong Kong sample contained 26.8% oil,
with: capric, traces; palmitic, 7; stearic, 3; 2,4-decadienoic, 5;
oleic, 7; linoleic, 24; and linolenic, 54%. Stillingia oil is considered
superior to linseed oil in its drying and polymerizing properties,
probably due to the presence of 2,4-decadienoic acid. Seed meal, left
after the extraction of oil, possesses a high content of protein, and is
a valuable feed and fertilizer. It can be processed into a refined
flour, containing 75% protein, fit for human consumption. The amino acid
composition of the protein is as follows: arginine, 16.6; aspartic acid,
11.7; cistine, 1.3; glycine, 4.9; glutamic acid, 17.3; histidine, 2.9;
leucine, 7.4; lycine, 2.6; methionine, 1.6; tyrosine, 3.7; and valine,
7.8%. The vitamin-B content of the flour compares favorably with that of
wheat-flour. The flour, supplemented with lysine and methionine, is
reported to be superior to wheat-flour. Ethanol extraction of powdered
root bark yielded 0.1% phloracetophenone 2,4-dimethylether, and
reethanol extraction gave xanthoxylin (C10H12O4).
The bark also contains moretenone, moretenol and a new triterpene,
3-epimoretenol. Leaves contain gallic and ellagic acids, isoquercitrin,
and tannin (5.5%) (C.S.I.R., 1948–1976).
Small to large deciduous tree, 10–13 m tall (in 30 years), often with a
gnarled trunk, bark gray to whitish-gray with vertical cracks; stem
exudes a milky poisonous juice; leaves alternate, broad rhombic to
ovate, 3.5–8.5 cm long, 4–9 cm wide, cordate-acuminate at apex, usually
round at base, turning orange to scarlet in autumn, falling early in the
cold season; petioles 1.5–7 cm long, with 2 conspicuous glands at apex
and on each side of scale-like bracts; flowers monoecious,
greenish-yellow, in terminal spikes, 5–10 cm long; fruit a capsule,
subglobose, 0.95–1.7 cm in diameter, 3-valved, with three seeds coated
with a white wax; seeds half-ovate, 0.6–1.0 cm long, 0.43–0.6 cm wide,
0.5–0.77 cm thick, with an acrid penetrating taste. Fl. April–June; fr.
Of the many cvs cultivated, more than 100 are found in Taiwan. Two main
types are 'Eagle-Claw' and 'Grape', varying according to form of
fruit-spikes, fruit-sprigs, fruit stalks and maturing period. (2n
Native to many provinces of central China, especially north of the
Yangtze Valley, and Japan, Chinese tallow tree is also cultivated there
and on Hainan Island, Hong Kong, Taiwan and Korea. It has been
introduced and naturalized into Sri Lanka, and introduced to Indochina,
Bengal, India, Sudan, Martinique, southern United States (S. California,
S. Arizona, and Texas to Florida, north to South Carolina), southern
France and Algeria.
Adapted for growing on canal banks, on steep mountain slopes, granite
hills or sandy beaches, it grows in alkaline, saline or acid soils. Said
to thrive in alluvial forests, on low alluvial plains, and on rich
leaf-molds, growing best in well-drained clayey-peat soils. Favorable
climatic conditions are mean air temperatures of 12.5 to 30.1°C, and an
annual precipitation from 13 to 37 dm. It is a subtropical to warm
temperate plant. It is hardy and able to withstand a few degrees of
frost, but unripened twigs are susceptible to frost injury. It will grow
at elevation of 100 to 800 m.
Propagated by seed, cuttings, layering or top-grafting on seedling
stock. Seed usually sown in late autumn or early spring. Seedlings in
the first year may grow 0.3–0.9 m in height and should be transplanted.
When seedlings are about 1 m tall (in the spring of the third year),
they should be planted out in permanent areas. Tree grows rapidly, 5 to
8.5 m tall with DBH of 13–17 cm in 10 years, and 10–13 m tall with DBH
30–40 cm in 20 to 30 years. When cultivated, trees are grown in
plantations or transplanted to borders of fields or canals, so as not to
interfere with the cultivation of the soil. Chinese also make cuttings
by breaking small branches and twigs, care being taken not to tear or
wound the bark. These are layered and rooted.
Fruits and seeds, about the size of a pea, are harvested by hand in
November and December when leaves have fallen. Plants require from 3–8
years to bear, but then contiue to bear for years, averaging 70–100
years. Trees attain full size in 10–12 years. Seed can be threshed from
the tree and collected by hand (once estimated at less than three cents
per kg). Mechanical methods may be readily adapted to the harvest. When
fruit is harvested by hand in midwinter, they are cut off with their
twigs with a sharp, crescent-shaped knife attached to the end of a long
pole, which is held in the hand and pushed upward against the twigs. The
capsules are pounded gently in a mortar to loosen the seeds from the
shells, from which they are separated by sifting.
In plantations trees should be planted one rod apart each way, giving
400 trees per hectare, and if trimmed to a convenient size for
hand-harvesting, would yield 14 MT seed/ha, containing 2.6 MT oil, 2.8
MT tallow, 1.5 MT protein concentrate, 1.1 MT fibrous coat, and 4.5 MT
shell. Oil, tallow and protein meal would bring about $750 per hectare.
This yield could increase with age. Scheld et al (1980) report yields of
4,000 to 10,000 kg/ha, and cite estimates of 25 barrels of oil per year
as a sustained energy yield. Tallow is separated by placing the seed in
hot water, thereby melting the tallow which floats on the surface, or by
melting tallow with steam and collecting it when it drops off. Solvent
extraction of the tallow from the seed is also used, tallow still
adhering to the seed being removed by an alkali treatment. The fairly
thick hard shell prevents extraction of the oil inside, so that the seed
is crushed and Stillingia Oil is obtained by pressing or solvent
extraction. According to one report, seed contains about 20% oil, 24%
tallow, 11% extracted meat, 8% fibrous coat and 37% shell. Oil keeps
well and probably need not be refined. Seed yields vary with the variety
and age-gradations of the trees, a tree averaging at five years of age
0.453 kg, at 10 years, 3.379 kg and at 20 years, 11.989 kg; yields
gradually decreasing after that. Meal, obtained by the extraction of the
kernel, has a pleasant nut-like flavor, is white and contains 76%
protein. Yields of Stillingia Oil as high as 53% of the kernel have been
reported in some varieties. Flour and protein of Chinese tallow nut
contain vitamin B (Thiamin). In China and other Oriental countries, as
in other regions of the world, large quantities of tallow and oil are
extracted annually from this tree. Tallow mills are erected in
vicinities where the tree is extensively grown. In addition to its
economic value (from $750/ha for the oil, tallow and protein), the tree
is extensively propagated for ornamental purposes. From 200,000–300,000
trees are grown for ornamental purposes alone in Houston, Texas.
Coppicing well, the tree grows rapidly, the mean annual girth increment
2.6–5.2 cm. The wood, weighing only 513 kg/cu m is used for fuel. With
some tolerance to salt, the tallow trees should be investigated as
energy crops for saline situations. Princen (1979), assuming an annual
oil yield of 25 barrels per hectare, estimates that only 24 million
hectares of Sapium would be required to produce a replacement for the ca
8% of our petroleum usage which goes into chemical production. That
means 300 million ha could replace all our petroleum useage (ca 35% of
Brazil, 108% of Argentina, 32% of the USA). Specific gravity of the wood
ranges from 0.37–0.48 (mean 0.44) in samples from 18- to 24-yr-old
trees. Energy values range from 7,226–7,835 Btu/lb (mean 7,586) (Scheld
and Cowles, 1981). Rapidity of coppicing, taproot production, drought
and salt tolerance, and rapid growth rate are attributes leading Scheld
and Cowels (1981) to regard the tree as a promising biomass candidate
(in the warm coastal region of the United States) which can be
established over large acreages by conventional agricultural planting
methods and which can provide woody biomass for direct burning or
conversion to charcoal, ethanol, or reethanol.
Flowers are favored by honey-bees and fruits are readily eaten by birds,
including domestic fowl. It has been considered a desirable plant for
bird-food. Tree is remarkably free of insect pests. The root-knot
nematode, Meloidogyne javanica has been reported (Golden, p.c.
1984). Fungi known to attack this tree include: Cercospora
stillingiae, Clitocybe tabescens, Dendrophthoe falcata, Phyllactina
corylea, Phyllosticta stillingiae, and Phymatotrichum omnivorum.
Chinese Tallow Tree
This tree is native to southern China, where a substantial
industry once revolved around the harvesting and processing of its
waxy seeds. They were thrown into boiling water to remove the wax,
which was skimmed off and used to make candles. The seeds were then
pressed to extract an oil for use in lamps, as a purgative, and for
making oil-paper and soap. These days Chinese tallow tree is grown
mostly as an ornamental, and it is one of the few deciduous trees to
produce good autumn colour in areas with mild winters.
Common name: Chinese tallow tree
Botanic name: Sapium sebiferum
This is a deciduous tree to around 8m (25') tall with a medium
domed crown. In autumn the mid-green leaves turn crimson, with some
yellow, orange and ruby-red foliage. In November and December
greenish yellow flower spikes appear on the tips of the branches,
followed by 3-celled capsules. The fruit ripens and turns brown in
autumn, then splits open to reveal three seeds which are covered
with a layer of pure white wax.
Chinese tallow tree grows from cool to subtropical zones. Grow in
a warm sheltered microclimate in frost prone areas and protect trees
Zones 8, 9, 12-16, 18-21, 25-31, H1
Milky sap is poisonous if ingested
Grows 30 to 40 ft. tall, 25 to 30
ft. wide, with a dense, round or conical crown. Tends toward
shrubbiness, multiple trunks, and suckering but is easily trained to
a single trunk. In colder areas, branch tips may freeze back in
winter, but new growth will quickly cover damage. Leafs out late in
spring. Foliage is dense but flutters in the slightest breeze,
giving tree an airy look. Light green leaves are roundish, tapering
to a slender point; with moderate autumn chill, they can turn
flaming red, plum purple, yellow orange, or mixed colors. For good
color, select a tree while it is in fall leaf. Spikes of tiny
yellowish flowers at branch tips are followed in fall by clusters of
small fruits with a waxy grayish white coating.
beautiful orange, red, purple and yellow autumn foliage provides
autumn colour in climates with mild winters good street tree or
small tree for the home garden insect and disease free drought
tolerant once established
like other members of the family Euphorbiaceae, the stems contain
an irritant milky sap birds disperse the seeds, which germinate
easily, sometimes in places where they are not wanted!
Chinese tallow tree will grow in most soils, but prefers a
well-drained sandy loam enriched with organic matter. Water well
until the tree becomes established. Plant in a warm sunny position
for best autumn colour.
Plants for sale are usually grown from seed and the colour of
their autumn display will vary greatly. To make sure you know
exactly how your tree will perform buy one in autumn. Chinese tallow
trees are widely available at nurseries, or ask your nursery to
order one for you. Prices range from $13 for a 200mm (8") pot up to
$700 for an advanced 200 litre tree 2.5m tall.
'The Garden Plants of China' by Peter Valder, (1999). Florilegium,
ISBN 1876314028, rrp $88.
Copyright 2001 CTC Productions
Complete list of references for Duke, Handbook of Energy Crops
- C.S.I.R. (Council of Scientific and Industrial Research).
1948–1976. The wealth of India. 11 vols. New Delhi.
- Princen, L.H. 1977. Potential wealth in new crops: research and
development. p. 1–15. In: Seigler, D.S. (ed.), Crop resources.
Academic Press, Inc., New York.
- Scheld, H.W. and Cowles, J.R. 1981. Woody biomass potential of
the Chinese tallow tree. Econ. Bot. 35(4):391–397.