Protabase Record display www.prota.org Triadica sebifera (L.) Small Protologue Florida trees: 59 (1913). Family Euphorbiaceae Chromosome number 2n = 36 Synonyms Stillingia sebifera (L.) Michx. (1803), Sapium sebiferum (L.) Roxb. (1832). Vernacular names Chinese tallow tree, candleberry tree, popcorn tree (En). Boiré, arbre à suif (Fr). Árvore do sebo, pau do sebo (Po). Origin and geographic distribution Triadica sebifera is native to China and Japan, where it is cultivated, but more widely in former times than at present. It was widely introduced as an ornamental tree in the tropics and subtropics, e.g. in northern India, Pakistan, the southern United States and around the Black Sea. In many of these areas it has become naturalized and sometimes weedy. It has occasionally been planted in tropical Africa, where it occurs from Sudan to South Africa. Uses The fruit of Triadica sebifera contains two types of fat: the white, fleshy outer seed coat (sarcotesta) yields a fat known as ‘Chinese vegetable tallow’ or ‘pi-yu’ in trade, while the seed kernel yields a drying oil called ‘stillingia oil’ or ‘ting-yu’ in trade. Chinese vegetable tallow is widely used in China for edible purposes, as a substitute for animal tallow and for lighting. Candles made by mixing 10 parts Chinese vegetable tallow with 3 parts white insect wax are reputed to remain pure white for any length of time and to burn with a clear bright flame without smell or smoke. Elsewhere, Chinese vegetable tallow is used to make soap, as a substitute for cocoa butter and to increase the consistence of soft edible fats. Stillingia oil is used in paints and varnishes, for illumination and to waterproof umbrellas. Both Chinese vegetable tallow and stillingia oil are used as fuel extenders on a small scale. The presscake remaining after tallow and oil extraction is unsuitable as feed for livestock because it contains saponins, but can be used as fuel or as manure. However, the presscake can be detoxified. The leaves contain a dye, used in Indo-China and China to dye silk black. Triadica sebifera is also an agroforestry species and an ornamental. It is a good soil binder and contributes to nutrient recycling. In tea plantations, it is planted as a shade tree. Its wood has been used to make various implements, toys, furniture and Chinese printing blocks. Because Triadica sebifera tolerates many unfavourable soil conditions and some frost, interest in it has grown again since the 1980s as a potential fuel and biomass producer on marginal soils, particularly in the south-eastern United States, but there it is now considered a noxious invasive weed. In traditional medicine in China, the root bark is utilized for its diuretic properties and is said to be effective in the treatment of schistosomiasis. The leaves are applied to cure shingles. Production and international trade After the Second World War, when there was a shortage of drying oil for paint, interest in stillingia oil increased and the oil reached prices of UK£ 200 per t in the world market. Experimental plantations were established in several countries, but outside China the trials did not meet expectations. A serious obstacle in exploiting the tree commercially has been the large amount of labour involved in collecting the ripe fruits by hand. At that time China exported annually 4000–5000 t. At present, almost all stillingia oil and Chinese vegetable tallow are produced and used locally in China. The annual Chinese vegetable tallow production has been estimated to be about 50,000 t; export is almost zero at present. Properties The air-dried seed of Triadica sebifera consists of: water 5%, fleshy seed coat (sarcotesta) 30%, dry seed coat (shell) 40% and kernel 30%. The sarcotesta yields 50–80% Chinese vegetable tallow (whitish, hard, edible but tasteless), while the kernel yields 50–60% stillingia oil (strong smelling, not edible, emetic and purgative). The fatty acid constituents of Chinese vegetable tallow are: lauric acid trace, myristic acid 0–4%, palmitic acid 58–72%, stearic acid 1–8%, oleic acid 20–35%, linoleic acid 0–2%. The fatty acid constituents of stillingia oil are: palmitic acid 6–9%, stearic acid 3–5%, oleic acid 7–10%, linoleic acid 24–30%, linolenic acid 41–54%. Stillingia oil also contains 2,4-decadienoic acid 4–5% and 8-hydroxy-5,6-octadienoic acid. Stillingia oil is not stable and undergoes changes even in the seed. When seed is harvested within 60 days of flowering, the oil is relatively rich in palmitic acid and poor in linolenic acid. Prolonged storage of high-linolenic stillingia oil leads to formation of estolide (ester-like compounds consisting of a fatty acid esterified with a hydroxy-fatty acid). The presence of unstable and easily oxidized estolide may explain the good drying qualities of stillingia oil. Partly due to these changes, large differences in the composition of stillingia oil have been reported. Stillingia oil is poisonous and makes Chinese vegetable tallow inedible if accidentally mixed with it. It has inflammation- and tumour-promoting properties. The leaves of Triadica sebifera are not browsed by cattle; they contain constituents such as gallic acid, astragalin (active against lymphatic leukaemia cells), (–)-loliolide, kaempferol, quercetin, β-sitosterol glycoside, and a phenolic glycoside with antihypertensive activity. Triadica sebifera contains hydrolysable tannins, including geraniin and ellagic acid. The stem bark contains various triterpenoids and 3,4-di-O-methyl ellagic acid. The bark contains a sticky milky-white sap which may act as a skin irritant and purgative. The wood of Triadica sebifera is hard, with fine texture and nearly white; its density at 15% moisture content is about 500 kg/m3. Description Monoecious, deciduous, small tree up to 13 m tall; stem often gnarled; bark whitish grey with vertical cracks, containing white latex. Leaves alternate, simple and entire; stipules ovate to triangular, up to 2 mm long; petiole 2–7 cm long, with a pair of conspicuous glands at apex; blade broadly elliptical to obovate or nearly orbicular, up to 9.5 cm × 10 cm, base obtuse, apex acuminate, pinnately veined with 7–10 pairs of lateral veins. Inflorescence a terminal or axillary thyrse, 4–16 cm long, yellowish green, basal part with female flowers, upper part with clusters of male flowers; bracts and bracteoles 1–2 mm long, often with a pair of glands at base. Flowers unisexual; pedicel 2–3 mm long; calyx 3-lobed; petals absent; male flowers with 2–3 stamens; female flowers with superior, 3-celled ovary, style ending in 3 stigmas 3–5 mm long. Fruit a dry, 3-lobed or grooved, nearly globose capsule, 1–1.5 cm in diameter, opening regularly and nearly simultaneously septicidally and loculicidally, 3-seeded. Seeds attached to the central columella for a considerable time after ripening, globose to flattened ovoid, 6–9 mm × 4–6 mm × 5–8 mm, covered with a whitish, waxy, persistent sarcotesta; seed coat (shell) hard, brittle, brown. Other botanical information Triadica comprises 3 species, all native to eastern Asia. Growth and development Under favourable conditions Triadica sebifera is a fast grower: until it is 8–10 years old, it can grow about 1 m per year; after 20 years, it may be up to 13 m tall with a stem diameter of up to 40 cm. Flowering starts 3–4 years after planting. The flowers are very fragrant and often visited by bees and other insects. The fruits take 3–4 months to ripen. In seasonal climates, the tree is very ornamental with reddish inflorescences with green-yellow flowers in spring, conspicuous white seeds that remain long on the tree a few months later, and with leaves turning a brilliant red in autumn. In China trees are long-lived and said to become hundreds of years old. To run wild in areas where it has been introduced, Triadica sebifera needs a fair amount of annual rainfall or a permanently moist soil. In Florida and Louisiana (United States), where such conditions occur, it has been declared a noxious weed. Ecology Triadica sebifera occurs in subtropical to warm temperate climates. It can withstand a few degrees of frost and tolerates a wide range of soils with pH 5–8. It thrives in waterlogged and moist locations and survives salt-water flooding. Optimum conditions are an annual rainfall of 1500–3000 mm, temperatures of 15–30°C, elevations from sea-level up to 800 m, and well-drained clayey-peat soils. In the United States it survives in unburned grassland, in disturbed and undisturbed upland and wetland sites. It is shade tolerant and grows under closed canopies. In India it can be found on gravelly soils in ravines. Propagation and planting Triadica sebifera is most commonly propagated by seed, but vegetative propagation by cuttings, layering, top-grafting and root suckers (which are formed abundantly) is also possible. The weight of 1000 seeds is about 150 g. Seeds are sown directly in the field, 3–4 per hole and at 5 m distance between holes, giving 400 trees/ha. Seeds are usually planted in early spring or late autumn. Large seeds have the best germination rate (90%). In India soaking seed in concentrated sulphuric acid for 10 minutes has promoted germination effectively, while plants grown from suckers showed better growth than seedlings. An in-vitro multiplication technique based on axillary bud proliferation has been developed. Management In plantations of Triadica sebifera trees should be pruned and trained to a convenient size for hand harvesting. Diseases and pests Triadica sebifera has no serious diseases or pests. However, fungi such as Pseudocercospora stillingiae causing leaf spot and Armillaria tabescens (synonym: Clitocybe tabescens) causing mushroom root rot are known to attack it.