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Eucalyptus sp.


Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.

  1. Uses
  2. Folk Medicine
  3. Chemistry
  4. Toxicity
  5. Description
  6. Germplasm
  7. Distribution
  8. Ecology
  9. Cultivation
  10. Harvesting
  11. Yields and Economics
  12. Energy
  13. Biotic Factors
  14. References


Turnbull (1950) reflects that when Dampier landed on the Australian coast, no one but the aborigines knew eucalypts. The aborigines used them for boats, boomerangs, and spears. Presently Eucalyptus provides ca 25% of Australia's peeler logs. Back in 1950, chemical industries used eucalypts mostly for pulping and tanning. Many eucalypts are valued as firewood for fueling waterpumps, rural power plants, bakeries, laundries, even mines in Australia, the better species burning steadily, giving off much heat and little ash. Initially grown as a timber tree in the US, it is now most widely used for fuel, shelterbelts, windbreaks, and for hardwood fiber (Ag. Handbook 450). Around 1950, Eucalyptus oils were produced at rates of 870,000 liters a year. About 1/6 was used in Australia for industrial purposes 1/24 for medicinal purposes, the remainder exported, the bigger half for medicinal purposes. Eucalyptus are important honey trees. Quoting earlier works, Castillo-Borboran (1981) states, "a eucalypt tree drives away mosquitoes from the vicinity it is planted."

Folk Medicine

Reported to be anesthetic, anodyne, antiperiodic, antiphlogistic, antiseptic, astringent, deodorant, diaphoretic, disinfectant, expectorant, febrifuge, fumigant, hemostat, inhalant, insect repellant, preventitive, rubefacient, sedative yet stimulant, suppurative, tonic, and vermifuge, eucalypts are a folk remedy for abscess, arthritis, asthma, boils, bronchitis, burns, cancer, catarrh, cellulitis, colds, colic, coughs, croup, diabetes, diarrhea, diptheria, dysentery, encephalitis, enteritis, erysipelas, fever, flu, gangrene, hemorrhage, inflammation, laryngalgia, laryngitis, leprosy, malaria, mastitis, miasma, pharygnitis, phthisis, rhinitis, sores, sore throat, spasms, trachalgia, tuberculosis, tumors, worms, and wounds (Duke and Wain, 1981).


Strangely, I find no proximate analysis data for the eucalypts, but a plethora of essential oil analyses.


In large doses, eucalyptus oil can be fatal. The pollen is said to be allergenic. The bark or wood of many species is said to induce dermatitis.


Some shrubs, but mostly tall trees, including some of the tallest in the world. The bracteate infloresence consists of usually several perfect white, yellow, or red flowers, often in axillary umbels, corymbose or paniculate clusters. The ovary has 3–6 locules with many ovules. The fruit is a hemispherical, conical, oblong or ovoid hard woody capsule, valvately dehiscent. Usually only a few seeds are fertile in a given capsule. Seeds are usually wind-dispersed, a month or two after the fruits ripen.


Reported from the Australian Center of Diversity, some eucalyptus species are reported to tolerate alkali, clay, drought, fire, frost, fungi, heat, heavy soil, high pH, insects, laterite, limestone, podzols, poor soil, salt, savanna, slope, waterlogging, weeds, and wind. Under natural conditions, hybrids may form between species of the same subgeneric grouping. In this book, I treat only a few important energy eucalypts of the hundreds of species known. (2n = 22, 20, 24, 28, etc.)


Mainly native to Australia, with a few species occurring naturally in New Guinea, the Philippines, and Timor. Eucalypts have been planted to a limited extent in Arizona, Florida, Mississippi, and Texas, to a greater extent in California and Hawaii.


Ranging from Tropical Thorn to Moist through Warm Temperate Desert Bush Savanna to Moist Forest Life Zones, eucalyptus is reported to tolerate annual precipitation of 1.4 to 26.2 dm (mean of 28 cases = 9.8), annual temperature of 12.3 to 27.9°C (mean of 27 cases = 19.5), and pH of 5.0 to 8.3 (mean of 25 cases = 6.1) (Duke 1978, 1979).


Most eucalypt seed need no pretreatment, although a few (not treated here) require stratification for 3–4 weeks at 3–5°C. In the continental US, seed are rarely sown directly in the nursery, a practice common in Hawaii. Rather, seeds are germinated in pots, boxes, or flats in porous light sandy loam, covered with 2–3 mm of fine sand, peat, or sphagnum, best in a mist chamber, as the seedlings are delicate. According to Castillo-Borboran (1981), the optimum temperature for germination of most species is about a constant 25°C. Hardened seedlings are lifted by the leaf tips into individual containers which will be ready for outplanting in 4 to 5 months. Some species root better than others; sapling twigs with juvenile leaves tending to root better.


Good seeds are produced by most species at 10 years or younger. Opened capsules are vigourously shaken to remove seeds.

Yields and Economics

Yields of firewood may run from 1–70(-118)m3 /ha/yr m3/ha/yr (Fenton et al., 1977; NAS, 1980a). With one third of the world's population depending on wood for cooking and heating, the economic importance of eucalyptus is vast. They are, of course, the most important element in the Australian forests, making up 95% of the total flora (Mariani et al., 1981).


During World War II, producer gas attachments were fitted to trucks and cars in Australia (over 5,000 trucks or cars engaged in essential transport). Charcoal supplier had to be organized accordingly, wood being converted to charcoal at the rate of 85%, consuming millions of "super feet" per annum, mostly in portable charcoal kilns. In Australia, Stewart et al. (1979) note that Eucalyptus sp. have a popular reputation for high growth rates, and high intensity hardwood plantations have been successfully established in Brazil, California, and elsewhere. Where not native, Eucalyptus feeders may be absent, and annual yields up to 40 MT DM/ha (South Africa) and 33 (India) are reported. In Australia, pulpwood production of 21 m3/ha (=12–13 MT DM/ha) annually are possible on short rotations in appropriate localities. Conservationists becry the clear-felling of native Eucalyptus forests to export woodchips to Japanese papermills, but opposing foresters see a higher level of utilization by combining sawlog removals With chipping of poor quality material which, if left standing, would inhibit regeneration. Clear-felling has been allocated 2,440,000 ha (42,000 annually cleared). In 1975–1976, 2,330,000 MT green chips were produced, which may be scaled up to 4,300,000. At an assumed 55% dry matter, this is 2,400,000 MT dry chips. Energy analyses suggest that methanol could be produced from wood with an overall efficiency (i.e. gross liquid fuel output/total energy and feedstock input) of 33% for methanol and 16% for ethanol. Assuming a wood cost of $40/MT, production costs would be about $0.23 liter for methanol, $0.52 for ethanol. "The estimated cost of production of methanol from coal is much lower than the cost from biomass." Where coal reserves are large, it is not economically wise to consider biomass as an alcohol base at present. The cost of ethanol from wood using the Rheinau process is estimated at $650 MT, about twice the cost of producing methanol from wood. Woodchips from Eucalyptus are estimated to yield 600 kg sugar or 275 kg ethanol per MT dry wood. As the process energy requirements are greater than that which can be generated from the lignin residues, additional wood is required as fuel (Stewart et al, 1979). The essential oil of Eucalyptus sp. was tested in a small spark ignition engine. Performance was very good except that there were problems starting a cold engine on straight Eucalyptus oil. These could be readily overcome by adding 20 to 30% alcohol or gasoline. Research octane rating of Eucalyptus oil was 100. Viscosity was higher than for gasoline, but an oversize main jet nozzle in the carburetor overcame that problem. Eucalyptus oil has,a lower calorific value per unit weight than gasoline (41.2 vs 46.5 MJ/kg), but its higher specific gravity (0.9166 vs 0.735) results in higher calorific values per unit volume (37.8 vs 34.2 MJ/litre). Engine thermal efficency was slightly high for Eucalyptus oil (mean 14.9 MJ/HP compared with 16.1 MJ/HP for gasoline), but this may have been due to better engine tuning as the gasoline engine gave 4 to 6% carbon monoxide compared with around 1% for Eucalyptus oil. This type of Eucalyptus oil appears to be a premium quality finished fuel for a spark ignition engine (Stewart et al, 1982). Harwood's table (1981), reproduced below, certainly suggests that eucalyptus is the way to go for energy plantation.

Plant Fuel MT/ha/yr kcal/kg Mcal/ha/yr
Eucalyptus Firewood 10–32.5 3000 30–97.5
Saccharum Alcohol 2.52 6400 18.2
Manihot Alcohol 2.02 6400 12.9
Dende Oilseed 2–5 9516 19.0–47.6

Biotic Factors

Nematodes affecting Eucalyptus include: Criconema, Criconemella, Cryphodera, Helicotylenchus, Hemicyoliophora, Meloidogyne, Morulaimus, Paralongidorus, Paratylenchus, Pratylenchus, Radopholus, Scutellonema, Tylenchorhynchus, Tylodorus, and Xiphinema (Golden, p.c., 1984). Agriculture Handbook No. 165 (1960) lists the following as affecting Eucalyptus sp.: ?Actinopelte dryina (leaf spot), Agrobacterium tumefaciens (crown gall), Armillaria mellea, Bagnisiopsis eucalypti, Botryosphaeria ribis, Botrytis cinerea, Ceratostomella echinella, Clitocybe tabescens (mushroom root rot), Coremium glaucum, Corticium ephiphyllum, Cryptosporium eucalypti, C. eucalypti, Diaporthe medusaea, Didymosphaeria eircinnans, D. epidermidis, Diplodia australiae, D, eucalypti, D. microspora, D. tenuis, Fomes applanatus (heart rot), F. robustus, Fusarium oxysporum var. aurantiacum (seedling blight), Gloeosporium capsularum, Harknessia uromycoides, Hendersonia coryneoidea, H. eucalypti, H. eucalypticola, Heterosporium eucalypti, Hypocrea consimilis, eucalypticola, Heterosporium eucalypti, Hypocrea consimilis, Hypocrea consimilis, Hypoderma eucalypti, Macrophoma mollerian, Melanconium globosum, Monochaetia desmazierii, Mycosphaerella molleriana, Nectria eucalypti, Pestalotia truncate, Pezizell carneo-rosea, P. oenotherae, Phragmodothidea eucalypti, Phyllosticta extensa (leaf spot), Phymatotrichum omnivorum (root rot), Physalospora latitans, P. rhodina, P. suberumpens, Polyporus gilvus (wood rot), P. hirsutus (wood rot), P. vellereus, P. versicolor (wood rot), P. schweinitzii (heart rot, butt rot, root rot), P. sulphureus (heart rot, butt rot, root rot), Poria cocos, P. versipora, Scleroderris eucalypti, Septobasidium curtisii (felt fungus), Septonema multiplex, Septoria ceuthosporioides, S. mortolensis, Septosporium scyphophorum, Sphaeronema eucalypti, Sphaeropsis macrospermum, Stereum hirsutum (wood rot), Stomiopeltis sp., Valsa eucalypti, and Volutella coronata. In addition, Browne (1968) lists the following as affecting Eucalyptus sp.: (Fungi) Coltricia aureofulva, Cytospora australiae, C. eucalyptina, Fusarium spp., Harknessia eucalypti, Helicobasidium compactum, Inonotus tabacinus, Phytophthora cactorum, P. cinnamomi, Pleurotus lampas, Polyporus baudoni, Pycnoporus coccineus, Pythium intermedium, P. irregulare, P. ultimum, Readeriella mirabilis, Rhytisma eucalypti, Sclerotinia fuckeliana, Septoria mortolensis, Thanatephorus cucumeris. (Angiospermae) Amyema miquelii, Cassytha glabella, Cuscuta campestris, Phrygilanthus sp. (Coleoptera) Alcidodes haemopterus, A. subvillosus, Analeptes trifasciata, Apate monachus, Bostrychopsis jesuita, Callidiopste scutellaris, Chrysolagria naivashana, Colasposoma amplicolle, Derolagria coriacea, Dicasticus mlanjensis, Doliopygus chapuisi, D. serratus, Eucolaspis brunnea, Lema armata, Lobotrachelus incallidus, Oemona hirta, Oncideres amputator, 0. canidida, Orthorhinus cylindrirostris, Parapoderus fuscicornis, Paropsis obsoleta, Peribrotus pustulosus, Phoracantha recurve, Platypus hintzi, P. omnivorus, Rhadinosomus lacordairei, Scarites procerus, Steirastoma breve, Tetracyphus odotomus, Triphocaris acanthocera, T. mastersi, T. solida, Uracanthus triangularis, Xyleborus truncatus. (Hemiptera) Agonoscelis pubescens, Aleuroclava eucalypti, Anoplocnemis curvipes, A. tristator, Aphis gossypii, Apiomorpha duplex, A. munita, A. ovicola, A. sloanei, Cardiaspina albitextura, C. vittaformis, Ctenarytaina eucalypti, Drosicha stebbingi, Dysdercus superstitiosus, Eucalyptolyma maideni, Helopeltis anacardii, H. schoutedeni, Icerya purchasi, Mietis profana, Ptyelus grossus, Scolypopa australis, Sephena cinerea, Siphanta acuta. Hymenoptera. Perga affinis, P. dorsalis, Phylaeteophaga eucalypti, Podomyrma adelaidae, P. gratiosa. Isoptera. Allodontermes morogorensis, Ancistrotermes latinotus, Coptotermes curvignathus, C. frenchi, Heterotermes platycephalus, Hodotermes mossambicus, Kalotermes brouni, Macrotermes bellicosus, M. goliath, M. natalensis, Microtermes spp., Neotermes insularis, Odototermes redemanni, Porotermes adamsoni, Pseudacanthotermes militaris. Lepidoptera. Abantiades labyrinthicus, Acathopsyche sierricola, Achaea catella, A. faber, Acrocercops hoplocala, A. laciniella, Animula herrichii, Austrocaligula eucalypti, Busseola fusca, Charagia lignivora, Chelepteryx collest, Chenuala heliaspis, Clainia ignobilis, Crypsiphona occultaria, Ctenopseustis obliquana, Dasychira georgiana, Declana floccosa, D. leptomera, Destolmia lineata, Doratifera oxleyi, D. vulnerans, Endoclita undulifer, Epicoma melanospila, Eumeta rougeoti, Eupselia carpocapsella, Gastrophora henricaria, Heliocausta hemitelis, Heliozela prodela, Hippomacha callista, Hyalarcta huebneri, Illidgea epigramma, Machimia tentoriferella, Metanastria latipennis, Metara elongata, Nola lugens, N. metallopa, Ocinara lewinae, Oenetus paradiseus, Opsirhina lechrioides, Piloprepes aemulella, Planotortrix excessana, Porela vetusta, Pseudalcis trispinaria, Pseudocoremia suavis, Pyralis ocellaris, Pyrgotis plagiatana, Sibine diplocyma, Sphaerelictis hepialella, spodoptera littoralis, Strepsicrates holotephras, S rhothia, Suana concolor, Teara contraria, Tortrix dinota, Trachydora musaea, Trichanua mejanesi, Trictena argentata, Trigonocyttara clandestine, Wingia aurata, Xanthodule semiochrea. Orthoptera. Brachytrupes membranaceus, B. portenosus, Caedicia simplex, Eyprepocnemis plorans, Gryllotalpa africana, Gymnogryllus erythrocephalus, G. humeralis, Kraussaria angulifera, Valanga irregularis. Phasmida. Acanthoxyla spp., Didymuria violescens, Extatosoma tiaratum, Podocanthus wilkinsoni. Aves. Calyptorhynchus funereus, C. magnificus. Mammalia. Cephalophus rufilatus, Eidolon helvum, Hystrix africaeaustralis, Lepus nigricollis, Mus musculus, Oryctolagus cuniculus, Papio ursinus, Pedetes cafer, Potamochoerus porcus, Raphicerus campestris, Strepsiceros strepsiceros, Sylvicapra, grimmia, Syncerus caffer, Thryonomys swinderianus, Thylogale thetis, Tragelaphus scriptus, Wallabia bicolor, W. dorsalis, W. rufogrisca. Castillo-Borboran (1981) discusses biotic problems with the nursery, "Pathogenic fungi, insects and other injurious agencies can cause problems. Leaf diseases including mildews and moulds can also spread quickly, hence, treatment with Benlate spray or dusting with a sulphur powder can provide satisfactory control. It was found better to prevent fungal problems through adequate ventilation, heat sterilization of the potting mixes, and good hygiene rather than fungicides. Pyrethrin-derived sprays and dusting powders, which are not toxic to man, have been found most useful in controlling many insect pests, particularly aphids, 2 to 3 months after transplanting." Though described as aeroallergenic, eucalyptus is mostly pollinated by insects (Agriculture Handbook No. 450).


Complete list of references for Duke, Handbook of Energy Crops
Last update Tuesday, January 6, 1998 by aw