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Promoting the conservation and use of underutilized and neglected crops. 1.
Physic nut
Jatropha curcas L.
Joachim Heller
ernational Plant Genetic Resources Institut



Physic nut. Jatropha curcas L.
The International Plant Genetic Resources Institute (IPGRI) is an autonomous international
scientific organization operating under the aegis of the Consultative Group on Interna-
tional Agricultural Research (CGIAR). The international status of IPGRI is conferred un-
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advance the conservation and use of plant genetic resources for the benefit of present and
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participating organizations.
Heller, Joachim. 1996. Physic nut. Jatropha curcas L. Promoting the conservation and use
of underutilized and neglected crops. 1. Institute of Plant Genetics and Crop Plant Re-
search, Gatersleben/ International Plant Genetic Resources Institute, Rome.
ISBN 92-9043-278-0
Via delle Sette Chiese 142
Corrensstraße 3
00145 Rome
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© International Plant Genetic Resources Institute, 1996

Promoting the conservation and use of underutilized and neglected crops. 1.
1. Introduction
2. Names of the species and taxonomy
3. Botanical description
4. Origin and centre of diversity
5. Properties
6. Uses
Whole plant and food/fodder
Plant protectant and molluscicide
Technical uses
Diesel fuel
Other uses
7. Genetic resources
Existing genetic variation
Conservation of physic nut
8. Breeding
Breeding objectives
Breeding method
Selection based on provenance trials
9. Production areas
10. Ecology
11. Agronomy
Growth and development
Propagation methods
Pests and diseases
12. Limitations of the crop
13. Prospects
14. Research needs
Appendix I. Research contacts, centres of crop research, breeding
and plant genetic resources of physic nut
Appendix II. Publications of Proyecto Biomasa, DINOT/UNI,

Physic nut. Jatropha curcas L.
The information contained in this monograph was partly compiled during the produc-
tion of my PhD thesis under the supervision of Prof. Dr D. Leihner at the University of
Hohenheim, Stuttgart. I am particularly grateful to him and to the Deutsche Gesellschaft
für Technische Zusammenarbeit (GTZ) for initiating and financing the research project
at that time. I am indebted to all my coworkers at the University of Hohenheim, the GTZ
in Senegal and the INIA, Cape Verde, and I wish to acknowledge my appreciation of
their support and cooperation, and for all our discussions.
I thank Prof. Bijan Dehgan, Dr Jan Engels, Prof. José Mendes Ferrão, Mr Nikolaus
Foidl, Mr Jürgen Gliese, Dr Phil Harris, Mr Reinhard Henning, Dr Norman Jones, Dr
Bhag Mal, Mr Stefan Peterlowitz, Prof. Lucia Ramirez, Dr Jozef Turok and Prof. Michael
Wink for their critical review of the manuscript.
I thank Prof. B. Dehgan and the Annals of the Missouri Botanical Garden for their
permission to reprint Figure 1, and Mr R. Henning for providing several photographs.

Promoting the conservation and use of underutilized and neglected crops. 1.
Humanity relies on a diverse range of cultivated species; at least 6000 such species are
used for a variety of purposes. It is often stated that only a few staple crops produce the
majority of the food supply. This might be correct but the important contribution of many
minor species should not be underestimated. Agricultural research has traditionally fo-
cused on these staples, while relatively little attention has been given to minor (or
underutilized or neglected) crops, particularly by scientists in developed countries. Such
crops have, therefore, generally failed to attract significant research funding. Unlike most
staples, many of these neglected species are adapted to various marginal growing condi-
tions such as those of the Andean and Himalayan highlands, arid areas, salt-affected soils,
etc. Furthermore, many crops considered neglected at a global level are staples at a na-
tional or regional level (e.g. tef, fonio, Andean roots and tubers etc.), contribute consider-
ably to food supply in certain periods (e.g. indigenous fruit trees) or are important for a
nutritionally well-balanced diet (e.g. indigenous vegetables). The limited information avail-
able on many important and frequently basic aspects of neglected and underutilized crops
hinders their development and their sustainable conservation. One major factor hamper-
ing this development is that the information available on germplasm is scattered and not
readily accessible, i.e. only found in ‘grey literature’ or written in little-known languages.
Moreover, existing knowledge on the genetic potential of neglected crops is limited. This
has resulted, frequently, in uncoordinated research efforts for most neglected crops, as
well as in inefficient approaches to the conservation of these genetic resources.
This series of monographs intends to draw attention to a number of species which have
been neglected in a varying degree by researchers or have been underutilized economically.
It is hoped that the information compiled will contribute to: (1) identifying constraints in and
possible solutions to the use of the crops, (2) identifying possible untapped genetic diversity
for breeding and crop improvement programmes and (3) detecting existing gaps in available
conservation and use approaches. This series intends to contribute to improvement of the
potential value of these crops through increased use of the available genetic diversity. In
addition, it is hoped that the monographs in the series will form a valuable reference source
for all those scientists involved in conservation, research, improvement and promotion of
these crops.
This series is the result of a joint project between the International Plant Genetic
Resources Institute (IPGRI) and the Institute of Plant Genetics and Crop Plant Research
(IPK). Financial support provided by the Federal Ministry of Economic Cooperation
and Development (BMZ) of Germany through the German Agency for Technical Coop-
eration (GTZ) is duly acknowledged.
Series editors:
Dr Joachim Heller, Institute of Plant Genetics and Crop Plant Research (IPK)
Dr Jan Engels, International Plant Genetic Resources Institute (IPGRI)
Prof. Dr Karl Hammer, Institute of Plant Genetics and Crop Plant Research (IPK)

Physic nut. Jatropha curcas L.
1. Introduction
The use of trees and shrubs in arid and semi-arid regions is of vital importance for the
human population in developing countries (Ben Salem and Palmberg 1985). The ex-
haustive exploitation of these resources in conjunction with droughts, especially in the
Sahel, has caused an alarming reduction in tree cover. This has resulted in increased
desertification, soil erosion caused by wind and water, and droughts and floods as well
as reduced water supply and decreasing soil fertility. Trees also play an important role
in the CO cycle of the earth as they assimilate carbon dioxide.
Traditionally, shrubs (and trees) serve many purposes. Le Houérou (1989) distin-
guished 13 groups according to how they are used:
1. food and drink for humans
2. browse for livestock and wildlife
3. beekeeping and honey production
4. source of energy – firewood and charcoal
5. building and fencing material
6. fibre for cloth, rope and handicrafts
7. tools for agriculture and cottage industry
8. handicraft, art and religious objects
9. dye and tanning
10. drugs, medicinal and veterinary uses
11. shade and shelter for plants, animals and humans (‘palaver’ trees)
12. protection against erosion, maintenance of soil fertility and productivity
13. water storage.
Attempts are now being made to promote the cultivation of crops previously
grown only regionally or to a low extent. Comprehensive surveys exist, especially of
crops which adapt well to arid and semi-arid conditions (Davis et al. 1983; Weiss
1989). In order to identify interesting plant species, not only for use as raw material
in industry but also as an energy source, a number of comprehensive surveys have
been carried out in the United States of America (Nielsen et al. 1977; Buchanan et al.
1978; Wang and Hufman 1981; McLaughlin and Hoffmann 1982; Carr et al. 1985).
Plant species which can be processed to provide a diesel fuel substitute have
captured the interest of scientists more in temperate than in tropical zones. In this
plant category, the following properties of the tropical physic nut (Jatropha curcas L.,
Euphorbiaceae) have won over the interest of various development agencies: it
adapts well to semi-arid marginal sites, its oil can be processed for use as a diesel
fuel substitute and it can be used for erosion control. Although the physic nut is of
Mexican and Central American origin, it is cultivated in many other Latin American,
Asian and African countries as a hedge and it was an important export product from
the Cape Verde Islands during the first half of this century. The aim of this mono-
graph is to make information more easily available to those interested in the poten-
tial uses and the genetic resources of the physic nut.

Promoting the conservation and use of underutilized and neglected crops. 1.
2. Names of the species and taxonomy
The Euphorbiaceae family comprises approximately 8000 species, belonging to 321 gen-
era. According to Leon (1987), Mabberley (1987) and Rehm and Espig (1991), crops of
economic importance in this large family are:
q roots
cassava (Manihot esculenta)
q rubber
Hevea (Hevea brasiliensis)
q fruits
emblic, Otaheite gooseberry (Phyllanthus spp.), tjoopa,
rambai, mafai (Baccaurea spp.), Chinese laurel (Antidesma
, Ricinodendron spp.
q nuts
tacay (Caryodendron orinocense)
q vegetables
katuk (Sauropus androgynus), chaya (Cnidoscolus chayamansa)
q oil
castor (Ricinus communis), tung trees (Aleurites spp.),
Chinese tallow tree (Sapium sebiferum), physic nut (Jatropha
q hydrocarbon
Euphorbia spp.
q medicinal
Croton spp., Jatropha spp.
The genus Jatropha belongs to tribe Joannesieae of Crotonoideae in the Euphorbiaceae
family and contains approximately 170 known species. Dehgan and Webster (1979) re-
vised the subdivision made by Pax (1910) and now distinguish two subgenera (Curcas
and Jatropha) of the genus Jatropha, with 10 sections and 10 subsections to accommodate
the Old and New World species. They postulated the physic nut (Jatropha curcas L. [sect.
Curcas (Adans.) Griseb., subg. Curcas (Adans.) Pax]) to be the most primitive form of the
Jatropha genus. Species in other sections evolved from the physic nut or another ances-
tral form, with changes in growth habit and flower structures. Hierarchical cluster analy-
sis of 77 New World Jatropha species showed for the most part concordance with Dehgan
and Webster’s (1979) infrageneric classification (Dehgan and Schutzman 1994). Figure 1
shows the phenogramme of Neotropical Jatropha species. Further cladistic analysis sup-
ported Dehgan and Webster’s (1979) evolutionary model of the genus Jatropha.
The following are other species that belong to the section Curcas: J. pseudo-curcas
Muell. Arg., J. afrocurcas Pax, J. macrophylla Pax & Hoffm., J. villosa Wight (syn.: J. wightiana
Muell. Arg.), J. hintonii Wilbur, J. bartlettii Wilbur, J. mcvaughii Dehgan & Webster and J.
yucatanensis Briq. McVaugh (1945) considered J. yucatanensis to be a synonym of J. curcas.
One species, J. villosa, is of Indian origin. Two, J. afrocurcas and J. macrophylla, are of East
African origin, whereas all the other species in this section are native to the Americas.
Although most of the Jatropha species are native to the New World, approximately 66
species are native to the Old World. Dehgan and Webster (1979) offered a key to the
infrageneric taxa but this should not be considered as final since information is still lack-
ing on many species. No complete revision of the Old World Jatropha exists. Hemming
and Radcliffe-Smith (1987) revised 25 Somalian species, all of the subgenus Jatropha, and
placed them in six sections and five subsections. Jatropha multifida L. and J. podagrica
Hook. of section Peltatae, J. integerrima of section Polymorphae, and J. gossypiifolia of sec-
tion Jatropha are well known and cultivated throughout the tropics as ornamental plants.
Linnaeus (1753) was the first to name the physic nut Jatropha curcas L. according to

Physic nut. Jatropha curcas L.
Fig. 1. Phenogramme of 77 Neotropical Jatropha species from 32 characters, using F.J. Rohlf’s NTSYS-
pc programme. Infrageneric designations are from Dehgan and Webster (1979) (reprinted with
permission from Dehgan and Schutzmann 1994).

Promoting the conservation and use of underutilized and neglected crops. 1.
the binomial nomenclature of “Species Plantarum” and this is still valid today. Accord-
ing to Dehgan and Webster (1979) and Schultze-Motel (1986), synonymous names of the
physic nut are:
Curcas purgans Medik., Ind. Pl. Hort. Manhem. 1: 90. 1771; Baill. Étud. Gen. Euphorb.
314, 1858.
Ricinus americanus Miller, Gard. Dict. ed. 8. 1768.
Castiglionia lobata Ruiz & Pavon, Fl. Peruv. Prodr. 139, t. 37. 1794.
Jatropha edulis Cerv. Gaz. Lit. Mex. 3: supl. 4. 1794.
J. acerifolia Salisb., Prodr. Chapel Allerton 389. 1796.
Ricinus jarak Thunb., Fl. Javan. 23. 1825.
Curcas adansoni Endl., ex Heynh. Nomencl. 176. 1840.
Curcas indica A. Rich. in Sagra, Hist. Fis. Pol. Nat. Cuba 3: 208. 1853.
?Jatropha yucatanensis Briq. Ann. Cons. Jard. Genève 4: 230. 1900; Standley, Contr.
U.S. Nat. Herb. 23: 640. 1923; McVaugh, Bull. Torrey Bot. Club 72: 35. 1945.
Curcas curcas (L.) Britton & Millsp., Bahama Fl. 225. 1920.
The genus name Jatropha derives from the Greek iatrós (doctor) and trophé (food)
which implies medicinal uses. According to Correll and Correll (1982), curcas is the
common name for physic nut in Malabar, India.
Numerous vernacular names exist for the physic nut: physic nut, purging nut (En-
glish); pourghère, pignon d’Inde (French); purgeernoot (Dutch); Purgiernuß, Brechnuß
(German); purgueira (Portuguese); fagiola d’India (Italian); dand barrî, habel meluk
(Arab); kanananaeranda, parvataranda (Sanskrit); bagbherenda, jangliarandi, safed
arand (Hindi); kadam (Nepal); yu-lu-tzu (Chinese); sabudam (Thailand); túbang-bákod
(the Philippines); jarak budeg (Indonesia); bagani (Côte d’Ivoire); kpoti (Togo); tabanani
(Senegal); mupuluka (Angola); butuje (Nigeria); makaen (Tanzania); piñoncillo (Mexico);
coquillo, tempate (Costa Rica); tártago (Puerto Rico); mundubi-assu (Brazil); piñol (Peru)
and pinón (Guatemala) (Münch 1986; Schultze-Motel 1986).

Physic nut. Jatropha curcas L.
3 Botanical description
The physic nut is a drought-resistant species which is widely cultivated in the tropics as
a living fence. Many parts of the plants are used in traditional medicine. The seeds,
however, are toxic to humans and many animals. Considerable amounts of physic nut
seeds were produced on Cape Verde during the first half of this century, and this consti-
tuted an important contribution to the country’s economy. Seeds were exported to Lisbon
and Marseille for oil extraction and soap production. Today’s global production is, how-
ever, negligible.
The physic nut, by definition, is a small tree or large shrub which can reach a height
of up to 5 m. The plant shows articulated growth, with a morphological discontinuity at
each increment. Dormancy is induced by fluctuations in rainfall and temperature/light.
The branches contain latex. Normally, five roots are formed from seedlings, one central
and four peripheral. A tap root is not usually formed by vegetatively propagated plants
(Kobilke 1989). The physic nut has 5 to 7 shallow lobed leaves with a length and width
of 6 to 15 cm, which are arranged alternately. Inflorescences are formed terminally on
branches and are complex, possessing main and co-florescences with paracladia. Bo-
tanically, it can be described as a cyme. The plant is monoecious and flowers are uni-
sexual; occasionally hermaphrodite flowers occur (Dehgan and Webster 1979). Ten sta-
mens are arranged in two distinct whorls of five each in a single column in the
androecium, and in close proximity to each other. In the gynoecium, the three slender
styles are connate to about two-thirds of their length, dilating to massive bifurcate stig-
mata (Dehgan and Webster 1979).
Pollination of the physic nut is by insects. Dehgan and Webster (1979) believe that it
is pollinated by moths because of “its sweet, heavy perfume at night, greenish white
flowers, versatile anthers and protruding sexual organs, copious nectar, and absence of
visible nectar guides”. When insects are excluded from the greenhouse, seed set does
not occur without hand-pollination. The rare hermaphrodite flowers can be self-polli-
nating. During field trials, Heller (1992) observed a number of different insects that
visited flowers and could pollinate. In Senegal, he observed that staminate flowers open
later than pistillate flowers in the same inflorescence. To a certain extent, this mecha-
nism promotes cross-pollination. Münch (1986) did not observe this chronological order
in Cape Verde. It seems that the mechanism is influenced by the environment. After
pollination, a trilocular ellipsoidal fruit is formed. The exocarp remains fleshy until the
seeds are mature. The seeds are black, 2 cm long and 1 cm thick. The caruncle is rather
small. Wiehr (1930) and Droit (1932) described the microscopical anatomy of the seeds
in detail, while Singh (1970) described that of fruits. Gupta (1985) investigated the
anatomy of other plant parts. The physic nut is a diploid species with 2n = 22 chromo-
somes. Relevant parts of the plant are shown in Figures 2 and 3.

Document Outline

  • Contents
  • Acknowledgements
  • Foreword
  • 1. Introduction
  • 2. Names of the species and taxonomy
  • 3 Botanical description
  • 4 Origin and centre of diversity
  • 5 Properties
  • 6 Uses
  • 7 Genetic resources
  • 8 Breeding
  • 9 Production areas
  • 10 Ecology
  • 11 Agronomy
  • 12 Limitations of the crop
  • 13 Prospects
  • 14 Research needs
  • Bibliography
  • A. Further reading (not cited in the text)
  • B. Sources for distribution of physic nut
  • Appendix I. Research contacts, centres of crop research, breeding and
  • Appendix II. Publications of Proyecto Biomasa, DINOT/UNI, Nicaragua.