There is considerable confusion over the correct identity of this plant. This record is based on Ecocrop[
], which uses the botanical name Lonchocarpus nicou. In some other accounts L. Nicou is seen as a synonym of either Derris nicou (Aubl.) J.F. Macbr.; Lonchocarpus utilis A.C. Sm.; Derris utilis (A.C.Sm.) Ducke; or Deguelia utilis (A.C.Sm. emendavit A.M.G.Azevedo) A.M.G.Azevedo. It is possible, in fact probable, that more than one species is involved here, though they are all likely to have similar uses. I am fairly certain that Deguelia utilis is a distinct and valid species, so a record has also been drawn up for that plant[
]. The range given below for this species is almost certainly inaccurate[
Derris nicou (Aubl.) J.F.Macbr.
Robinia nicou Aubl.
Common Name: Barbasco
Barbasco is an erect, evergreen shrub or a climbing plant producing several woody stems from its base that clamber into other plants for support.
This plant is an important source of the organic insecticide rotenone (the active ingredient in derris). The plant was first cultivated in S. America by the native people before the arrival of the Europeans. They used it as a fish poison and to kill ants. It is now cultivated on a fairly large scale in parts of tropical S. America, the rotenone being exported to various other countries throughout the world[
The plant contains rotenone and has been used traditionally as a fish poison[
] - the rotenone kills or stuns the fish making them easy to catch, but the fish remain perfectly edible for mammals. Rotenone is classified by the World Health Organization as moderately hazardous. It is mildly toxic to humans and other mammals, but extremely toxic to many insects (hence its use as an insecticide) and aquatic life, including fish. This higher toxicity in fish and insects is because the lipophilic rotenone is easily taken up through the gills or trachea, but not as easily through the skin or the gastrointestinal tract. The lowest lethal dose for a child is 143 mg/kg, but human deaths from rotenone poisoning are rare because its irritating action causes vomiting. Deliberate ingestion of rotenone, however, can be fatal.
The compound decomposes when exposed to sunlight and usually has an activity of six days in the environment.
Northern S. America - Brazil, Peru, Ecuador, Colombia, Venezuela and the Guyanas.
|Other Uses Rating||
|Cultivation Status||Cultivated, Wild
A plant of the moist tropics where it is found at elevations from near sea level to 1,340 metres[
]. It grows best in areas where the mean annual temperature ranges from 23 - 32°c, but can tolerate 15 - 41°c[
]. It prefers a mean annual rainfall in the range 2,300 - 2,700mm, but tolerates 2,000 - 3,100mm, and is found in areas with all year round rainfall and also where there is a distinct dry season[
Succeeds in full sun and in dappled shade[
]. Young plants benefit from some shade, while older plants make more vigorous growth in full light[
]. Grows best in a medium soil that is rich in organic matter, but also succeeds in heavier soils[
]. Prefers a pH in the range 5.5 - 6.5, but can tolerate 5 - 7[
The first harvest of the stems can be made when the plants are 2 - 3 years old from cuttings[
The roots are usually harvested during the dry season[
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby.
The plants are grown in small gardens or fields, often in crop mixtures with cassava, beans or corn[
The roots contain 0.75 - 1% rotenone, which can be used as an insecticide[
]. The rotenone content of the roots (ranging from 5 - 15%, with some clones yielding 20%) is greater than that of the related Lonchocarpus urucu (which ranges from 4 - 11%). This, however, is somewhat balanced by the fact that the overall yield of roots is higher for Lonchocrpus urucu[
Seed - seldom produced by the plants[
If you have any useful information about this plant, please leave a comment. Comments have to be approved before they are shown here.