Deguelia malaccensis (Benth.) Blake
Derris cuneifolia malaccensis Benth.
Derris malaccensis (Benth.) Prain
Derris montana Benth.
Derris pachycarpa Merr.
Derris caudata Backer
Derris danauensis Backer
Paraderris montana is a climbing shrub, producing stems 15 metres long or more[
]. The woody stems twine into other vegetation for support[
A lesser source of the insecticide rotenone, the roots are harvested from wild and cultivated plants for use as a fish poison and insecticide[
]. The plant is sometimes cultivated, mainly in Malaysia, Borneo and India, less frequently also in other countries of tropical Asia, Tonga and the West Indies[
]. Most widespread is the cultivar 'Sarawak erect'[
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.
Southeast Asia - Bangladesh, Myanmar, Thailand, Malaysia, Indo-China, Indonesia, New Guinea.
Riverine rain forest, at elevations up to 250 metres[
|Other Uses Rating||
|Cultivation Status||Cultivated, Wild
A plant of the moist tropics, where it is found at elevations up to 1,580 metres. It grows best in areas where annual daytime temperatures are within the range 22 - 30°c, but can tolerate 20 - 34°c[
]. It prefers a mean annual rainfall in the range 1,800 - 2,000mm, but tolerates 1,500 - 2,500mm[
Succeeds in full sun and in light shade[
]. Succeeds in a wide range of moist but well-drained soils of low to medium fertility[
]. Prefers a pH in the range 5.5 - 6.5, tolerating 4.5 - 8.5[
Toxicity of the root is usually highest 19 - 27 months after planting and at this state the roots are harvested[
]. In some areas 15 months of growth is sufficient[
Plants do not produce seed in the first 30 months after planting[
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 plant is grown in rubber, cacao, kapok, coffee and tea plantations, where it can provide shade, enrich the soil and provide organic matter[
The dried, powdered root contains rotenone is widely used as an insecticide[
]. Rotenone is effective against a range of horticultural pests, such as aphids and caterpillars, and also against external body parasites like ticks, lice, fleas and flies. It is reported to be ineffective against bedbugs, cockroaches, scale insects and red spiders.[
The content found in the roots is less than that found in Derris elliptica, but the content of other toxic compounds is higher[
The flexible stems make good cordage[
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