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Illustrated proposal for a guideline on the commercial collection of the medicinal plant

 Harpagophytum procumbens from the environment

(GHP / GcoIP, Good Harvesting/Collecting Practice for Medecinal Plant-Material)


Text of the Guideline



Sustainable harvest in semi-wild populations of Harpagophytum procumbens in the Kalahari of South Africa.




Medicinal uses of Devil’s Claw

The secondary root tubers of Harpagophytum procumbens are used as herbal medicine in Europe for rheumatic diseases. The quality must be in accordance to several European pharmacopoeias. Devil’s Claw is very famous especially in Germany and therefore the demand of raw material is increasing.


Legal framework

a) Nature conservation

Because of over-exploitation of Harpagophytum in some regions in Southern Africa there was a proposal to include Harpagophytum in the endangered species list according to Washington Convention during CITES meeting in Gigiri (Kenya) in April 2000. After that it is necessary for German importers to get export licenses from the local nature conservation authorities and import certificates from the German Federal Agency for Nature Conservation. To obtain certificates according to international rules endangered species must be harvested from cultivations or collected in semi-wild populations by sustainable methods under supervision of nature conservation services.

b) Medicinal product regulations

Herbal medicines must be produced according to Good Manufacturing Practice (GMP) published by WHO. Raw plant material as a staring material for pharmaceutical production has to be produced according to Good Agricultural Practice (GAP) if the medicinal plant is cultivated on farms. For wild harvested medicinal herbs recently a proposal was published for Good Harvesting/Collection Practice for Medicinal Plant-Material (GHP/GCoIP).


The object of this topic is the sustainable harvest in semi-wild populations of Harpagophytum procumbens  in communities in the Kalahari of South Africa in agreement to these rules.


Publications used to prepare this paper:

G.Harnischfeger, Salzgitter, Proposal GHP 1997

E.Schneider, Medicinal Plant Conservation Vol 4, Dec. 1997

B.Hachfeld, Köln, personal communication 1999

S.Leloup, The grapple plant project, NIR Gabarone, Botswana 1984




Collecting Area

Description of the digging / collecting area and exact range definition:

Detailled maps with collecting areas

Marking this years areas for digging/collecting on the maps.

Definition of protected areas for regeneration. If possible the collecting area is to divide in four quarters and harvesting takes place only in one quarter every year.


Collecting of data on ecological conditions of the collecting area and its natural habitats:


Actual weather conditions during growing and harvesting seasons.

Soil type

Specifics influencing the quality (e.g. other plants at the same area as possible adulterants) (See figure)


Research in population dynamics to avoid over-exploitation: (See figure)

Transectwalks to count individuals of Harpagophytum: (E.Schneider, 1997; B.Hachfeld, Köln, personal communication 1999)

Walk along transects of the area Harpagophytum occurs and count the plant number along that transect of one meter width. Then calculate the total numbers by extrapolating the counted number to the total area.

Mapping of plots:  (S.Leloup 1984)

Mark an area of 100 to 200 meters and plot the individual plants of Harpagophytum and the main other plants occurring in that area on a sheet of paper. Then count the number of Harpagophytum plants on that map and calculate the total number by extrapolating the counted number to the total area.

Repeat counting every year before harvesting time.


Observe conditions of plants (growing conditions, insects feeding).

Note other plants in the same habitat. (See figure)


Protection of endangered species:

Collect only an amount depending on permits of official authorities.

Try to cultivate Harpagophytum near your house.


Documentation of all details of the collection area to be prepared for audits.



Harvesting Personnel

Extensive knowledge of the diggers about the identification or the plant to collect.

Distinguish between the medicinal plant and close relatives and adulterations.

Wait for optimum conditions for the time of harvesting.

Personal hygiene, ill and persons with skin disorders are not allowed to harvest.

Education process for diggers/collectors to enhance the knowledge of harvesting procedure. The figures in the annex may be used as a helpful tool.



Digging/Collecting Procedure

Appoint a responsible person for organization of digging/harvesting/collecting, correct identification of plants and compliance with rules.


Digging/collecting at time of optimum conditions. Best time to harvest is in April, when the seed pods are ripe. If the collecting area is divided in four quarters and harvesting takes place only in one quarter every year then the harvest is possible from October to April when the soil is wet and it is easy to dig. The earlier the tuber is replanted in the season, the better are their chances for survival.


Observe weather conditions.


Use of clean and adequate equipment.


Avoid mechanical damage of the collected plant material and especially of the primary root.


Enable the plant to regenerate and avoid devastation of the habitat:

Close the digging pits after harvesting. (See figure)

Replant the primary root (the mother of Harpagophytum tubers).

Collect fruits of Harpagophytum and distribute the seeds in the harvesting range to enhance the number of plants.


Store collected plants protected from any types of animals. Harpago tubers can be stored in a dry place before slicing and drying.


Education of the responsible persons to enhance knowledge.




Preperation of Fresh Plant Material

Wait for good weather conditions for slicing and drying.


Select during slicing adulterants and tubers destroyed by insects and tubers of red colour inside.


Use clean and appropriate tools:

Use only clean brush and drinking water for washing the tubers. (See figure)

For slicing harpago tubers only use stainless steel knifes. (See figure)

The cutting board must only be used for cutting of harpago tubers.


Clean the tools and be aware of hygienic conditions during preparation.



After preparing, the fresh material should be dried promptly


During drying the plant material must be protected from rainfall and dew.


Facilities for drying must be clean, well aerated and never be used for animal keeping.


Air drying in a thin layer on nets in a sufficient distance from ground to provide adequate air circulation. (See figure)


It is possible to dry the sliced tubers on the clean roof of the house under exposition to sunlight.


Avoid drying directly on the ground because of sand being blown on the fresh material.


Protect plants during drying from any types of animals.


For transportation of dried material use clean bags/containers and label properly. (See figure)



Packaging, Storage & Transportation

Screen dried material to separate discoloured pieces and contaminants (moulds, tubers of other plants). (See figure)


Waste should be separated carefully.


Dried material should be packed in clean containers and labelled properly.


Store the bags with dried material in well aerated warehouses never be used for animal keeping and avoid any contact with moist and rain. (See figure)


Before transportation clean the lorry/truck and be aware of proper equipment to avoid contamination and contact with rain or dust during transportation.


Documentation of all steps of the campaign by collecting organization or local buyer, signed by a responsible person and kept for 3 years. Add a short batch report to the exported material (type of material – Harpago tuber slixed, sustainable harvest/cultivated, collecting/cultivating area, community, harvest time, permit, amount, responsible exporter).  

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Last modified: Januarie 28, 2003