Introduction

Kanna (Sceletium tortuosum) has been used for centuries by indigenous communities in southern Africa. Scientific and ethnobotanical studies have shown that alkaloid content varies among different plant tissues, influencing the characteristics historically associated with the plant. Understanding which parts to harvest and how to prepare them is valuable for research, botanical study, and educational purposes.

Alkaloid Distribution in Kanna (Dry Weight Basis)

The primary alkaloids found in Kanna are mesembrine, mesembrenone, and delta-7-mesembrenone. Their concentrations differ depending on the plant part. The values below are reported as dry weight percentages (DW), which is the standard used in phytochemical research.

This distribution can help guide harvesting decisions depending on which alkaloids are of interest for study.

How to Harvest Kanna

1. Harvesting Stems and Leaves Only

This method allows the plant to regrow for future harvests and tends to produce a more mesembrine-rich profile. Leave the final third of the growth closest to the crown intact to reduce stress and maintain plant vigor.

2. Harvesting the Entire Plant

This traditional method yields higher proportions of mesembrenone and delta-7-mesembrenone, but it results in the loss of the plant. When harvesting the entire plant, gently remove the root system to maximize the amount of material collected.

3. Use Clean Cutting Tools

Always use clean, sharp tools to minimize contamination and reduce unnecessary damage to plant tissues. This is important for both selective and whole-plant harvests.

4. Wash Plant Material Thoroughly

Rinse harvested material thoroughly, changing the water as needed until all visible debris and contaminants have been removed.

Preparation Methods

Once harvested, plant material can be prepared in a few different ways:

• Crushing and Drying: Breaking down the plant material through crushing and allowing it to sit for approximately 24 hours before drying has been reported to produce a desirable alkaloid profile while maintaining good alkaloid concentrations.
• Traditional Fermentation: Historically, Kanna material was often fermented. Fermentation can alter the alkaloid profile and other physical characteristics of the plant material. Traditional accounts generally describe crushing the material and leaving it in a sealed container in the sun for approximately one week, with occasional stirring before drying. However, this approach can easily result in undesirable fermentation. Modern methods often involve crushing the material, partially drying it to approximately 60% relative humidity, and then fermenting it for several days under more controlled conditions.
• Direct Drying: Leaves and stems are typically dried at moderate temperatures to minimize alkaloid degradation. Roots generally require a longer drying period because of their denser tissue structure.

These preparation techniques are described for educational and research purposes only and should not be interpreted as instructions for consumption.

Conclusion

Sceletium tortuosum (Kanna) exhibits variable alkaloid concentrations depending on plant part, age, and harvesting method. Understanding these differences is important for research, botanical study, and the preservation of traditional knowledge. Selective harvesting, clean techniques, and careful preparation can help produce high-quality plant material for study while supporting sustainable cultivation practices.

References & Further Reading

• Faber RJ, Laubscher CP, Rautenbach F, Jimoh MO (2020). Variabilities in alkaloid concentration of Sceletium tortuosum in response to different soilless growing media and fertigation regimes in hydroponics. PubMed Central — PMC7670209.
• South African National Biodiversity Institute (SANBI): Sceletium tortuosum species profile.
• Gericke, Brendler, and others. Reviews on Sceletium phytochemistry and traditional use.