A shampoo tree
One of the most common trees around Dokmai Garden is ‘ton mi’, Litsea glutinosa (Lauraceae). An English name is Indian laurel, and indeed it is a member of the laurel family. In Chiang Mai in northern Thailand it is a deciduous tree during the hottest time of the year (March-April), but right now it is in blossom. The flowers are yellow and carry a fragrance resembling honey or bee’s wax. Many insects, especially flies, like to pollinate this tree. The result of the pollination are small black fruits which attract birds at the end of the rainy season. The fruits are edible but not tasty, quite sharp actually. Ketsanee’s hairdresser in the village told Ketsanee that most Thai people nowadays cut them down, which is a pity since this tree was once the source of shampoo making:
Pound some leaves in water to produce a viscous fluid used as a shampoo. Sometimes water used to clean the rice was used. The leaves contain saponin which gives a foam, and polysaccharides which makes the fluid thick. The saponins protect the leaves from insects and fungi, so adding it to your shampoo may help you with scalp infections. One could add fragrant flowers or peel from makrut lime (Citrus hystrix, Rutaceae) to create a fragrance, and various plant dyes.
The Indian laurel can also be used for liquid soap making:
About 500 g of ash from cooking is collected and boiled in one litre of water. Filter using an old shirt and let the collected lye (KOH) settle over night to remove the last ash particles as a sediment. The lye is needed for saponification, i.e. to break down fat into fatty acids and glycerin. The soap is a salt of a fatty acid. Add 30 g Litsea glutinosa seed oil (lauric acid 85% and oleic acid 15%) to the lye and boil for ten minutes. Add makrut lime for fragrance and to lower the pH. Use red cabbage, eggplant peel or blue chili or blue tomato as a pH indicator (if the anthocyanins derived from boiling these vegies turn red=acid, purple=neutral, blue or green=alkaline). Add a dye of your choice while the soap is still hot. If you need to thicken the liquid, add any thickener including the leaves of the Indian laurel or Aloe vera.
To make a firm soap, exchange the wood ash lye with soda lye (NaOH), but that lye has to be bought unless you have access to ash of seaside soda plants (Salsola and Halogeton, Amaranthaceae spp. in Europe, various mangroves in Asia and South America ).
The Indian laurel was once a useful tree for making shampoo and medicine, now degraded to a nameless shrub, yielding to South American ornamentals.