Tea from Southern Africa! Looking at samples of my tea collection with Foldscope actually resembles a throwback to looking at your ‘Hortus siccus’ – a collection of dried plants from a herbarium, like plant explorers and collectors of old. I first looked at Rooibos (red bush) tea – Aspalathus linearis – a species endemic to a small region on the west coast of Southern Africa and used as herbal remedy by indigenous Khoi San tribes since prehistoric times. It has globally become a popular tea for its anti-oxidant properties, anti-allergens, also used in ointments, facial products and even as baby food substitute. With Foldscope I could see the fine narrow leaves and twigs that are harvested for drying and fermentation. The leaves are quite thick to penetrate with the light module, but I did could see individual leaf cells and woody elements.
(1) Aspalathus linearis
Second I looked at Honeybush tea (Cyclopia species) which are endemic to the mountains on the southern coast of South Africa. Both leaves and flowers are dried and fermented, and have a distinctive sweet honey flavor, which does not go bitter even when steeped for hours. The plant was noted in botanical literature from 1705, the first settlers used it as substitute for black tea while the indigenous Khoi San used it as cough remedy. With Foldscope I could see leaves with individual cells similar to Rooibos.
(2) Cyclopia maculata, sessiliflora or genistoides
Third I took some dried Buchu leaves that I normally mix with Rooibos and/or Honeybush for a refreshing drink before bedtime, reminding me of nature and camping in the bush. Buchu leaves (Agathosma betulina) are known for their medicinal properties and even mixed with brandy for stomach ailments, by explorers and settlers. Foldscope highlighted the leaves with trichomes, and zooming in on the leaf surface I could see individual cells and surface glands that produce the essential oils like mercaptone, menthone, limonene, menthone and pulegone used in aromatherapy.
(3) Agathosma betulina
Again, a delightful journey of exploration with Foldscope!