Genius & Specie: Agathosma - 150 species in genius Agathosma mostly found in the Western Cape
2 commercial species
• Agathosma betulina
• Agathosma crenulata
Agathosma from Greek – Agathos meaning pleasant and osme meaning smell.
Agathosma betulina has a natural distribution limited to the mountains of the Cederberg, Olifantsrivier and Piketberg.
Two chemotypes have been recognised within the species:
• Diosphenol chemotype (high in diosphenols, low in isomenthones), found further north in the mountain surrounding Citrusdal and on the Cederberg mountains.
• Isomenthone chemotype (high in isomenthones, low in diosphenols) found more southerly only in the Piketberg Mountains.
Agathosma crenulata has a natural distribution limited to the southerly mountain ranges of the Cape. It has similar characteristics to Agathosma betulina but contains a much higher pulegone content.
Agathosma betulina x crenulata (hybrid buchu)
Due to many taxonomic similarities between betulina and crenulata and poor access to GC analyses some confusion about the identity of plant and seed material occurred in the past. This led to the cultivation of both species in close proximity to each other, which led to the hybrid species. The degree of hybridization and also the composition of the oil various. It is interesting to note that some naturally occurring hybrids are found in regions in which both betulina and crenulata are found in nature (Porterville and Tulbagh).
The volatile oils accumulates and is contained in large circular cells under the surface of the leaf. Betulina yields are higher than crenulata.
The important components of buchu oil are:
• Limonene –
• Menthone -
• c- Mercaptone