B. serrata Roxb. (Indian Frankincense)
Indian name: salai guggul, gugal
B. serrata grows in the drier climates of Northern India. This is the Frankincense that is primarily used in making Asian varieties of incense. It is also the Frankincense used in Ayurvedic medicine.
Frankincense is the first thing that comes to mind in the minds of most Westerners when you mention incense. There is still confusion about varieties and species of Frankincense.
The major fragrance use is for burning as incense in religious ceremonies. Small amounts of resin are distilled to yield volatile oils and these have their own characteristic, balsamic odors, which find use in perfumery. Solvent extracts are also prepared and both resinoids and absolutes are used as fixatives in perfumes.
The resins are sorted and graded according to size, color and state of cleanliness before being bagged for export. In Somalia, there are up to seven grades of maidi, (olibanum from Boswellia frereana) and three grades of beyo (olibanum from B. sacra). The larger, paler lumps used for chewing are more highly valued than the smaller and darker colored pieces and the powder and siftings.
THULIN and WARFA (1987), however, have concluded that B. carteri is simply a variable form of B. sacra and should not be afforded separate species status. B. frereana is a distinct and fairly uniform species, easily distinguished from B. sacra.
Boswellia sacra Flückiger (syn. B. carteri Birdw.)
B. sacra is a small tree, occasionally up to 8 m tall, branching from e base. It occurs in South Yemen, Oman and northern Somalia. (Those who regard B. sacra and B. carteri as distinct species identify the former as growing in Arabia and the latter in Somalia.)
B. frereana Birdw.
B. frereana grows to a similar height as B. sacra but is restricted to northern Somalia.