Agathosma
Agathosma is a genus of about 140 species of flowering plants in the family Rutaceae, native to the southern part of Africa. Common names include buchu, boegoe, bucco, bookoo, and diosma. Buchu formally denotes two herbal species, prized for their fragrance and medicinal use despite their toxicity. In colloquial use however, the term is applied to a wider set of fragrant shrubs or substitutes.
They are small shrubs and subshrubs, mostly with erect woody stems reaching tall, but low-growing and prostrate in some species. The leaves are usually opposite, ericoid, often crowded, simple, entire, from long. The flowers are produced in terminal clusters, diameter, with five white, pink, red or purple, petals.
Many of the species are highly aromatic, and the genus name means "good fragrance". Some species of the genus are used as herbal remedies.
Uses
Two species of Agathosma endemic to the Western Cape mountains of South Africa and colloquially referred to as "buchu" are cultivated on a commercial basis for their essential oils, Agathosma betulina and Agathosma crenulata. The leaves of Agathosma betulina have been used in traditional medicine. Bottled agathosma infusions were widely sold in English-speaking countries as "buchu tea" in the 1860s and 1870s.
Although demand declined in the 1880s, consumption has continued to the present day; as of 2012, bottled infusions continue to be prepared from agathosma leaves. In addition, traditional buchu tinctures can be prepared by placing leaves and stalks into brandy. "Buchu vinegar", prepared by steeping the leaves and stalks in vinegar, also is a traditional remedy used for example in compresses and also taken internally.
The essential oil is used in the manufacture of flavorings and perfume. There appear to be differences in people's perceptions of the smell, possibly determined genetically, rather than by familiarity or nurture. Some people find the smell to be repulsive, while most find it pleasantly herbal. This is not particularly unusual in reaction to the smells of many aromatic Karoo shrubs.
Selected species
A. abrupta PillansA. acocksii PillansA. acutissima DümmerA. adenandriflora Schltr.A. adnata PillansA. aemula Schltr.A. affinis Sond.A. alaris Cham.A. alligans I.WilliamsA. alpina Schltr.A. alticola Schltr. ex DümmerA. anomala E.Mey. ex Sond.A. apiculata E.Mey. ex Bartl. & H.L.Wendl.A. asperifolia Eckl. & Zeyh.A. barnesiae ComptonA. bathii PillansA. betulina PillansA. bicolor DümmerA. bicornuta R.A.DyerA. bifida Bartl. & H.L.Wendl.A. bisulca Bartl. & H.L.Wendl.A. blaerioides Cham.A. bodkinii DümmerA. capensis DümmerA. capitata Sond.A. cedrimontana DümmerA. cephalodes E.Mey. ex Sond.A. cerefolia Bartl. & H.L.Wendl.A. ciliaris DruceA. ciliata LinkA. clavisepala R.A.DyerA. collina Eckl. & Zeyh.A. concava PillansA. conferta PillansA. cordifolia PillansA. corymbosa G.DonA. craspedota E.Mey. ex Sond.A. crassifolia Sond.A. crenulata PillansA. decurrens PillansA. dentata PillansA. dielsiana Schltr. ex DümmerA. distans PillansA. divaricata PillansA. dregeana Sond.A. elata Sond.A. elegans Cham.A. eriantha Steud.A. esterhuyseniae PillansA. florida Sond.A. florulenta Sond.A. foetidissima Steud. – BokboegoeA. foleyana DümmerA. fraudulenta Sond.A. geniculata PillansA. giftbergensis E.PhillipsA. glabrata Bartl. & H.L.Wendl.A. glandulosa Sond.A. gnidiiflora DümmerA. gonaquensis Eckl. & Zeyh. – Gonaqua buchuA. hirsuta PillansA. hirta Bartl. & H.L.Wendl.A. hispida Bartl. & H.L.Wendl.A. hookeri Sond.A. humilis Sond.A. imbricata Willd.A. insignis PillansA. involucrata Eckl. & Zeyh.A. joubertiana Schltdl.A. juniperifolia Bartl.A. kougaensis PillansA. krakadouwensis DümmerA. lanceolata Engl.A. lancifolia Eckl. & Zeyh.A. latipetala Sond.A. leptospermoides Sond.A. linifolia Licht. ex Bartl. & H.L.Wendl.A. longicornu PillansA. marifolia Eckl. & Zeyh.A. marlothii DümmerA. martiana Sond.A. microcalyx DümmerA. microcarpa PillansA. minuta Schltdl.A. mirabilis PillansA. mucronulata Sond. – BuchuA. muirii E.PhillipsA. mundtii Cham. & Schltdl.A. namaquensis PillansA. odoratissima PillansA. orbicularis Bartl. & H.L.Wendl.A. ovalifolia PillansA. ovata Pillans – False buchuA. pallens PillansA. pattisonae DümmerA. peglerae DümmerA. pentachotoma E.Mey. ex Sond.A. perdita Hutch.A. phillipsii DümmerA. pilifera Schltdl.A. planifolia Sond.A. propinqua Sond.A. puberula Fourc.A. pubigera Sond.A. pulchella LinkA. pungens PillansA. purpurea PillansA. recurvifolia Sond.A. rehmanniana DümmerA. riversdalensis DümmerA. robusta Eckl. & Zeyh. A. roodebergensis ComptonA. rosmarinifolia I.WilliamsA. rubricaulis DümmerA. rudolphii I.WilliamsA. sabulosa Sond.A. salina Eckl. & Zeyh.A. scaberula DümmerA. sedifolia Schltdl.A. serpyllacea Licht. ex Schult.A. serratifolia SpreethA. sladeniana GloverA. spinescens DümmerA. spinosa Sond.A. squamosa Bartl. & H.L.Wendl.A. stenopetala Steud.A. stenosepala PillansA. stilbeoides DümmerA. stipitata PillansA. stokoei PillansA. subteretifolia PillansA. tabularis Sond.A. thymifolia Schltdl.A. trichocarpa HolmesA. tulbaghensis DümmerA. umbonata PillansA. unicarpellata PillansA. venusta PillansA. villosa Willd. A. virgata Bartl. & H.L.Wendl.A. zwartbergensis Pillans