Croton anisatum (aka Croton anisatus) is a protected rare plant native to the upper slopes of the Ankaratra Massif in central Madagascar. Anisatum is the source of a fragrant, volatile oil that resembles the scent of true anise (Pimpinella anisum). Essential oil of Croton anisatum should not be confused with incense oils produced from Japanese Star Anise (Illicium anisatum), which are toxic if taken internally.
Croton anisatum is a hardwood shrub that can reach tree height, up to eight meters. Leaves are elliptical to narrowly elliptical and are held on short petioles. Flowers are pale green to white, with pale green bracts and are terminal, at the end of branches. Both male and female flowers are borne on the same plant. Fruits are pale green and covered with short white hairs. All parts of the plant have the aroma of anise seeds.
Croton anisatum is native to Madagascar and was originally described in 1861 by Henri Baillon, a French botanist who worked extensively with the Euphorbia family, which includes C. anisatum. An earlier botanist, Joseph Hubert, cultivated anisatum at his garden on Saint-Beloit (Reunion Island, east of Madagascar), where it flowered, but did not set seed or bear fruit. Specimens of this shrub were first collected in the wild by French botanist Paul Lepervanche.
Collectors have found Croton anisatum at the Manjakatompo Forestry Station, a privately funded nature preserve in Antananarivo Province in central Madagascar. Anisatum's habitat ranges in elevations from 1,550 to 2,602 meters (5,085 to 8,536 feet). The site is a "sky island," a patch of 6.5 square kilometers (2.5 square miles) of native forest, a remnant of a larger contiguous montane forest that existed during the cooler climate of a glacial epoch. The current vegetation is "ericoid thicket," a high altitude, subhumid ecosystem dominated by the Ericaceae family, which includes heathers and blueberries. Anisatus is also found at a similar site in Taomasina Province in eastern Madagascar.
Of the 125 species that represent the Croton genus in Madagascar, about 40 are used locally for medicinal purposes. Leafy branches of Croton anisatum are infused and taken as tea to heal colic and dysentery. Expam Limited, a USDA-certified organic homeopharmaceutical producer located in Antananarivo, Madagascar, processes essential oils from the bark of Croton anisatum. The oils are marketed for fragrance and as a "calming" additive to massage oils.
Croton anisatum is harvested from the wild for commercial production of aromatic oils. As a natural resource, Croton anisatum is monitored among 6,000 protected medicinal plants under Madagascar's biodiversity statue. Other protected Madagascar Crotons are C. arenicola, C. bojerianum, C. geayi, C. greveanus, C. louvelii and C. stanneum.