Rauvolfia micrantha, the small-flowered snakeroot,[1] is a plant that is indigenous to southwestern India, southern Thailand, and Vietnam. It has a woody, shrub-like appearance and attractive flowers.
| Rauvolfia micrantha | |
|---|---|
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Gentianales |
| Family: | Apocynaceae |
| Genus: | Rauvolfia |
| Species: | R. micrantha
|
| Binomial name | |
| Rauvolfia micrantha | |
Distribution and habitat
editThe general habitat of plants in the genus Rauvolfia is semi-evergreen and evergreen forest distributed along tropical areas of Asia, Africa, and America. The plant is endemic to the evergreen forest of the Tinnevelly and Travancore hills in the Indian Western Ghats (states of Kerala and Tamil Nadu.[2] It flowers and fruits between March and October.[3]
Conservation
editRauvolfia micrantha is a critically endangered plant. The species has scanty distribution in the wild due to habitat degradation, fragmentation of population and narrow environmental niche.[3] Efforts toward its conservation involve cryopreservation of seeds and in-vitro methods.[4] Organogenesisis the standardized protocol for regeneration of R. micrantha in culture. Nodes of the plant are used as explants.[5] Cryopreservation of the seeds has proven to be slightly difficult. The seeds of R. micrantha are of intermediate type and hence require strict conditions during this process.[5]
Morphology, flowers and fruits
editThe plant is a perennial woody shrub that grows at elevations up to about 600 m (2,000 ft). Branches are slender and glabrous (having no trichomes or "hair"). The leaves are approximately 8–13 cm (3–5 in) x 2–5 cm (0.8–2 in), elliptic, membranous, abruptly acuminate at both ends; petiole 1 cm long.[6][7] Flowers are arranged in axillary long-peduncled congested cymes; sepals are 1.5 mm (0.059 in) long, triangular, acute and basely connate. The corolla is colored white with reddish color at throat, and is about 8 mm (0.31 in) long, glabrous, with acute ovate lobes. Capsule is 7 mm (0.28 in) x 5 mm (0.20 in), ovoid acute, and glabrous.[6] Fruits are obliquely ovate and pointed.
Rauvolfia micrantha is related to the snakeroot plant (Rauvolfia serpentina) which is used as a traditional herbal medicine. However, isoenzyme analysis reveals that it is more closely related to Rauvolfia tetraphylla L.[8]
Reproduction
editFlowering reaches its peak in the month of May and anthesis occurs between 5:00 am and 8:30 am with a peak at 7:00 am. Dehiscence occurs between 6:00 am and 10:30 am on the day of the anthesis. The stigmas are receptive the day before anthesis, however, become increasingly receptive on the day of anthesis.[3] The major insect pollinators included Apis florea (honeybee), Oecophylla smargadina (red ant), Tetragonula iridipennis (pollen bee) and butterflies such as Pachliopta aristolochaea, Pachliopta hector, Delias eucharis and Euploea core.[3]
Alkaloids
editHairy root induction of the plant is achieved in culture by using infection with Agrobacterium rhizogenes strains.[9]
- Hairy root: ajmaline, ajmalacine, reserpine, reserpiline,[10] sarpagine, and serpentine[11]
- Root bark: aunamine and neosarpagine
Other nutrients and chemicals in the plant include phenolics, flavonoids, vitamins and carotenoids. The extracts also had antioxidant properties in vitro.[12]
Uses
editThe plant is used as a substitute for R. serpentina in Ayurvedic practices in Kerala, India for nervous disorders such as insomnia and insanity.[citation needed]
References
edit- ^ "Taxonomic Information for Rauvolfia Micrantha- Biological Classifications & Names- Encyclopedia of Life". Encyclopedia of Life. Retrieved 3 May 2014.
- ^ Patil, V.M.; Jayanthi (1997). "Micropropagation of Two Species of Rauvolfia (Apocynaceae)". Current Science. 72 (12): 961–965.
- ^ a b c d Kulloli, S.K.; Sreekala (2009). "Pollination Ecology of Rauvolfia Micrantha Hook.F. (Apocynaceae): A Critically Endangered Medicinal Plant from the Southern Western Ghats". Phytomorphology. 59 (3 & 4): 96–101.
- ^ Sudha, G.G.; S. Seeni (1996). "In Vitro Propagation of Rauwolfia Micrantha, a Rare Medicinal Plant". Plant Cell, Tissue and Organ Culture. 44 (3): 243–248. doi:10.1007/bf00048530. S2CID 6951195.
- ^ a b Krishnan, Peringattulli Narayanan; S.W. Decruse; R.K. Radha (2011). "Conservation of Medicinal Plants of Western Ghats, India and Its Sustainable Utilization through in Vitro Technology". In Vitro Cellular & Developmental Biology - Plant. 41 (1): 110–122. doi:10.1007/s11627-011-9344-9. S2CID 23645571.
- ^ a b "Rauvolfia Micrantha". India Biodiversity Portal. Retrieved 3 May 2014.
- ^ Youngken, Heber W. (1954). "Malabar Rauwolfia, Rauwolfia Micrantha Hook.F.". Journal of the American Pharmaceutical Association. 43 (3): 141–143. doi:10.1002/jps.3030430305. PMID 13142931.
- ^ Nanthini, A. U.; M. Johnson; F.M. Franco; T.R. Malar (2011). "Assessing the Genetic Relationship Between Three Selected Species of Rauvolfia Using Isoenzyme Profiles and Morphological Characters". Journal of Phytology. 3 (9): 48–54.
- ^ Sudha, C. G.; Obul Reddy, B.; Ravishankar, G. A.; Seeni, S. (2003). "Production of Ajmalicine and Ajmaline in Hairy Root Cultures of Rauvolfia Micrantha Hook F., a Rare and Endemic Medicinal Plant". Biotechnology Letters. 25 (8): 631–636. doi:10.1023/A:1023012114628. PMID 12882157. S2CID 11855109.
- ^ Pillay, P.P.; D.S. Rao; S.B. Rao (1960). "Chemical Investigation of Rauvolfia Micrantha Hook F.". Journal of Scientific and Industrial Research. 19B: 135–137.
- ^ Sudha, C.G.; S. Seeni (2006). "Spontaneous Somatic Embryogenesis on in Vitro Root Segment Cultures of Rauvolfia Micrantha Hook, F.- A Rare Medicinal Plant". In Vitro Cellular & Developmental Biology - Plant. 42 (2): 119–123. doi:10.1079/ivp2005738. S2CID 13172437.
- ^ Nair, Vadakkemuriyil; Rajaram Panneerselvam; Ragupathi Gopi (2012). "Studies on Methanolic Extract of Rauvolfia Species from Southern Western Ghats of India- In Vitro Antioxidant Properties, Characterization of Nutrients and Phytochemicals". Industrial Crops and Products. 39: 17–25. doi:10.1016/j.indcrop.2012.02.006.