June 2016 The Journal of Japanese Botany Vol. 91 No. 3 179 J. Jpn. Bot. 91: 179–183 (2016) Aabid Hussain Mira, Krishna Upadhayab,* and Clarence G. Khonglaha: A Note on Mitrastemon yamamotoi (Mitrastemonaceae): a Root Parasite of Rare Occurrence in North East India a Department of Environmental Studies, North-Eastern Hill University, Shillong-793022, INDIA; Department of Basic Sciences and Social Sciences, North-Eastern Hill University, Shillong-793022, INDIA *Corresponding author: upkri@yahoo.com b Summary: Mitrastemon yamamotoi Makino (Mitrastemonaceae) is the only species of the genus found in the state of Meghalaya, North East India. The present study is a recollection of the species for the second time after a gap of about 45 years. In addition to its detailed taxonomic description, habitat characterization, threats operating on the species and related conservation implications are also discussed. The genus Mitrastemon is represented by two species, i.e., Mitrastemon matudae Yamam. and M. yamamotoi Makino. The former is found in Central America, and the latter in tropical and subtropical Asia. The genus belongs to the family Mitrastemonaceae, grows as herbs and lives as parasites on roots of some trees. In India, the genus is represented by only one species i.e., Mitrastemon yamamotoi, and it is found only in Khasi Hills of Meghalaya (Meijer and Veldkamp 1993). Mitrastemon yamamotoi is a unique root parasite and is considered a good example of transpaciic distribution. It was irst reported by Makino in 1909 from Japan as Mitrastemma yamamotoi (Makino 1909), and was later corrected as Mitrastemon yamamotoi (Makino 1911). In India, this species was irst collected in 1969 by Rao and Balakrishnan from Mawsmai forest in East Khasi Hills of Meghalaya (Rao and Balakrishnan 1972). Since then the species has not been collected from the state (Nayar and Sastry 1990). The species was listed as ‘Rare’ by Walter and Gillett (1998) and is classiied as ‘Endangered’ in the Red Data Book of Indian Plants (Nayar and Sastry 1990). Even in Japan the species is considered ‘Rare’ (Makino 1911). In the present study, a detailed distribution, plant description, habitat characterization, threat operating on the species and conservation measures that need to be adopted are discussed, so as to prevent the species from extinction in India. During a recent floristic exploration carried out in Cherrapunjee and adjoining areas in East Khasi Hills district of Meghalaya, we came across this interesting species. After a critical examination, comparison with the original description and available literature (Makino 1909, 1911, 1928, Hayata 1913, Matuda 1947, Rao and Balakrishnan 1972, Huang and Gilbert 2003) as well as comparison with the herbarium specimens of Botanical Survey of India, Eastern Circle, Shillong, its identity was confirmed as Mitrastemon yamamotoi. The vegetation of the area, where the species was collected falls under subtropical broadleaved wet-hill forests (Champion and Seth 1968). The dominant canopy trees of the forests include Castanopsis tribuloides (Sm.) DC., Castanopsis kurzii (Hance) Biswas, Echinocarpus murex Benth., Elaeocarpus spp., Lithocarpus dealbatus Rehder, L. elegans (Blume) Hatus. ex Soepadmo, Quercus glauca Thunb., Syzygium spp. and Schima khasiana Dyer. Whereas, the sub-canopy layer is dominated by Casearia glomerata Roxb., Coffea khasiana Hook. f., Eurya spp., Macropanax dispermus (Blume) Kuntze, Microtropis discolor (Wall.) Meisn., 180 植物研究雑誌 第 91 巻 第3号 2016 年 6 月 Fig. 1. Mitrastemon yamamotoi during different growth stages. A. Budding stage. B. Blooming stage. C. Mature individuals showing intimate attachment with roots. D. Dehiscent stage. E. Dead individuals. F. Remaining marks on plant roots. All taken from Mawmluh, Cherapunjee, Megalaya, India. A. 3 Dec. 2014. B, C. 5 Feb. 2015. D. 10 Mar. 2015. E. 26 Mar. 2015. F. 7 Apr. 2015. June 2016 The Journal of Japanese Botany Vol. 91 No. 3 181 Table 1. Site characteristic of forest patches with Mitrastemon yamamotoi in Khasi Hills, Megalaya, India Site Law Spurba, Mawmluh Law Saiawmih, Mawsmai Law Arliang, Laitryngew Law Pjah, Laitryngew Area (ha) Latitude (N) Longitude (E) Elevation (m) Disturbances 948 86 4.05 3.02 25°14.903ʹ 25°14.354ʹ 25°19.921ʹ 25°19.748ʹ 91°41.968ʹ 91°43.841ʹ 91°44.159ʹ 91°44.069ʹ Psychotria spp., Schefflera hypoleuca (Kurz) Harms, Schefflera venulosa (Wight & Arn.) Harms, Symplocos spicata Roxb., Sarcococca pruniformis Lindl. and Vernonia volkameriifolia DC. Taxonomic description Mitrastemon yamamotoi Makino in Bot. Mag. (Tokyo) 23: (326), t. (1909), ut ‘Mitrastemma’, & in Bot. Mag. (Tokyo) 25: 255, t. 7 (1911); Rao & Balakrishnan in Indian Forester 98(4): 234 (1972). Cylindrical body, 3–7 cm tall, stem erect with tuberous base. All parts off-white when young and dark brown when dry. Volva 1.5–2.5 × 0.5–2 cm. Scales 12, decussately opposite, imbricate, in three tiers of four each, sub-erect ascending, ovate, ovate-oblong, or lanceolate, 1–2.7 × 0.5–2 cm. Perianth fleshy white when young and brown when old, cupular, 0.5 × 1–1.9 cm, mouth entire or undulate. Staminal tubule, 14–20 mm long, anther many celled, honey-combed in a 2–6 mm broad ring. Ovary globose to ellipsoid, superior, sessile ca. 12 × 9 mm, unilocular; placentae parietal with sinuately intruding lamellae masking the single locule. Ovules many on slender stalks, anatropous. Style stumpy, conical, stout, 3–4 mm long. Stigma subglobose, 4–5 mm long, 5–7 mm thick. Fruits subglobose-ovoid, 20–25 mm in diameter, dark brown, enclosed in dark brown scales. Seeds many, 3 mm long, brown (Figs. 1, 2). Flowering and fruiting period: The plant is seen only during the winter season and it completes the whole life cycle from November to April. Specimens examined: INDIA. MEGHALAYA: East Khasi Hills: Laitryngew near Cherrapunjee, 5 February 1115 1074 1603 1582 low moderate high high Population size large small small small 2015, A. H. Mir 87863 (ASSAM); Mawmluh, 5 February 2015, A. H. Mir 87864 (ASSAM). Khasi and Jaintia Hills: 1966, A. S. Rao 37958 (ASSAM); 1971, A. S. Rao 38222– 38224, 38285 (ASSAM); 1969, Balakrishnan 34188 (ASSAM). The plant is reported from India (Meghalaya), Thailand, Cambodia, Vietnam China (Fujian, Guangdong, Guangxi, Taiwan, Yunnan), Japan (Shikoku, Kyushu, Ryukyu Islands), Sumatra, Borneo and New Guinea. In Meghalaya, the species was thought to be restricted only to the Mawsmai area (Rao and Balakrishnan 1972), but during the current study, in addition to the previous site, it could be collected from three fragmented forest patches located in Mawmluh and Laitryngew (Table 1). Mitrastemon yamamotoi is a root parasite on many tree species and grows in thick, moist virgin forests (Rao and Balakrishnan 1972). The species grows so closely with the host that it seems to be a part of the host plant. The species grows mainly in moist and shady areas of the forests. Earlier it was reported to grow mainly on roots of Engelhardia spicata Blume, Castanopsis tribuloides, Vernonia volkameriifolia and Elaeocarpus lancifolius Roxb. (Rao and Balakrishnan 1972). But during our survey, in addition to above species it was found to grow on roots of Lithocarpus elegans, Psychotria adenophylla Wall., Calophyllum polyanthum Choisy and Elaeocarpus floribundus Blume as well. The majority of the individuals were found to grow on the roots of Lithocarpus elegans and Psychotria adenophylla. The habitat of the species is characterized by low light intensity (6–30 µmol m−2 s−1), low air temperature (10–19 °C), high relative humidity (80–97%) and high rainfall (11,000 mm per year). However, there 182 植物研究雑誌 第 91 巻 第3号 2016 年 6 月 Fig. 2. Mitrastemon yamamotoi. A. Longitudinal section of a plant. B. Volva. C. Transverse section of the ovary. D. Scales. E. Bracts. All from Mawmluh, Cherapunjee, Megalaya, India. is low or no rainfall during the winter months (December–February). Except rainfall, these environmental parameters are more or less similar to those of other parts of the world where this species is growing (Matuda 1947). It has also been observed that the plant exudates a honey like fluid in order to attract birds and insects, which aid the plant in pollination (Fig. 1D). The population size of the species in the studied sites was very small and is in the danger of extinction. The major threats operating in the area of its occurrence are fragmentation and habitat destruction due to shifting cultivation, June 2016 The Journal of Japanese Botany Vol. 91 No. 3 deforestation for small timber and fuel wood collection, medicinal plant collection for commercial purposes, forest fires and mining of coal, limestones and sand (Upadhaya et al. 2013). The ever increasing forest fragmentation is changing the microclimatic conditions of the forests, hence making the environment unfavorable for the growth of this species. Moreover, because of its parasitic nature, cultivation of this species seems to be very difficult (Nayar and Sastry 1990). So far no conservation measures have been taken for the species in India. In order to conserve the species from extinction from the country, these forest patches in which the species occurs needs strict protection. In addition, regular monitoring of the population is needed. The authors are thankful to Ministry of Environment, Forest and Climate Change (MoEF & CC) for the financial support (No.14/25/2011-ERS/RE) and Botanical Survey of India (Eastern Circle, Shillong) for the help. The cooperation from the Headmen and the local people during the study is also acknowledged. References Champion H. G. and Seth S. K. 1968. A Revised Survey 183 of the Forest Types of India. Manager of Publications, Government of India, Delhi. Hayata B. 1913. On the systematic position of Mitrastemon. Icon. Pl. Formos. 3: 199–213. Huang S. M. and Gilbert M. G. 2003. Rafflesiaceae. In: Wu Z. Y., Raven P. H. and Hong D. Y. (eds.), Flora of China 5: 270–271. Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis. Makino T. 1909. On Mitrastemma yamamotoi. Makino, gen. et sp. nov. Bot. Mag. (Tokyo) 23: (325)–(327). Makino T. 1911. Observations on the lora of Japan. Bot. Mag. (Tokyo) 25: 251–257. Makino T. 1928. A contribution to the knowledge of the lora of Japan. J. Jap. Bot. 5: 18. Matuda E. 1947. On the genus Mitrastemon. Bull. Torrey Bot. Club. 74: 133–141. Meijer W. and Veldkamp J. F. 1993. A revision of Mitrastema (Raflesiaceae). Blumea 38: 221–229. Nayar M. P. and Sastry A. R. K. 1990. Red Data Book of Indian Plants.Volume III. Botanical Survey of India, Calcutta. Rao A. and Balakrishnan N. P. 1972. Mitrastemon yamanotoi (Makino) Makino (Rafflesiaceae) – A unique root parasite new to the Indian flora. Indian Forester 98(4): 234–235. Upadhaya K., Thapa N., Lakadong J. N., Barik S. K. and Sarma K. 2013. Priority areas for conservation in North East India: A case study in Meghalaya based on plant species diversity and endemism. Int. J. Ecol. Environ. Sci. 39(2): 125–136. Walter K. S. and Gillett H. J. 1998. IUCN Red List of Threatened Plants. Complied by the World Conservation Union, Gland, Switzerland and Cambridge. A. H. Mira，K. Upadhayab，C. G. Khonglaha：北東イン ド稀産の寄生植物─ヤッコソウ（ヤッコソウ科） ヤッコソウ Mitrastemon yamamotoi Makino（ヤッコ ソウ科）はインドでは北東部のメガラヤ州 Khasi Hills でのみ知られていたが，最近になって同所で 45 年ぶり に採集された．これが二度目の報告となる．本稿では， 新しく得られた材料にもとづいて，ヤッコソウの詳しい 記載，生育地の特性，種の現況と保全への方策を示した． （a インド・North-Eastern Hill University， b Department of Environmental Studies， インド・North-Eastern Hill University， Department of Basic Sciences and Social Sciences）