K.L. Chaudhary1* & S.K. Singh2
1Lady Keane College, Shillong, Meghalaya, India
2Botanical Survey of India, North Eastern Circle, Shillong, Meghalaya, India
*Corresponding author: K.L. Chaudhary; email: firstname.lastname@example.org
Adiantum flabellulatum L. – a rare species of fern has recently been collected from Umran in Ri-Bhoi district of Meghalaya. A brief description and photographs are provided to facilitate its easier identification.
Keywords Adiantum flabellulatum, Pteridophyte, Ri-Bhoi district, Meghalaya
The genus Adiantum L. is evidently an old and morphologically isolated genus belong to family Adiantaceae. The genus is pantropical in distribution with extensions northward to Newfoundland, Alaska, and NE Asia, and southward to southern South America, southern Africa, and New Zealand. Many species grow in primary or secondary forest, others on cliffs or on rocky slopes (Kramer & Green, 1990). About 225 species known under the genus from across the world (Huiet et al., 2015) and about 31 taxa are recorded from India (see Fraser- Jenkins 2008), however some records are dubious and need a detailed study.
Adiantum flabellulatum L. [distributed globally in India, Sri Lanka, Japan, Myanmar, China, Taiwan and S.E. Asia; Fraser-Jenkins et al., 2015] is a rare species in India, reported from Assam, Meghalaya and Manipur in NE India only (Chandra et al., 2008). Regional herbarium study (ASSAM) reveals that only 10 specimens belong to this species are from Garampani, Garbhanga Reseve Forests, Haflong and Kopili (all in State of Assam). Though, in Meghalaya, this species had earlier been reported from Umroi in Ri-Bhoi District (Baishya & Rao, 1982) but no herbarium specimens available. The present collection is from ‘Breezedale forest’, a rather well preserved private forest in Umran Niangbyrnai Village, Umran, Ri-Bhoi District. Four populations, with a total of less than a hundred plants were located here. Considering its rarity, we are attempting to provide updated information about the species based on our recent collections.
Adiantum flabellulatum L., Sp. Pl. 2: 1095. 1753. Adiantum fuscum Retz., Obs. Bot. 2: 28, t. 5. 1781. Adiantum amoenum Wall. ex Hook. & Grev., Icon. Fil. 1(6): t. 103. 1828. Adiantum bonii Christ, J. de Bot. 8: 150. 1894.
A terrestrial, erect, rhizomatous fern, with stipes up to 40 cm high. Rhizome short, branched, semi-erect, c. 0.5 cm across, scaly; scales dark-brown, linear c. 0.5 cm long, 0.8 mm broad. Stipe black, up to 40 cm long, distinctly grooved with short stiff brown hairs inside, asymmetrically branched, compound-fronded with rather rounded and toothed segments, base covered with brown scales, glabrous on upper side. Lamina flabellate, bipartite, pedately divided, tripinnate or occasionally quadripinnate, ovate-cordate in shape, c. 20 – 25 × 18 cm. Pinnae alternate, sometimes solitary on the ultimate branches; basal pinnae stalked and upper ones almost sessile or subsessile; pinnules glabrous, subcoriaceous, obliquely cuneate or semiorbicular-cuneate, lower margin almost straight or slightly concave, base straight or concave, smooth, outer margin convex, 2 – 4-lobed, the lobes subserrate, apex rounded; rachis and branches covered by a felt of hairs. Sori transversely oblong, crowded all over the outer margin, c. 2 mm broad and 5 mm long; false indusia dark brown, sub-orbicular, persistent.
Fertile: May – June.
Distribution: INDIA [Assam, Meghalaya, Nagaland, Manipur, Tripura], CHINA, TAIWAN, JAPAN, MYANMAR, SRI LANKA AND S.E. ASIA (Fraser-Jenkins et al., 2015).
Specimen examined: Meghalaya, Ri-Bhoi District, Umran Niangbyrnai Village, 25°46’17.7″ N, 91°52’22.10″ E, alt.705 m asl, 29.12.2015. K L Chaudhary 0001 (Herbarium of Lady Keane College).The specimen is found growing on soil in shaded areas.
Other specimens examined: Assam, Garampani, 1956. G. Panigrahi, 5406 (ASSAM); Assam, Garampani, 1956. G. Panigrahi, 5407 (ASSAM); Assam, Garampani, 1956. G. Panigrahi 58110 (ASSAM); Assam, Garbhanga Reserve Forest, 1957. G. Panigrahi 5408 (ASSAM); Assam, Garbhanga Reserve Forest, 1957. G. Panigrahi 5409 (ASSAM); Assam, Garbhanga Reserve Forest, 1957. G. Panigrahi 28594 (ASSAM); Assam, Garampani, G. Panigrahi 5410 (ASSAM); Assam, Garampani, 1974, S.R. Ghosh, 5411 (ASSAM); Assam, North Cachar Hills, Haflong, 1976, N.C. Deori, 82670 (ASSAM); Assam, North Cachar Hills, Kopili, 2007, R.S. Baruah, 68542 (ASSAM);
The authors are thankful to Mr. C.R. Fraser-Jenkins, Kathmandu, Nepal for confirming the identity. KLC would like to thank the Meghalaya Biodiversity Board for the Financial Assistance; the Principal, Lady Keane College, Shillong & Head, Dept. Of Botany, Lady Keane College for the necessary permission, facilites and encouragement. SKS is thankful to Director Botanical Survey of India, Kolkata and Scientist F and Head, BSI, ERC, Shillong for necessary facilities and encouragements.
Baishya, A.K. & Rao, R.R. 1982. Fern and Fern-allies of Meghalaya State, India. Scientific Publishers, Jodhpur, India.
Chandra, S., Fraser-Jenkins, C.R., Kumari, A. and Srivastava, A. 2008. A Summary of the Status of Threatened Pteridophytes of India. Taiwania, 53(2): 170–209.
Huiet, L., Lenz, M., Nelson, J.K., Pryer, K.M. & Smith, A.R. 2015. Adiantum shastense, a new species of maidenhair fern from California. Phytokeys 53: 73–81.
Fraser-Jenkins, C.R. 2008. Taxonomic revision of three hundred Indian subcontinental pteridophytes with a revised census-list – a new picture of fern-taxonomy and nomenclature in the Indian subcontinent, Bishen Singh Mahendra Pal Singh, Dehradun, India.
Fraser-Jenkins, C.R., Kandel, D.R. & Pariyar, S. 2015. Ferns and Fern-allies of Nepal, Volume 1, National Herbarium and Plant Laboratories Department of Plant Resources, Thapathali, Kathmandu, Nepal.
Kramer, K.U. & Green, P.S. 1990. The Families and Genera of Vascular Plants I Pteridophytes and Gymnosperms. Springer-Verlag Berlin Heidelberg.