PUBLISHED BY THE OIKOS EDITORIAL OFFICE NORDIC JOURNAL OF BOTANY Rotala sahyadrica sp. nov. (Lythraceae) from Western Ghats, India S. P. Gaikwad, M. M. Sardesai and S. R. Yadav DOI: 10.1111/j.1756-1051.2013.00322.x, Volume 32, Issue 5, Pages 575–577 If you wish to order reprints of this article, please follow the instructions here EMAIL ALERTS Receive free email alerts and stay up-to-date on what is published in Nordic Journal of Botany – click here CONNECT WITH US Follow Nordic Journal of Botany on Twitter and Facebook Submit your next paper to NJBOT online at http://mc.manuscriptcentral.com/njbot Subscribe to Nordic Journal of Botany and stay up-to-date with a wide variety of new findings of relevance to the botanical biodiversity on Earth. All Nordic Journal of Botany volumes since the journal started in 1981 are available as fulltext for subscribers online at Wiley Online Library – click here To take out a personal subscription, please click here More information about Nordic Journal of Botany at http://nordicjbotany.org Nordic Journal of Botany 32: 575–577, 2014 doi: 10.1111/j.1756-1051.2013.00322.x, © 2013 he Authors. Nordic Journal of Botany © 2013 Nordic Society Oikos Subject Editor: Torbjörn Tyler. Accepted 24 July 2013 Rotala sahyadrica sp. nov. (Lythraceae) from Western Ghats, India S. P. Gaikwad, M. M. Sardesai and S. R. Yadav S. P. Gaikwad, Dept of Botany, Walchand College of Arts and Science, IN-413 006 Solapur, India. – M. M. Sardesai (sardesaimm@gmail.com), Dept of Botany, Dr Babasaheb Ambedkar Marathwada Univ., IN-431 004 Aurangabad, India. – S. R. Yadav, Dept of Botany, Shivaji Univ., Vidyanagar, IN-416 004 Kolhapur, India. A new aquatic species, Rotala sahyadrica S. P. Gaikwad, Sardesai et S. R. Yadav sp. nov. collected from a fresh water lake on a high altitude lateritic plateau ecosystem of the Western Ghats, India is described and illustrated here. It is similar to R. tenella (Guill. & Perr.) Hiern but differs in having cleistogamous and chasmogamous flowers, nectary glands on calyx tube and 8–12 multi-cellular black trichomes in the axils of bracteoles. he genus Rotala L. was earlier represented by ca 44 species, distributed mostly in tropical and subtropical regions of the world (Cook 1979, 1996, Mabberley 2008). After Cook’s revision in 1979, 11 species have been added to the genus by various workers (Lu 1979, Joseph and Sivarajan 1988, 1989, Bamps 1989, Beesley 1990, Mathew and Lakshminarasimhan 1990, Pradeep et al. 1990, Yadav et al. 2010, Prasad et al. 2012, Sunil et al. 2013, Prasad and Raveendran 2013). However, Almeida (1998) reduced one species to the rank of variety. Hence, the total number of species in the genus is now 54. In India the genus is represented by 25 species, of which 21 are found in Peninsular India (Prasad and Raveendran 2013). As a part of field survey of rare, endangered and endemic flowering plants of northern Western Ghats of India, the authors collected some interesting specimens of a species of Rotala from a fresh water lake on Kas plateau in Satara district of Maharashtra state. Critical examination and perusal of the literature revealed that it was quite different from any of the known taxa of the genus Rotala. herefore, it is described and illustrated here as a new species. Rotala sahyadrica S. P. Gaikwad, Sardesai et S. R. Yadav sp. nov. (Fig. 1) Type: India, Maharashtra, Satara, Kas plateau, 17°44′07.58″N and 73°48′46.65″E, 23 km west to the Satara city, at 900 m a.s.l., 26 Sep 2003, S. P. Gaikwad 399 (holotype: CAL, isotypes: BAMU, BSI, SUK). Etymology he specific epithet ‘sahyadrica’ is derived from the geographical name, Sahyadri Mountains (northern Western Ghats) which includes the type locality. Description An aquatic annual herb; stem up to 30 cm long, obtusely angular below, acutely quadrangular above, erect, rarely branched. Leaves simple, opposite, decussate, sessile, dimorphic, membranous; submerged leaves linear-oblong, rounded at both the ends, 4.0–6.5 ⫻ 0.6–1.0 cm, reddish or greenish, entire, with lateral nerves in 3–5 pairs, distinct; aerial leaves obovate-orbicular, cordate at base, rounded at apex, modified into bracts, 0.5–1.5 ⫻ 0.3–1.0 cm, reddish, entire. Flowers axillary, solitary, sessile, those on submerged shoots cleistogamous, but chasmogamous on emergent shoots. Bracts leafy. Bracteoles 2, linear-subulate, 0.7–0.9 mm long, much shorter than the calyx tube, persistent, with 8–12 multi-cellular, unbranched, 0.2–0.6 mm long, black hairs at the axils. Floral tube subcylindric to urceolate, pink at anthesis in chasmogamous flowers, 2.5–3.3 mm long, enlarging during fruiting; lobes 4, triangular, 0.2–0.3 mm long; calyx appendages absent. Petals 4, obovate, 0.9–1.1 ⫻ 0.8–0.9 mm, obtuse, clawed at base, rosy–white, opposite to the calyx lobes, slightly exerted in chasmogamous flowers. Stamens 4, inserted below the middle of calyx tube, included; filaments narrow towards apex, white, 1.0–1.4 mm long; anthers borne just below the level of the base of petals, twice as broad as long. Nectary glands form a continuous rim on the calyx tube from where filaments arise. Ovary ellipsoid, 1.1–1.3 ⫻ 0.9–1.0 mm, yellowish; style simple, short, persistent in fruit; stigma capitate, minutely pilose, included in calyx tube. Capsule ellipsoid, 3.00–3.50 ⫻ 2.00–2.25 mm, slightly protruding from the calyx tube, 4-valved; valves conduplicate, septicidally dehiscent. Seeds ovoid-ellipsoid, 0.15–0.19 ⫻ 0.20– 0.15 mm, in 2–3 rows in each locule, brownish. Flowering and fruiting in July–February. 575 Figure 1. Rotala sahyadrica sp. nov. (a) habit, (b) node showing flowers, (c) multi-cellular black hairs, (d) bracteoles, (e) submerged flower, (f ) aerial flower, (g) flower cut open, (h) fruit, (i) seeds. From S. P. Gaikwad 399, drawn by S. P. Gaikwad. Ecology Rotala sahyadrica is a true aquatic herb which grows in a fresh water lake on the lateritic plateau at about 900 m altitude in Sahyadri ranges of Western Ghats, India. During the rainy season (July–October) it remains submerged and 576 produces only cleistogamous flowers. However, in the winter (November–February) as the water level recedes, the species starts to produce chasmogamic flowers on the emergent aerial branches. here are no structural differences in chasmogamic and cleistogamic flowers except for the smaller Table 1. Comparison between Rotala sahyadrica sp. nov. and R. tenella (Guill. & Perr.) Hiern. Character R. sahyadrica R. tenella Distribution Habit Cleistogamous flowers Flowers Nectary glands India Submerged aquatic Present Sessile Present in the form of a continuous rim on the calyx tube from where filaments arise Present, 8–12 multi-cellular black hairs Not accrescent Africa Amphibious Absent Pedicellate; pedicel in fruit up to 2 mm long Absent Hairs in axils of bracteoles Calyx after anthesis size of the latter. he common associates of the species are Limnophila sessiliflora (Vahl.) Blume, Ludwigia perennis L., Myriophyllum oliganthum (Wight. & Arn.) F. von Muell, Nymphoides hydrophylla (Lour.) Kuntze and Persicaria glabra (Willd.) Gomez. Similar species Rotala sahyadrica is closely allied to R. tenella (Guill. & Perr.) Hiern, but differs from the latter species by the characters given in Table 1. Acknowledgements – he authors are thankful to Dr P. Lakshminarasimhan for comment on identity of the species, first two authors thank to the Dept of Science and Technology (DST), New Delhi for providing financial assistance under SERC FAST TRACK proposal for young scientists 2000 scheme. References Almeida, M. R. 1998. Flora of Maharashtra. – Blatter Herbarium, St Xavier’s College, Mumbai 2: 290. Bamps, P. 1989. Rotala letouzeyana, Lythraceae nouvelle du Zaire (Rotala letouzeyana, a new Lythraceae from Zaire). – Bull. Mus. Natl Hist. Nat. B. Adansonia 11: 389–390. Beesley, P. L. 1990. Rotala. Lythraceae in George, A. S. (ed.), Flora of Australia. – Austr. Govt Publ. Serv. Canberra 18: 92–97, 323. Absent Distinctly accrescent Cook, C. D. K. 1979. A revision of the genus Rotala (Lythraceae). – Boissiera 29: 1–156. Cook, C. D. K. 1996. Aquatic and wetland plants of India. – Oxford Univ. Press, pp. 1–385. IUCN 2001. IUCN red list categories and criteria, ver. 3.1. – IUCN Species Survival Commission. Joseph, K. T. and Sivarajan, V. V. 1988. Rotala cookii: a new species of Lythraceae from India showing Hippuris syndrome. – Plant Syst. Evol. 159: 141–144. Joseph, K. T. and Sivarajan, V. V. 1989. Rotala Linn. (Lythraceae) in Peninsular India. – Proc. Ind. Acad. Sci. Plant Sci. 99: 179–197. Lu, F. Y. 1979. Contributions to the dicotyledones plants of Taiwan: 5. – Quart. J. Chin. For. 12: 73–89. Mabberley, D. J. 2008. he plant book. – Cambridge Univ. Press. Mathew, S. P. and Lakshminarasimhan, P. 1990. Rotala andamanensis S. P. Mathew and P. Lakshminarasimhan – a new species of Lythraceae from Andaman Islands. – Bull. Bot. Surv. Ind. 32: 189–191. Pradeep, A. K. et al. 1990. Rotala malabarica, a new species of Lythraceae from India. – Bot. Bull. Acad. Sin. 31: 59–61. Prasad, K. S. and Raveendran, K. 2013. A new species of Rotala L. (Lythraceae) from Kerala, India. – Taiwania 58: 104–107. Prasad, K. S. et al. 2012. Rotala tulunadensis sp. nov. (Lythraceae) from Kerala, India. – Nord. J. Bot. 30: 58–60. Sunil, C. N. et al. 2013. 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