Journal of Threatened Taxa | www.threatenedtaxa.org | 26 June 2023 | 15(6): 23458–23460

ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print)

https://doi.org/10.11609/jott.8314.15.6.23458-23460

#8314 | Received 08 December 2022 | Final received 18 May 2023 | Finally accepted 27 May 2023

Eleocharis acutangula ssp. neotropica D.J.Rosen (Cyperaceae): a new record for southern Western Ghats, India

Kavya K. Nair ¹ & A.R. Viji ²

¹ PG Department of Botany, Christian College, Kattakada, Thiruvananthapuram, Kerala 695572, India.

² PG Department of Botany, Iqbal College, Peringammala, Thiruvananthapuram, Kerala 695563, India.

¹ kavyaknair1609@gmail.com (corresponding author), ² vijihari1982@gmail.com

Editor: V. Sampath Kumar, Botanical Survey of India, Coimbatore, India. Date of publication: 26 June 2023 (online & print)

Citation: Nair, K.K. & A.R. Viji (2023). Eleocharis acutangula ssp. neotropica D.J.Rosen (Cyperaceae): a new record for southern Western Ghats, India. Journal of Threatened Taxa 15(6): 23458–23460. https://doi.org/10.11609/jott.8314.15.6.23458-23460

Copyright: © Nair & Viji 2023. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use, reproduction, and distribution of this article in any medium by providing adequate credit to the author(s) and the source of publication.

Funding: None.

Competing interests: The authors declare no competing interests.

Acknowledgements: Authors are thankful to the Pricipal and Head of the Department of Botany, Christian College, Kattakada for providing necessary facilities.We also acknowledge Central Laboratory for Instrumentation and Facility (CLIF), University of Kerala for providing provision for SEM analyses. And the first author is thankful to University of Kerala for providing fellowship assistance.

The genus Eleocharis R.Br. comprises about 300 species distributed in tropical and temperate regions of the world (Govaerts et al. 2021). In India, the genus is represented by 28 species (Prasad et al. 2020) in which 19 are reported from the Western Ghats (Nayar et al. 2014). As part of taxonomic revision of the genus Eleocharis in the Western Ghats, the authors collected some interesting specimens from the wetlands of the Kollam district of Kerala. On critical examination and scrutiny of literature, it was identified as Eleocharis acutangula (Roxb.) Schult. ssp. neotropica D.J.Rosen.

Scirpus acutangulus Roxb. was described by Roxburgh (1820) based on specimens from India. Schultes (1824) transferred it in to Eleocharis and made the combination Eleocharis acutangula (Roxb.) Schult. Later, Svenson (1939) and Browning et al. (1997) suggested the existence of variability among specimens of E. acutangula from different geographical areas. Rosen et al. (2007) suggested sufficient variation existed among specimens of worldwide collections of E. acutangula and they segregate into three infraspecific taxa: E. acutangula ssp. acutangula, E. acutangula ssp. breviseta D.J.Rosen, and E. acutangula ssp. neotropica D.J.Rosen based on multivariate statistical analysis, ecological and distributional data. Recently, Prasad et al. (2020) in their checklist placed both the subspecies as the synonym of E. acutangula ssp. acutangula. But the specimens which were collected from Kollam district of Kerala is found quite distinct from subspecies acutangula and detailed taxonomic studies with fresh collections and original protologue (Rosen et al. 2007) clearly depict the existence of characters of ssp. neotropica and needs a taxonomic recognition as subspecies and therefore we reinstated its status.

Eleocharis acutangula (Roxb.) Schult. is a widespread species found in a wide range of habitats throughout India (Prasad et al. 2020). Scrutiny of literature revealed that subsp. neotropica was not reported from southern Western Ghats earlier but known from northern Western Ghats regions of India (Chandore 2015). Hence, the present collection extends its known distribution range to the southern Western Ghats, forming an addition to the flora of Kerala state. A detailed description along with photographs of the species is provided here for easy identification. The key characters to distinguish these two subspecies are mentioned in the Table 1.

Taxonomic treatment

Eleocharis acutangula (Roxb.) Schult. subsp. neotropica D.J.Rosen, J. Bot. Res. Inst. Texas 1(2): 886.2007.

Type: Peru, Departamento de Loreto, Maynas, Iquitos, prolongacion Yavari, Versailles-Paina, open annually burned grassland, 23 March 1974, McDaniel & Rimachi 18552 (Holotype:- MO 324923 image!)

Perennial herbs; rhizomes short with fibrous root. Culms triquetrous, tufted, erect, 45-–80 × 0.3–0.4 cm internally spongy, soft, with incomplete transverse septa, pale green. Leaf reduced to sheath, 2, ca.15 cm long, mucronate at apex, brownish. Inflorescence, a terminal spike, cylindric, 3–3.5 × 0.28–0.3 cm, many-flowered, acute. Glumes oblong-ovate, ca. 5 × 3.7 mm, all fertile, abaxially many veined with adaxially distinguishable prominent midvein, apex acute. Hypogynous bristles 6, 2–2.4 times longer than nut, unequal, retrorsely scabrid, ca. 4 mm long. Stamens 3; anthers linear, 1–1.5 mm long. Style 3 fid. Nut biconvex, shining yellow tinged with amber, ca. 1.5 × 1.6 mm, style base persistent, dark brownish, conical, ca. 0.6 mm long (Image 1).

Flowering & Fruiting: June to August.

Specimen collected: 5110, 12 vii 2022. India, Kerala, Kollam District, Nilamel (8.8238⁰N, 76.8824⁰E), coll. Kavya K. Nair & A. R. Viji, TBGT

Note: The Scanning Electron Microscopic studies on the nut revealed the presence of elongated hexagonal epidermal cells with ca. 15 rows of transverse cells on one side of the nut. The periclinal walls are thick and straight in appearance.

Table 1. Diagnostic characters of E. acutangula ssp. neotropica and ssp. acutangula.

E. acutangula ssp. neotropica	E. acutangula ssp. acutangula
Longest perianth bristle up to 4 mm long, soft, flexous, spinulose to below the middle	Longest perianth bristle up to 3.2 mm long, stiff, spinulose throughout or smooth
Nut neck weakly constricted	Nut neck markedly constricted
Style base up to 0.6 times long as wide	Style base up to 1.1 times long as wide
Mature Nut yellow green tinged with amber	Mature Nut dark amber to dark brown

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References

Browning, J., K.D.G. Gray & C.J. Ward (1997). Studies in Cyperaceae in Southern Africa 32: Eleocharis subgenus Limnochloa. South African Journal of Botany 63(4): 172–184. https://doi.org/10.1016/S0254-6299(15)30741-9

Chandore, A.N. (2015). The genus Eleocharis R.Br. in North Western Ghats with four new records and its importance for ecosystem, pp. 66–71 . In: International Conference on Ethical Prospects: Economy, Society and Environment. University of Mumbai, Maharashtra.

Govaerts, R., J. Koopman., D.A. Simpson, K. Wilson, T. Egorova & J.J. Bruhl (2021). World checklist of selected plant families. http://wcsp.science.kew.org/reportbuilder.do. Royal Botanic Garden. Retrieved on 15 March 2023.

Nayar T.S., M. Sibi & A.R. Beegam (2014). Flowering Plants of the Western Ghats, India. Vol.2. Monocots. JNTBGRI, India.

Prasad, V.P., S.D. Chowdhury, B. Jana & A. Maji (2020). Cyperaceae, pp. 249–300. In: Mao, A.A. & S.S. Dash (eds.). Flowering Plants of India, an annotated checklist (Monocotyledons). Botanical Survey of India, Kolkatta, 545 pp.

Rosen, D.J., R. Carter & S.L. Hatch (2007). Infraspecific taxonomy and nomenclature of Eleocharis acutangula (Cyperaceae). Journal of the Botanical Research Institute of Texas 1(2): 875–888.

Roxburgh, W. (1820). Flora Indica or Descriptions of Indian plants. Serampore, Mission Press, 493 pp.

Roemer, J.J. & J.A. Schultes (1824). Systema Vegetabilium 2. Stuttgardtiae. Sumtibus J.G. Cottae, 388 pp + errata 4 pp.

Svenson, H.K. (1939). Monographic studies in the genus Eleocharis V. Rhodora 41: 1–19.