Cyperus coonoorensis Viji, Pandur., Deepu & G.C.Tucker, 2015

Viji, Ambika Rajan, Pandurangan, Alagramam Govindasamy, Deepu, Sivadas & Tucker, Gordon C., 2015, Cyperus coonoorensis (Cyperaceae), a new species from the Nilgiri Biosphere Reserve, India, Phytotaxa 203 (2), pp. 178-184 : 178-181

Cyperus coonoorensis Viji, Pandur., Deepu & G.C.Tucker , sp. nov. ( Fig. 1 & Fig. 2 )

Type:— INDIA. Tamil Nadu: Nilgiri Distr., Coonoor , 11°20´59´´N & 75°49´10´´E, ± 1501 m, 24 March 2012, A. R. Viji & A. G. Pandurangan 72342 (holotype TBGT!; isotypes CALI!) .

Robust perennial herbs, 0.6–1m high. Rhizomes 3–4 cm long, 2–2.5 cm wide. Culms 1–2 per plant, 45–80 cm tall, 0.3–0.7 cm thick at mid height, stout, striate, smooth, sharply triangular; the bases surrounded by firm, purplish brown, old leaf sheaths. Leaves basal, 3–5 per culm; sheaths 4–10 cm long, purplish brown towards the base; blades 30–70 × 1–2 cm, green, flat, rigid, with 3 prominent nerves, gradually narrowed towards apex, scaberulous near margin towards apex. Inflorescences decompound to supra-decompound, diffuse, dense, 20–35 × 25–35 cm; involucral bracts 8–12, spreading, arranged in 2–3 whorls, unequal, leaf-like, with 3 prominent nerves, 6–75 cm long, 0.5–2 cm wide; primary rays many, spreading, unequal, 5–30 cm long, smooth, angular; secondary rays spreading, slender, smooth, angular, 2–10 cm long; tertiary rays 1–4 cm long. Spikelets 6–10 together, compressed, linear, 1–1.5 × 0.15–0.2 cm, 20–32 flowered; pedicels 0.8–1 mm long; rachilla completely covered by glumes; glumes closely imbricate, membraneous, boat-shaped, broadly ovate to suborbicular, obtuse and mucronate apex, 1.7–2 × 1.3–1.5 mm (including 0.3–0.5 mm mucro), keeled; keel with prominent mid vein, sides faintly nerved, whitish-hyaline at margins, brown spotted. Stamens 3, ca. 1 mm long; anthers linear, 0.5 mm long, acute crest on apex; filaments ca. 0.5 mm long. Ovary ellipsoid, ca. 1 mm long; style minute, ca. 0.3 mm long; stigma 3, ca. 1 mm long, shortly exerted from glume. Nutlets ellipsoidal, trigonous, 1–1.3 × 0.5–0.7 mm, smooth, minutely apiculate, dark brown.

Comparison:—The diagnostic differences between C. diffusus and C. coonoorenis are detailed ( Table 1).

Distribution:— India, Tamil Nadu, Nilgiri District in Nilgiri Biosphere Reserve, is located in the Western Ghats (11°30’– 12°0’N and 76°0’– 77°15’E) and falls at the tri-junction of the states of Karnataka, Kerala and Tamil Nadu of the Indian Union. The reserve is extended to 5520 km 2 within the tropical forest biome which portray the confluence of Afro-tropical and Indo-Malayan biotic zones of the world. It consists of mountain ranges in varying elevation from 300 to 2655 m and host different ecosystems ranging from seasonal rainforests in the low hills, tropical montane forests and grasslands in the higher reaches and moist deciduous to scrub through dry-deciduous forests in plains. It is one of the noted ‘hot spots’ for speciation in the tropics due to the rich endemism and unique flora and fauna ( Fig. 3 ).

Etymology:—The specific epithet “ coonoorensis ” is derived from the name of type locality “Coonoor” located within the Nilgiri Biosphere Reserve.

Habitat:—Occurs at an altitude of ± 1501 m in moist shady areas. The associated species in the community are Cyperus iria L. (1753: 45), C. diffusus , Kyllinga melanosperma Nees (1834: 91) , K. brevifolia Rottb. (1773: 13) , Digitaria setigera Roth (1817: 474) , Eranthemum capense L. (1753: 9) etc.

Phenology:—Flowering and fruiting was observed from November to April.

Conservation Status:—Being found in open areas, this species is generally removed along with other weeds as part of maintenance of plantation crops. According to IUCN criteria ( IUCN 2012a & b, 2013), the extent of occurrence (EOO) is less than 10 km 2 and the area of occupancy (AOO) is less than 0.5 km 2, and there are less than 250 individuals in the population, which indicates its narrow endemic nature. Therefore we recommend a preliminary conservation assessment as Critically Endangered: CR – B1a; B2a; C2a(ii).

Recognition:— Cyperus coonoorensis belongs to sect. Diffusi of the genus Cyperus by having broad leaves and bracts, and subquadrangulate spikelets in digitate clusters of 1–6. The section Diffusi includes about 43 species, found worldwide in tropical regions ( Tucker 2007). In southern Asia, six species are known so far (Kükenthal 1935–36, Simpson 1998, Tucker 2007). The new species, C. coonoorensis can be distinguished readily from each of these; C. multispicatus Boeckeler (1874: 362) has a single stamen per flower, and C. kurzii C.B. Clarke (1884: 129) and C. helferi Boeckeler (1874: 360) have two stamens per flower; C. coonoorensis has three stamens per flower (as do most species of the genus). Cyperus radians Nees & Meyen ex Kunth (1837: 95) of southeastern Asia ( Dai et al. 2010, Simpson & Koyama 1998) has the primary branches (rays of the inflorescence) much longer than the culm, and it is thus unlikely to be confused with C. coonoorensis or other Asian species of Cyperus . Cyperus thorelii E.G. Camus (1910: 242) is known from Vietnam, and has a simple inflorescence with few spikelets, unlike the richly branched inflorescence of C. coonoorensis . Cyperus diffusus (including var. latifolius and subsp. macrostachyus ) have some similarity to this new species in the shape of the glumes and the wide leaves ( Fig. 4 ). However, C. diffusus has glumes prominently nerved laterally, unlike C. coonoorensis , and has longer anthers (0.8–1 mm). Also, C. diffusus lacks 3–4° branching in the inflorescence, which is a feature the new species shares with C. matudae G.C. Tucker (1986: 503) and C. costaricensis Gómez-Laur. in Gómez & Gómez-Laurito (1982: 228) of tropical America ( Tucker 1994). Some African species, such as C. ajax C.B. Clarke (1901: 343) and C. glaucophyllus Boeckeler (1888: 4) have broad leaves and 3° branching ( Haines & Lye 1983), but neither matches C. coonoorensis exactly in other features such as glume length or number of scales. For example, C. ajax has spikelets with about 10 flowers, while new species has 20–32; C. glaucophyllus has culms scabrous on the angles and sessile achenes, while C. coonoorensis has smooth culms and stipitate achenes. To illustrate these differences, an identification key to all species of Cyperus in sect. Diffusi known from South Asia is presented.

Figures

FIGURE 1. Cyperus coonoorensis sp. nov. A. Spikelet, B–C. Glumes, D. Stamen, E. Pistil, F, Nutlet. (Photos from Holotype by Deepu)

FIGURE 2. Cyperus coonoorenisis sp. nov. A. Habit, B. Spikelet, C–D. Glumes, E. Stamen, F. Pistil, G. Nutlet. (Drawn from Holotype by Deepu)

FIGURE 3. Cyperus coonoorenisis sp. nov. distribution map.

FIGURE 4. Type sheets of Cyperus. Sect. Diffusi of South Asia. A. C.diffusus Vahl (K000290906!); B. C. multispicatus Boeck. (C10012256!); C. C. helferi Boeck. (K000592541!); D. C. kurzii Clarke (CAL503254!); E. C. thorelii E. Camus (P00587073!); F. C. radians Nees & Meyen (K000290898!); G. C. coonoorensis Viji, Pandur. Deepu & G.C. Tucker. (TBGT72342!)