Ophiorrhiza sahyadriensis Hareesh, V.B. Sreek. & K.M.P. Kumar, 2015

Hareesh, V. S., Sreekumar, V. B., Prabhu Kumar, K. M., Nirmesh, T. K. & Sreejith, K. A., 2015, Ophiorrhiza sahyadriensis (Rubiaceae), a new species from southern Western Ghats, Kerala, India, Phytotaxa 202 (3), pp. 219-224 : 220-223

Ophiorrhiza sahyadriensis Hareesh, V.B. Sreek. & K.M.P. Kumar , sp. nov. ( Figs. 1 and 2 )

The new species is similar O. brunonis in its glabrous, ovate, elliptic to lanceolate leaves, sub-corymbs with puberulous rachis, linear-lanceolate, puberulous, persistent bract and bracteoles, heterostylous flowers, corolla white, pubescent outside, with a villous ring inside, and ovate or linear-lanceolate stile branches, from which it differs in having shorter flowers with shortly keeled corolla lobes (vs. not keeled), corolla densely pubescent at distal portion and with a villous ring inside (vs. glabrous at basal and distal portion inside), anthers 15– 2 mm long (vs. 2–3.5 mm long), and obovate, pubescent style branches in longistylous flowers (vs. ovate-lanceolate, glabrous in longistylous flowers).

Type:— INDIA. Kerala: Palakkad district, Silent Valley, Walakkad , 1100 m, 11º 8’52.58’’ N, 76 o 24’ 57.63’’ E, 15 December 2011, V. S. Hareesh 28501 (holotype, KFRI; isotypes, CALI, CMPR, KFRI, MH)

Erect herb, 15–60 cm tall; stem branched, woody at base, terete, puberulous when young, glabrate at older stage, green; internodes 1.5–9 cm long. Stipules linear with broad base, entire, 3–12 mm long, acute, puberulous, caducous. Petioles 2–4 cm long, slender, glabrous or puberulous; leaf blades ovate, elliptic to elliptic-lanceolate, 3–16 × 1.5–6.5 cm, attenuate at base, caudate acuminate at apex, glabrous or scabrous above; secondary veins 8–13 each side, glabrous or puberulous below. Inflorescence axillary, sub-corymbose, 1.5–3 cm in diameter; rachis puberulous; peduncle 3–6 cm long, slender, pubescent; bract and bracteoles similar, linear-lanceolate to filiform, 3–5 mm long, puberulous, persistent. Pedicels 0.5–1 mm long, puberulous. Flowers 8–11 mm long, pubescent. Hypanthium obovoid, 0.6–1 × 0.6–0.8 mm; disc 0.5–0.6 mm tall, pubescent. Calyx lobes ovate-lanceolate, 0.9–1 × 0.45–0.5 mm, green or pale green, acute, pubescent, glabrous on adaxial side. Corolla infundibuliform, 6–7 mm long, white, pubescent outside, densely pubescent inside with a ring of villous hairs at the middle of tube, glabrous below the ring inside, prominently veined; lobes ovate-lanceolate, 1.5–1.75 × 1–1.25 mm, acute, shortly keeled on back, spreading, densely puberulent. Shortstylous flowers: stamens exerted, inserted at the middle of corolla tube; filaments 1–1.25 mm long; anthers oblonglinear 1.5–2 mm long; style filiform, 0.5 mm long, glabrous; style branches 2, linear lanceolate, 1 mm long, glabrous. Longistylous flower: stamens inserted near the base of the corolla tube; filaments 0.25–1 mm long; anthers oblonglinear, 1.5–2 mm long; style filiform, 2–2.5 mm long, glabrous; style branches 2, round to obovate, 0.06–0.8 × 0.4–0.5 mm, pubescent. Capsules obcordate in outline, 3–3.5 × 5–9 mm, glabrous, green; seeds many, angular, brown.

Flowering and fruiting: — From November to July.

Eponymy:— The specific epithet is named after the type locality Sahyadri Hills,Western Ghats, India.

Distribution, Ecology and Biotic association: — Ophiorrhiza sahyadriensis is known only from the evergreen forest of Silent Valley National Park and Muthikulam, southern Western Ghats, Kerala, India. Healthy populations were observed in four areas viz. Walakkad, Sispara, Anguinda, Muthikulam waterfalls and the western slopes of Velliangiri hills at 1100–2300 m altitude. The new species is probably endemic to this area and grows in small pockets in moist shady places and besides streams along with Amomum ghaticum Bhat (1988: 322) , Argostemma courtallense Arnott (1839: 22) , Cullenia exarillata Robyns (1970: 249) , Impatiens munronii Wight (1840: 160) , Memecylon sisparense Gamble (1919: 227) , Ophiorrhiza hirsutula Wight ex J. D. Hooker (1880: 81) , Palaquium ellipticum ( Dalzell 1851: 36) Baillon (1884: 1500) , Plectranthus malabaricus ( Bentham 1830: 16) R. H. Willemse (1979: 509) , Schumannianthus virgatus ( Roxburgh 1810: 324) Suksathan & Borchs (2009: 393) , Sarcandra chloranthoides Gardner (1846: 348) and Vateria macrocarpa Gupta (1929: 231)

Conservation status: — Known from only four localities and with an extent of occurrence estimated to be less than 100 km 2. So far, in these localities we encountered populations of approximately 100 individuals. Therefore, the status is here assessed as Data Deficient (DD), and more field studies are necessary to assess its conservation status ( IUCN 2012).

Additional specimens examined (paratypes): — INDIA. Kerala: Palakkad district, Silent Valley, Sispara , 2150 m, 25 July 2012, V. S. Hareesh & V. B. Sreekumar 28525 ( KFRI) ; Walakkad , 1100 m, 1 November 2013, V. S. Hareesh & V. B. Sreekumar 28850 ( KFRI) ; Muthikulam falls , 1350 m, 23 November 2013, V. S. Hareesh & K. M. Prabhu Kumar 28851 ( KFRI) ; Muthikulam falls , 1350 m, 23 November 2013, K. M. Prabhu Kumar & V. S. Hareesh 7772 ( CMPR) .

Figures

FIGURE 1. Ophiorrhiza sahyadriensis. A. Habit. B. Flower, side view. C. Open corolla, showing stamens and pubescent ring. D. Hypanthium and stamens. E. Short-stylous flowers showing hypantium and style. F. Long-style flower, showing hypanthium and style. G. Stamens, dorsal and ventral views. H. Fruit. Drawn after V.S. Hareesh 28501 by V.S. Hareesh.

FIGURE 2. Ophiorrhiza sahyadriensis. A. Habit. B. Inflorescence. C. Branchlet of the inflorescence. D. Flower, side view. E. Flower Buds. F. Pedicel, hypanthium and calyx, with bract and bracteole. G.–J. Floral parts, showing heterostyly. G. & H. Corolla-split open. I. Stamens. J. Hypanthium, calyx, and style of two flowers. K. Young fruit, side view. Photos by K.M. Prabhu and V.S. Hareesh