Rubus ramachandrae S.S.Dash & Chand.Gupta, 2018

Gupta, C. & Dash, S. S., 2018, A new species of Rubus (Rosaceae) from Arunachal Pradesh, India, Blumea 63 (1), pp. 26-30 : 26-29

Rubus ramachandrae S.S.Dash & Chand.Gupta , sp. nov. — Fig. 1–4 ; Map 1

Rubus ramachandrae is similar to Rubus stipulosus and R. fuscifolius , but differs by having densely bristly or hirsute branches;narrowly ovate to oblong-lanceolate leaves with caudate-acuminate apex;adaxially hirsutulous vesture of leaves; broadly ovate to suborbicular, foliaceous, persistent stipules with irregularly and deeply biserrate margin; hirsutulous and fulvous-tomentose floral bracts and obovate petals. — Type: S.S.Dash & Chandani Gupta 65482 (holo CAL;iso CAL,ARUN, ASSAM), India, Arunachal Pradesh, Upper Sub- ansiri district,between Daporijo and Raga village, E94°11'42.5 N27°49'23.4, 1 270 m alt., 15 Aug. 2015. – Paratype: S.S. Dash & Chandani Gupta 67403 (BSD,CUH), near La village, 35 km from Daporizo, E94°13'32.3 N27°51ʹ42.7, 1 260 m alt., 9 Aug. 2016.

Etymology. The species is named in loving memory and reverent regards of Sri Rama Chandra Dash, father of corresponding author, who was a constant source of encouragement and motivation during all field work in the difficult terrain in Arunachal Pradesh.

Shrubs, straggling, to 3 m tall. Stems terete, erect or procumbent, woody, densely bristly or hirsute mixed with reflexed strong prickles, green, bristles white becoming brown in age, internodes 4.5–6 cm long. Stipules foliar, broadly ovate to suborbicular, 1.5–3 by 2–2.5 cm, apex acute, margin irregularly deeply biserrate, glabrous adaxially hirsutulous or densely pilose abaxially, brown, palmately 10–12-veined, persistent or rarely late caducous. Petioles slender, 3–4 cm long, densely hirsute, with short stout reflexed prickles, green. Leaves alternate, simple, narrowly ovate or oblong-lanceolate, shallowly 3- or 5- (or 7-)lobed, lowest two lobes often differentiated, upper lobes scarcely differentiated,12–15 by 6–9 cm, apex narrowly acuminate to caudate-acuminate, acumen 1.5–2 cm long; apex of lobes acute, margin irregularly biserrate, constricted at lobes; base deeply cordate, 3–5-veined at base, principle vein with 5 or 6 pairs of lateral veins; adaxially hirsutulous, more densely so along veins, green, dark brown when dry; abaxi- ally grey tomentose, becoming fulvous-tomentose when dry. Inflorescences terminal thyrse and axillary thyrse, subracemose or corymbose, terminal inflorescences up to 18 cm long, more than 20-flowered, axillary inflorescences shortened, 5 –12 cm long, laxly flowered; rachis hirsute, mixed with minute needle shaped prickles; involucral bracts 2, foliar, 1.3–1.8 by 0.8–1.2 cm, broadly ovate, apex acute, margin serrate or serrate only near apex, adaxially glabrous, abaxially hirsutulous; sparsely strigose near base, brown; pedicels slender, 3–12 mm long, subtended by 2 floral bracts, hirsute; ovate or ovate-oblong, 4–10 by 1–8 mm, almost covering the buds, apex acute, margin entire or with very few serrations apically, abaxially densely pubescent to hirsutulous, mixed strigose at base, adaxially glabrous, green, brown at maturity. Flowers bisexual, actinomorphic, 0 .8 –13 mm across; hypanthium perigynous; calyx green, more or less bell-shaped or narrowly campanulate, united at base to 1–3 mm long, lobes 5, ovate to ovate-lanceolate, 10–12 by 3–4 mm, apex caudate-acuminate, outer lobes 2- or 3-fid or laciniate, inner lobes entire, abaxially densely tomentose, adaxially sericeous from middle to apex, margin of outer lobes with white hairs; petals white, 5, obovate, 6 by 4 mm, base clawed, claw 1–1.5 mm long, margin entire, erose only near apex, apex abruptly pointed, sparsely hairy on outer surface, inner surface glabrous; stamens numerous, almost equal in size, in several series, shorter than petals and pistils; filaments round or flattened, c. 3 mm long, glabrous, pale white, anthers 2-celled, c. 0.5 mm long, dorsifixed, sparsely hairy, yellow, dehiscence longitudinally introrse; carpels many, ovary lunate, c. 1 mm long, glabrous, short stalked, style subterminal, c. 1 cm long, glabrous, white, stigma capitate, torus convex, to 2 mm long, with few stiff hairs basally.

Pollen morphology — Pollen grains 3-colporate, prolatespheroidal (P/E ratio: 1.04) 24–25 μm in polar length with round- ed, often emarginate ends, colpus narrow, distinctly uniform along the poles, extending over 90 % of the polar axis, equato- rial bridge distinct, margins constricted at equator and elevated. The colpus membrane is covered with rugged granulations and undulate. The endoaperature is smooth, indistinct and usually hidden under the rugged exine or equatorial bridge. The exine layer is thick and finely ornamented. The surface ornamentation is finely verrucose-foveolate. The punctum consists of more or less rounded depressions and narrow and often anastomosing elongated verrucae, more often creating a perforated suprarugulate tectum ( Fig. 4 ).

Distribution — India, Arunachal Pradesh; known only from the type and its adjacent locality ( Map 1 ).

1

i iicb

Fig. 2 Rubus ramachandrae S.S.Dash & Chand.Gupta. a. Flowering twig;

b. abaxial surface of stipules; c. abaxial surface of bracts (i: margin serrated

near apex,ii: margin entire); d. flower;e. longitudinal section of flower; f. free

lobes of calyx (i–iv. adaxial surface; v. abaxial surface); g. petal; h. stamen;

i. pistil. — Drawn by Chandani Gupta.

Habitat & Ecology — Rubus ramachandrae grows in open subtropical forests between 1 100 and 1 300 m.

Flowering & Fruiting — July to September.

Provisional IUCN conservation assessment — Rubus ramachandrae is known only from two localities in Upper Subansiri in Arunachal Pradesh, India. During our study, we located only two gregarious patches 5 km apart with 4 or 5 mature plants each. The species has not been collected elsewhere, hence, its provisional conservation status may be considered Data Deficient ( IUCN 2017) .

Note — Due to the presence of straggling shrubby habit, free stipule, simple leaves, with both needle shaped and reflexed prickles, various forms of panicled axillary and terminal inflorescences and the more or less bell-shaped or campanulate calyx, it is proposed here that R. ramachandrae be placed in Rubus subg. Malachobatus Focke ( Focke 1910: 41), a subgenus of about 115 species ( Focke 1910, 1911, 1914, Kalkman 1993, Lu & Boufford 2003) mainly concentrated in tropical and sub- tropical regions of the Asian continent.

Figures

Map 1 Map showing place of collection of Rubus ramachandrae from Upper Subansiri district, Arunachal Pradesh, India.

Fig. 1 Image of holotype of Rubus ramachandrae S.S.Dash & Chand.Gupta.

Fig. 3 Field photographs of Rubus ramachandrae S.S.Dash & Chand.Gupta. a. Habit; b. inflorescences; c. stipules (inset: juvenile stipule); d. closer view of flower. — Photos by S.S. Dash.

Fig. 4 Pollen morphology of Rubus ramachandrae S.S.Dash & Chand.Gupta. a–d: SEM images; e–g: LM images. a. Equatorial view of pollen; b. polar view of pollen showing tricolporate aperture; c. closer view of aperture showing endoaperture and the surface ornamentation; d. closer view of aperture with bridge; e, f. subpolar view showing endoaperture with bridge; g. subequatorial view (arrow showing colporate aperture).