Oldenlandia smita-crishnae Nandikar & K.C.Kishor, 2019

Nandikar, M. D. & Kishor, K. C., 2019, A new species and a synopsis of the Hedyotis-Oldenlandia group (Rubiaceae: Spermacoceae) in Andaman & Nicobar Islands, India, Blumea 64 (3), pp. 225-230 : 226-229

Oldenlandia smita-crishnae Nandikar & K.C.Kishor , sp. nov. — Fig. 1 , 2

Type: M. D. Nandikar & K. C. Kishor 2118 (holo CAL; iso K, NGCPR, PBL), India, Andaman & Nicobar Islands, North Andaman, Saddle Peak National Park, N13.15 '541" E093.01 '884", elevation 513 m a.s.l., 7 Oct. 2017 .

Etymology. Named after Mrs. & Mr. Crishna (Smita Godrej Crishna and Vijay Mohan Crishna), Directors of the Naoroji Godrej Centre for Plant Research in Shirwal, Satara, India, to honour their promotion of plant taxonomy and conservation.

Erect, 5–20 cm high, annual or perennial herb. Roots thin, fibrous, often with woody rootstock. Stem usually branched,terete, light green tinged with pink, glabrous. Leaves stipulate, stipule divaricate with two small basal projections, 1.5–2.5 by 0.1–0.3 mm, ligulate, sparsely toothed on the margin; leaf lamina sessile, linear-elliptic or lanceolate, 1–2 by 0.1–0.3 cm, apex acute, base attenuate, margin puberulent, adaxially glabrous, abaxially puberulous. Inflorescence axillary, solitary or a 2-flowered cyme. Flower pedicellate, pedicel 1–2 cm long, glabrous, filiform; flower homostylous, 6–7.5 mm long; hypanthium obovoid, 1–3 by 0.5–1.5 mm; calyx lobes 4, lanceolate, base obtuse, green with pink tinge, margin with small setae, pink, midrib prominent; corolla infundibuliform, 4–5 mm long; tube slender, 1–2 mm long, white, glabrous without and sparsely to densely puberulous within (at throat); lobes 4, elliptic-lanceolate, 2–2.5 by 0.3–1 mm, apex acuminate, white with pink aciculated, glabrous without and double lined pink-striped, sparsely puberulent within (densely at margin). Stamens 4, included, filament inconspicuous; anther linear to oblong, 0.8–1 mm long, erect, equal, bilobed, adnate to corolla tube, dorsifixed; pollen periporous, 100–130 by 90–100 µm, prolate-spheroidal to subprolate in shape. Ovary globose or ovoid, 1.5–2 mm across, glabrous; style slender, 3–4 mm long, glabrous; stigma bilobed, exceed- ing corolla tube. Capsule globose or ovoid, 2–2.5 by 1–1.5 mm, bilocular, crowned by persistent protruding calyx lobes. Seeds 20–30 per capsule, outline deltoid, 0.3–0.4 by 0.1–0.2 mm, ventrally ellipsoid, dorsally obovoid, testa reticulate-foveate, shiny, dark greyish brown, hilum punctiform.

Phenology — Flowering and fruiting throughout the year, but peak during October.

Distribution & Ecology — An endemic to the Saddle Peak National Park, North Andaman, Andaman & Nicobar Islands, India. It grows abundantly in an open scrub forest of the Saddle Peak forest of North Andaman, mainly preferring open rocky situations of the mountain peak at an elevation of 500 –540 m a.s.l. The associated plant species include Crotalaria uncinella Lam. subsp. elliptica (Roxb.) Polhill , Dioscorea belophylla (Prain) Voigt ex Haines , Grewia indandamanica J.L.Ellis & L.N.Ray , Memecylon umbellatum Burm.f. , Murdannia saddlepeakensis M.V.Ramana & Nandikar and Sonerila andamanensis Stapf & King.

Conservation status — An estimation of area of occurrence ( AOO) of the species is unworkable, as some of the forest patches of the Saddle Peak National Park are inaccessible. Therefore, it is here assessed as Data Deficient ( DD), using the criteria of IUCN (2017). The first collection of Oldenlandia smita-crishnae was in 2001 (Sumathi 17367, PBL) labelled as ‘abundantly distributed’, we also found the species growing abundantly and one of the commonest herbaceous elements in open, rocky situations of the hilltop, and apparently not under threat.

Additional material examined (paratypes). INDIA, Andaman & Nicobar Islands , North Andaman,Saddle Peak, R . Sumathi 17367 ( PBL0000010026 , PBL0000010027 ), 18 Apr. 2001 .

Notes — Oldenlandia smita-crishnae is similar to O. corymbosa , O. pseudocorymbosa and O. herbacea in a combination of characters like erect or prostrate habit, sessile to subsessile leaves and globose to ovoid ovary. However, the new species can be easily distinguished by the abaxially puberulous leaf, divaricate stipules, obovoid hypanthium, pink-striped corolla lobes, puberulous tube, inserted and 20–30 seeded capsules. A detailed comparison of O. smita -crishnae with O. herbacea , O. corymbosa and O. pseudocorymbosa is given in Table 1.

Oldenlandia smita-crishnae is also similar to O. affinis and O. graminicola in flower size and shape but the latter two differ by having terminal dichasial cymes and lax panicles. Moreover, O. graminicola has an angular stem, truncate stipules and scabrid pedicels, while O. smita -crishnae has terete stems, divaricate stipules and glabrous pedicels.

Oldenlandia horneriana Miq. (non Kuntze), an endemic species of Sumatra also shares similarities with O. smita -crishnae in being an annual with erect habit, linear leaves and infundibuliform corolla, but mainly differs in having angular stem, and distinctly exerted anthers.

Figures

Fig. 1 Oldenlandia smita-crishnae Nandikar & K.C.Kishor. a. Habit; b. stipule; c. flower; d. opened corolla with adnate stamens; e. capsule; f. pistil with hypanthium; g. seeds (ventral and lateral view) (all M.D. Nandikar & K.C. Kishor 2118, CAL). — Scale bars: a–b, e = 1 mm; c = 1.2 mm; d = 0.6 mm; f = 0.7 mm; g = 0.8 mm. — Drawn by Mayur D. Nandikar.

Fig. 2 Oldenlandia smita-crishnae Nandikar & K.C.Kishor. a. Habitat from Saddle Peak National Park; b. habit; c. upper view of flower; d. lateral view of flower. — Photos by Mayur D. Nandikar.