Ixora bawae D. Baro & Bawri, 2025

Baro, Daimalu & Bawri, Amal, 2025, Ixora bawae (Rubiaceae), a new species from Bherjan-Borajan-Padumoni Wildlife Sanctuary, Assam, India, Phytotaxa 701 (3), pp. 294-298 : 295-297

Ixora bawae D. Baro & Bawri sp. nov. ( Fig. 1 ).

Ixora bawae is morphologically close to Ixora cuneifolia Roxb. (1820: 380) and Ixora acuminata Roxb. (1820: 393) in having elliptic leaves, cymes inflorescence, white, glabrous corolla, and drupes didymous. However, the recorded species are distinctly different in having interpetiolar stipules fused with leaves petioles, glabrous, obovate, long spiny at apex, greenish in stem and greenish with light reddish in the base of the inflorescence.

Type:— INDIA. Assam, Tinsukia district, Bherjan -Borajan -Padumoni Wildlife Sanctuary, 27°.52’48.39” N, 95°.36’62.16”, elev. 150 m, 28 May 2022, Baro & Bawri 490 (Holotype CAL! isotypes NEIAFMRH! ARUN!)

Small shrubs 0.5 to 1.5 m in height; branches rounded, glabrous, greenish once young, greyish at maturity, internodes 3–10 cm, one or two branchlets arise from the nodes, stipules 8–11 mm × 3–4 mm, fused with leaves petioles, glabrous, interpetiolar, obovate, with a slender cusp upto 5–6 mm, greenish in stem and greenish with light reddish in the base of the inflorescence. Leaves 12–16.5 cm × 3–6 cm, elliptic, ovate-lanceolate, apex aristate to acute, base cuneate, glabrous, margin crenate, petioles 0.3 cm – 0.6 cm, glabrous, veins are prominent on both sides, lateral veins 7–9 pairs. Inflorescence corymbiform, cymes, terminal and axillary, upto 6 cm long, peduncle 3–5 cm long, glabrous, with a pair of reduced leaves, at the base, 1.3–1.8 cm × 0.2–0.4 cm, oblanceolate, acuminate at the base, reddish in colour, acute to acuminate at apex, greenish, midvein prominent abaxial, secondary veins are prominent both adaxially and abaxially; peduncle ascends3 to 4 rays with 3–4 cluster of pedicellate flowers, each cluster are with 8–10 flowers. Bracts and bracteoles are longer than calyx, soft, reflexed, glabrous, turnip red colour; bract-2, 7–8 mm × 2–3 mm, glabrous, pectinate, linear to lanceolate, margin laciniate, and bracteoles-2, 6–7 mm × 1–2 mm acicular to linear. Calyx ca. 0.5– 0.6 cm × 0.1–0.2 cm, turnip red colour, glabrous, tube 1.5–2 mm, lobes 4, 5 mm long, soft, reflexed, undulate, linear to lanceolate, longer than ovary. Flower white, glabrous, pedicel 3–4 mm long, in bud stage blur pink in the apex, tube 2–2.2 cm long, lobes 0.7 cm × 0.3 cm, ovate-lanceolate; Stamen 4, attached at the base of corolla lobes, alternipetalous, 4mm long, filaments 2mm long, anthers sub-basifixed, curve, 2mm long, brownish. Style slender, 2.2 cm, light pink, stigma 3 mm long fusiform or cuneiform, two lobes, light pink, ovary 2mm long, 2-celled, ovule 1 in each cell. Drupes didymous, ellipsoid, 2–2.3× 0.6–0.8 cm, glabrous, turns red by maturity. Seeds 2 brownish.

Etymology:—The epithet honours Prof. Kamaljit S. Bawa, Distinguished Professor of Biology, University of Massachusetts-Boston for his contribution to the conservation of the Indian Eastern Himalayan Flora.

Phenology:— Flowering from late March to June and fruiting from July–August.

Distribution and ecology:— Ixora bawae is only known from Bherjan -Borajan -Padumoni Wildlife Sanctuary, Assam, India. It grows in a tropical evergreen forest at about 150 m elevation. Less than 50 mature individuals with flowering and fruiting were observed, and the plants were found to be grown in dense forests in shady places with the association of higher plants viz. Aquilaria malaccensis Lam. (1783: 49) , Dillenia indica L. (1753: 535), Ficus religiosa L. (1753: 1059) and Magnolia hodgsonii (Hook. f. & Thomson) H. Keng (1978: 129) .

Conservation status:— The species existed with a few fragmented populations in the type locality. The total known population is estimated to consist of about 60–70 individuals. The extent of occurrence is less than 10 km 2. Major threats include overgrazing by wild animals. Based on this information we assess this taxon as Critically Endangered (CR B1ab (iii) under the IUCN’s Categories and Criteria ( IUCN 2001, 2012). Immediate conservation efforts are necessary to prevent its extinction.

NOTES. The presently reported novel taxon is only known from Bherjan -Borajan -Padumoni Wildlife Sanctuary, Assam, India. It grows in a tropical evergreen forest in two plots with a few fragmented populations. Ixora bawae is morphologically close to Ixora cuneifolia Roxb. (1820: 380) and Ixora acuminata Roxb. (1820: 393) in having elliptic leaves, cymes Inflorescence, white, glabrous corolla, and drupes didymous. However, the recorded species is distinctly different in having interpetiolar stipules fused with leaves petioles, glabrous, obovate, long spiny at apex, greenish in stem and greenish with light reddish in the base of the inflorescence; terminal, axillary inflorescence, leaves apex aristate to acute, glabrous, pectinate laciniate bracts and acicular to linear bracteoles, longer than calyx tube, turnip red colour, soft, reflexed, undulate calyx, with 4 lobes, 5 mm long, glabrous, linear to lanceolate, longer than ovary ( Table 1).

Figures

FIGURE 1. Ixora bawae—A & B. Habit, C. Mature Fruit, D. Soft reflexed calyx lobe, E. Bracteoles, F. Bracts, G. Single flower, H & I. Calyx tube & lobes, J. Corolla lobes, K. Longitudinal section of fruit, L. Gynoecium, M. Stamen with curve anther lobe, N. Interpetiolar stipules fused with leaves petiole, O. Leaves with length variation.