Symplocos mohananii J.Stephan, R.Akhil & P.W.Fritsch, 2021

Stephan, Jeyamary, Fritsch, Peter W. & Akhil, Rajkumar, 2021, Symplocos mohananii sp. nov. (Symplocaceae) from the Western Ghats of Kerala, India, Phytotaxa 480 (2), pp. 195-200 : 196

Symplocos mohananii J.Stephan, R.Akhil & P.W.Fritsch , sp. nov. ( Figures 1 , 2 )

The new species is similar to Symplocos racemosa Roxburgh (1814: 40) but it differs by having glabrous young branchlets, abaxially glabrous leaf midvein, shallowly crenate-serrate leaf margins, 2–3-mm long bracts, two unequal bracteoles, glabrous calyx lobe margin, pubescent calyx tube, two whorls of 9–12 corolla lobes, pubescent style from base to apex, and an absence of crown formation by the persistent fruiting calyx.

Type:— India. Kerala: Thiruvananthapuram, Ponmudi Hills , 900 m a.s.l., [08°44′40.7″N, 73°07′36.4″E], 20 December 2017, J . Stephan & R . Akhil 83860 (holotype TBGT!, isotypes CALI!, MH!) .

Description:— Evergreen tree 4–10 m tall and 80–120 cm dbh; bark rough, gray; young branchlets light green, glabrous. Leaves alternate, evenly distributed along branchlet, petiolate; petiole green, adaxially grooved slightly toward base, 10–15 mm long, glabrous; lamina purple to brown when young, green when mature, ovate to lanceolate, 6–12 × 3–5 cm, base cuneate, margin shallowly crenate-serrate, apex acuminate with acumen 5–13 mm long, glabrous on both surfaces including midvein, midvein prominent abaxially, impressed adaxially, secondary veins 8–10 pairs. Inflorescences axillary, racemose, not forming a cone in bud, with 12–20 flowers, 4–7 cm long; peduncle and rachis pubescent. Bract single, caducous, green, ovate, convex, 2–3 × 1.0– 1.3 mm, margin denticulate, apex acute, densely pubescent near and on margin abaxially. Flowers bisexual. Pedicels terete, 3–5 mm long, pubescent; bracteoles caducous, 2, green, unequal in size, ovate, convex, 0.7–1.2 × 0.6–0.8 mm, densely pubescent over entire surface with white hairs. Calyx green medially and white marginally, 2–3 × 1.1–1.4 mm; tube green, 2.0– 2.5 mm long, pubescent; calyx limb green, 0.5–0.7 mm, glabrous; lobes 5, unequal, orbicular, 2–3 × 1.1–1.4 mm, thin, margin entire, apex rounded, pubescent medially, glabrous along margins. Corolla white, outer whorl ellipsoid, inner whorl obovoid, convex, glabrous; lobes 9–12 in 2 whorls, 5 in outer whorl, 4–7 in inner whorl, elliptic-lanceolate, those of outer whorl 4.4–5.2 × 0.1–0.2 mm, those of inner whorl 4.3–4.9 × 0.1–0.2 mm, margin entire, apex rounded. Stamens 60–80, connate towards base, loosely pentadelphous in several irregular series, uppermost series longer than corolla; filaments white, 2.0– 5.4 mm long, glabrous; anthers yellow, dorsifixed, ca. 0.3 mm long. Disk pentagonal, pubescent. Ovary 3- locular; ovules 1 or 2 per locule. Style abruptly widening distally, shorter than outer whorl of corolla, 4.2–4.8 mm long, pubescent throughout but more densely so proximally; stigma yellow or black, pulvinate. Fruit brownish green when young, bluish at maturity, ovoid, 1.0– 1.5 cm long, smooth; calyx lobes persistent in fruit, incurved and covering disk, lobes longer than disk but not forming a crown. Mesocarp 1–3 mm thick. Endocarp 3-celled but effectively 1-celled by the collapse of the other 2, ellipsoid but slightly narrowing distally, 0.9–1.2 × 4–5 mm, wall brown, rough, with 3 or 4 deep grooves. Seed 1, yellow, straight.

Phenology:— Flowering November to March; fruiting March to May.

Distribution, habitat and phenology:— Symplocos mohananii grows at the edges of hill top evergreen forest which is separated by grassland, from 900 to 950 m a.s.l. Only a single population of this species is known.

Etymology:— The specific epithet honors Dr. Narayanan Nair Mohanan, the Retd. Senior Principal Scientist, Jawaharlal Nehru Tropical Botanical Garden, Palode and also the mentor and guide of the first author, for his 37 years of outstanding contributions to the field of plant taxonomy.

Conservation status:— Symplocos mohananii is known only from the type locality. Only five larger trees were found on the crest of the Ponmudi Hills. The species is found only at the edge of forest and grassland and it is not found in the deep ravines. The area of occupancy for the species is <10 km 2 and the number of individuals is <10. The total number of mature trees observed was only seven in this particular location. Because this area is part of a major tourist attraction and the edge trees of the trekking path have been cleared, we recommend that this species be classified as Critically Endangered (CR: B2ab; IUCN Standards and Petitions Subcommittee 2019).

Additional specimens examined (paratypes):— INDIA. Kerala: Thiruvananthapuram, Ponmudi hill top, 900‒ 950 m, 08°44′40.7″N, 73°07′36.4″E, 14 February 2018, J . Stephan & R . Akhil JNTBGRI 87305 ( TBGT!); ibid., 24 March 2019, J . Stephan JNTBGRI 87312 ( TBGT!); ibid., 1 February 2020, J . Stephan & N . Mohanan JNTBGRI 94060 ( TBGT!) .

Figures

FIGURE 1. A. Flowering branchlet. B. Trunk and branching pattern of the tree. C. Young leaf, abaxial view. D. Inflorescence in bud, lateral view. E–H. Different stages of flower, lateral view: young bud (E), older bud (F), L/S of flower just opening (G) and apical view at anthesis (H). I. Corolla, dorsal view. J. Bract, abaxial view. K. Two bracteoles from one flower, abaxial view. L. Corolla lobes, abaxial view. M. Calyx limb separated from hypanthium, abaxial view. N. Corolla and stamens, apical view. O. Stamens, ventral view. P–Q. Calyx and gynoecium, lateral view, with calyx intact (P) and removed (Q). R. Calyx limb and disk, apical view. S–T. Young (S) and mature (T) fruit, lateral view. U. L/S of fruit. V. C/S of fruit. W. Endocarp, lateral view. X. Seed, lateral view. (All photographs by J. Stephan)

FIGURE 2.A. Flowering branchlet. B. Mature leaf, abaxial view. C. Young bud, lateral view. D. Older bud, lateral view. E. Bract, abaxial view. F. Two bracteoles, abaxial view. G. Calyx limb separated from hypanthium, abaxial view. H. Two corolla lobes removed from corolla, abaxial view. I. Part of corolla and androecium, adaxial view. J. Calyx and gynoecium, lateral view. K. Fruit, lateral view. L. C/S of fruit. M. Endocarp, lateral view. N. Seed, lateral view. (Illustrations A–B by R. Akhil, C–N by J. Stephan. Drawn from the holotype)