Psydrax cudalorensis Soosairaj, 2022

Lincy, Joseph, Soosairaj, Sebastin, Dhivya, Rajappa & Arulanandam, John Peter, 2022, A new species of Psydrax (Rubiaceae: Vanguerieae) from Tamil Nadu, India, Phytotaxa 533 (4), pp. 223-229 : 224-226

Psydrax cudalorensis Soosairaj sp. nov. ( Fig. 1 )

Type:— INDIA. Tamil Nadu, Cuddalore district , elevation 50 m, 11°31′58″ N, 79°41′52″ E, 22 Feb. 2019, S . Soosairaj 2543 (holotype RHT 68952, isotype MH!) .

Small evergreen tree, up to 7 m height; branches quadrangular becoming terete, pubescent. Petiole 9–11mm, pubescent, leaf opposite, elliptic-lanceolate, base cuneate, apex acuminate, 7.8–11.5 × 3.5–4.3 cm, pubescent on abaxial side and glabrous on side, lateral veins 4-6 pairs, domatia at the base of lateral nerves on abaxial side, stipules triangular, pubescent, acute to aristate, on one side 3.2 × 2.1 mm, on the other side 6 × 2 mm. Inflorescence compound cyme, clearly branched, bracts copular at the base of pedicel; pedicel 8–10 mm, pubescent. Hypanthium pubescent, 1.5 mm. Calyx glabrous, lobe 5 toothed, ovate, triangular, pubescent, apex acute. Corolla cream white, 4–5 lobes, ovate - lanceolate, apex acute, tube 2.1× 1.9mm, lobe 1.2× 0.8mm, reflexed, pubescent. Stamens 4–5, epipetalous, filament 0.1–0.3mm, glabrous, anther 1.2× 0.6 mm, reflexed, apiculate. Style glabrous, 5.5 mm, stigma bifid, ovate, 1× 1mm. Drupe, globose, pubescent, 3–6 × 4–6 mm. Pyrene 1 or 2, reniform, surface reticulate-foveolate, 4.5–5 x 3 mm.

Etymology:— The specific epithet cudalorensis is given based on the location of collection i.e. Cuddalore district in Tamil Nadu, India.

Phenology:— Flowering occurs in February–March and November, and fruiting from April–May.

Distribution and ecology and conservation status:— Psydrax cudalorensis was found growing in sacred groves of Cuddalore and Pudukkottai districts of Tamil Nadu, India. The forest type of these groves corresponds to Tropical Dry evergreen forest of 8A and 7C1 described by Champion & Seth (1968). P. cudalorensis is associated with Garcinia spicata Hooker f. (1875: 486), Pterospermum suberifolium (L.) Willdenow (1800: 728), Lepisanthes tetraphylla Radlkofer (1878: 276) , Syzygium cumini (L.) Skeels (1912: 25), Mallotus philippensis (Lam.) Müller Argoviensis (1865: 196) and Argyreia cymosa Sweet (1826: 289) . The authors observed more than fifty mature individuals at this locality although the exact population size and its distribution range needs to be explored further.

Additional specimen examined (paratype):— INDIA. Tamil Nadu, Cuddalore district, Naduveerappattu sacred grove, 25 November 2019, Soosairaj 2820 ( RHT!, St. Joseph’s College , Tiruchirappalli) .

Psydrax dicoccos Gaertn. — INDIA, Dindigul district, Ghat road to Kodaikanal (RHT 43798), Psydrax dicoccos Gaertn. — HONG KONG, S. Coll. 429 (K000763714), INDONESIA, Teijsmann, S.N. (K000763704), P. umbellata (Wight) Bridson — INDIA, Wallich, 1328B (K000031526), INDONESIA, Korthals, S.N. (K000763703), P. palma (K.Schum.) Bridson — GABON, In ditione Munda Silange farm, Soyaux (K000422522), P. manensis (Aubrév. & Pellegr.) Bridson — IVORY COAST, Man to Danané, Aubréville, 1099 (K000043454).

Figures

FIGURE 1. Psydrax cudalorensis sp. nov. A. Habit. B. Flower. C. Calyx. D. Corolla split open. E. Anther ventral (left) dorsal (right) views. F. Pistil. G. l.s. and t.s. of ovary. H. Fruit. I. Pyrene. Illustration of Holotype. S. Soosairaj 2543, (drawn by Lincy Joseph).