Memecylon ponmudianum Sivu, N.S.Pradeep & Pandur., 2014

Memecylon ponmudianum Sivu, N.S.Pradeep & Pandur. View in CoL , sp. nov. ( Figs. 1 View FIGURE 1 & 2 View FIGURE 2 )

Memecyli terminali et M. subramanii similis , a priore foliis maioribus sessilibus, basi cordatis amplexicaulibus, inflorescentia robusta breviter pedunculata, pedicellis calycibus campanulatis distincte brevioribus, a posteriore caule ramulisque teretis, foliis minoribus subsessilibus amplexicaulibus, umbellis terminalibus breviter pedunculatis, pedunculo tereto, pedicellis calycibus distincte brevioribus, etc. differt.

Type:— INDIA. Kerala: Thiruvananthapuram district, Ponmudi Hills, Kowdiyarmottai , 8°43′ N, 77°07′ E, ± 779 m, 30 December 2009 (fl.), Sivu 65150 (holotype TBGT! GoogleMaps , isotype MH! GoogleMaps ).

Large shrubs or small trees; ± 4 m tall; young branchlets terete, glabrous, greenish yellow when dry; bark thick, greyish brown, deeply fissured, peeling off, internodes 3–3.5 cm long. Leaves opposite, 8–12 × 4–6 cm, oblonglanceolate or ovate, subcordate or cordate and amplexicaul at base, acuminate at apex, obtuse at the very apex, margin entire, coriaceous, glabrous, yellowish-green when dry; lateral veins 12–15 pairs, conspicuous, raised below with conspicuous, looping intra-marginal veins; foliar sclereids filiform, elongated and loosely packed; petiole absent. Inflorescence terminal, many-flowered branched umbellate cymes, these ca. 2 cm across; peduncles terete at base and subterete at apex, 1–1.5 cm long, secondary branches 4–5 mm long, brownish green; bracteoles ovate, ca. 1.5 mm long, glabrous, persistent, light green. Flowers ca. 4 mm across, pinkish blue; buds obtusely acute; pedicels 1–1.5 mm long, slender, violet-red; calyx tube campanulate, ca. 2 mm across, glabrous, white suffused with pink, fleshy, deeply - 4 lobed, papillate on outer surface, wavy along margins; disc shallowly striated; petals 4, suborbicular, ca. 2 × 2.5 mm, glabrous, acute or apiculate at apex, pinkish blue; stamens 8, equal, incurved in buds, filaments slender, to 3.5 mm long, glabrous, blue, anthers curved, connective with a gland, ca. 1 mm long, white; ovary unilocular, 6-ovuled, placentation free central; style subulate, ca. 5 mm long, glabrous, pale blue; stigma acute. Berries globose, 5–6 mm across with persistent calyx, yellowish red when young, bluish black when mature; seed 1; embryo with wrinkled cotyledons and long hypocotyl.

Phenology:—Flowering and fruiting occurs during December–April.

Etymology:—The specific epithet ‘ ponmudianum ’ refers to the type locality, the Ponmudi Hills of the Thiruvananthapuram district in Kerala state, India.

Distribution and habitat:— Memecylon ponmudianum grows in evergreen forests at elevations of 750–850 m a.s.l. in Agasthyamalai Biosphere Reserve ( Fig. 3 View FIGURE 3 ). There is only a single population with about 50 mature individuals of large shrubs or small trees and several seedlings of varying age found within an area of about 8 km 2. The associated species include Uniyala multibracteata ( Gamble 1920: 340) Robinson & Skvarla (2009: 153) , Tarenna alpestris ( Wight 1845: t. 1040) Balakrishnan (1982: 175), Eugenia rottleriana Wight & Arnott (1834: 133) , etc.

Relationships:— Memecylon ponmudianum is allied to M. terminale Dalzell (1851: 121) and M. subramanii Henry (1981: 492) , but differs from the former by the larger and sessile leaves with a cordate and amplexicaul base, robust and shortly pedunculate inflorescences, the pedicels distinctly shorter than the campanulate calyx, and it differs from the latter by the terete stem and branchlets, smaller amplexicaul leaves, terminal short-pedunculate umbellate cymes with terete peduncle and the pedicels distinctly shorter than calyx. The diagnostic morphological characters of the new species and the related species are given in Table 1. A View TABLE 1 key to the species with cordate leaf bases occurring in Peninsular India and Sri Lanka is also provided below for comparison.

Additional specimen examined (paratype):— INDIA. Kerala: Thiruvananthapuram district, Ponmudi Hills, Kowdiyarmottai , ± 743 m, 8°41′ N, 77°7′ E, 15 January 2011 (fr.), Sivu 65187 ( TBGT) GoogleMaps .

Population structure and conservation status:— There is only a single population so far reported in elevations of 750–850 m, with about 50 mature individuals in the evergreen forests, occupying in less than 10 sq km area. The number of seedlings estimated were less than 100 individuals and were prone to severe grazing. Since it is known only from a single population with continuing decline of the number of mature individuals due to various parameters like forest fire, grazing, etc., and following the IUCN criteria ( IUCN 2001) for assessing the status of Rare and Threatened plants, M. ponmudianum is considered as Critically Endangered (CR), in the category [B2a, b(v)].