Garcinia gamblei P.S. Shameer, T. Sabu & N. Mohanan, 2017

Shameer, Peerumuhammed Subaida, Sabu, Thyagarajan & Mohanan, Narayanan Nair, 2017, Garcinia gamblei (Clusiaceae), a new species from the southern Western Ghats, India, Phytotaxa 297 (1), pp. 71-76 : 71-72

Garcinia gamblei P.S. Shameer, T. Sabu & N. Mohanan , sp. nov. ( Figs. 1 & 2 )

Garcinia gamblei is allied to G. pushpangadaniana in general habit; tetragonous branchlets; milky exudation; arrangement of male flowers in axillary fascicles; arrangement of stamens in 5-phalanges and shape of stigma lobes; but differ from the latter in having horizontal branches against drooping branches; sessile flowers against pedicelate flowers; arrangement of staminodes in loose bundles or sometimes even free against staminodes always in 5- phalanges; ovary locules and stigma lobes 5 against 6–8 and fruits vertically grooved with depressed apex against non grooved and warty with mammillae apex.

Type: — India. Kerala: Thiruvananthapuram Dist., Ponmudi, 080 46’ 11.1’’ N, 0770 06’ 32.6’’E, 1031 m alt., 18 May 2016 (with immature fruit), P.S. Shameer 86601 (holotype TBGT!, isotype MH!, CAL!).

Dioecious, evergreen medium sized trees up to 15 m high; bark grayish white with white mottle, old ones flaked; exudation milky; crown pyramidal with horizontal spreading branches; branchlets tetrangular. Leaves opposite, coriaceous, glabrous; lamina usually ovate or broadly elliptic, 20–28× 10–12 cm, obtuse–cuneate at base, acute at apex, margin sub revolute; midribs raised on both sides, secondary veins conspicuous, ca. 25–40 pairs, raised on both surfaces; petioles 1–1.5 cm long, stout, transversely rugose and with longitudinal ridges, pale greenish, adaxially ligulate at the base. Male flowers 3–15, sessile, fascicled, axillary or on axils of fallen leaves. Sepals 5, free, ca. 5× 3 mm (unequal), imbricate, orbicular, convex; margin membraneous and ciliate. Petals 5, free, ca. 8× 6 mm, imbricate, pale greenish, obovate; margin membraneous, glabrous. Stamen 5-phalangiate, glabrous; phalanges antipetalus, alternating with 5 intra staminal discs; stamens 7–17 in each phalanges, filament ca. 0.5 mm long, anther lobes brown; rudimentary pistil absent. Female flowers usually solitary, rarely 2–4 in fascicles, axillary or on axills of fallen leaves, sub-sessile (pedicel below 5 mm long). Sepals 5, free, unequal, inner ones ca. 6× 5 mm, outer ca. 3× 2 mm, imbricate, orbicular, convex; margin ciliate. Petals 5, free, 0.9–1× 0.8 cm, imbricate, orbicular − obovate; margin membraneous. Staminodes in loose bundles, filaments free or 2–3-united. Ovary globose, ca. 5 mm diam., 5-locular; style sessile; stigma 5-lobed, peltafid. Fruits berry, ca. 8× 7 cm, globose, irregularly ridged on surface, depressed on distal end. Seeds1–3, rarely 5, oblong, ca. 2.3× 1.7 cm.

Phenology: —Flowering December–January; Fruiting June–August.

Habitat & Ecology:—Western Ghats: Kerala: Thiruvananthapuram District. Ponmudi hills, in shola forests at 950–1150 m alt. We could locate about 25 plants which included small to medium sized trees. Seedlings were very few in the locality.

Distribution: —Hitherto known only from the type locality Ponmudi Hills of southern Western Ghats of Agasthyamala Biosphere Reserve.

Etymology: —The specific epithet is in honors of J. S. Gamble, pioneer in floristic studies of erstwhile Presidency of Madras.

Additional specimens examined (Paratypes): — INDIA. Kerala: Thiruvananthapuram, Ponmudi , 850 m, 7 March 1980, K. Vivekanandan 66141 (MH!) ; Thiruvananthapuram, Ponmudi , 1100 m, 8 March 1980, M. Mohanan 66618 (MH!) ; Thiruvananthapuram, Ponmudi , 1040 m, 5 November 2015, P. S. Shameer 86602 (TBGT!) ; Thiruvananthapurm, Ponmudi , 1022 m, 14 March 2016, P. S. Shameer 86631 (TBGT!) ; Thiruvananthapuram, Ponmudi , 1005 m, 26 May 2016, P. S. Shameer 86636 (TBGT!) .

Note: —While examining the collections housed at Madras Herbarium (MH) in connection with taxonomic revision of genus Garcinia , the authors could find two specimens viz., K. Vivekanandan 66141 and M. Mohanan 66618, from the type locality of the new taxon (Ponmudi, Thiruvananthapuram), erroneously identified as Garcinia xanthochymus Hook. f. ex Anderson (1874: 269) . In our previous work ( Sabu et al. 2013) we studied these materials and found distinct from G. xanthochymus , which is a species distributed in North East India and Andaman Islands. They were apparently included under G. pushpangadaniana again based on resemblance with latter. Further on close observations of live specimens at Ponmudi, they were proved to have many distinct morphological features, ( Table 1 & Fig. 3 ) enough to be considered as a distinct species, but allied to G. pushpangadaniana .

Figures

FIGURE 1. Garcinia gamblei A. Branch with fruit; B. Male flower; C. Female flower; D. Staminal phalanges; E. Ovary with staminodes; F. Ovary Cross Section; G. Seed. (after P. S. Shameer JNTBGRI 86601).

FIGURE 2. Garcinia gamblei A. Habit; B. Blaze showing exudate (inset); C. Leaves; D. Male flower buds; E. Single male flower; F. Female flower; G. Dissected female flower showing staminodes and intra staminal disc; H. Immature fruits; I. Mature fruit; J. Seeds (Photos: P. S. Shameer).

FIGURE 3. A–F: Garcinia gamblei A. Male inflorescence; B. Female flower; C. Dissected female flower showing staminodes; D. Immature fruit; E. Mature fruit; F.Seed. A1–F1: Garcinia pushpangadaniana A1. Male inflorescence; B1. Female flower; C1. Dissected female flower showing staminodes; D1. Immature fruit; E1. Mature Fruit; F1. Seed. (Photos: P. S. Shameer)