Melicope balgooyi Appelhans, W.L. Wagner & K.R. Wood, 2014

Appelhans, Marc S., Wagner, Warren L. & Wood, Kenneth R., 2014, Melicope balgooyi Appelhans, W. L. Wagner & K. R. Wood, a new species and new record in Melicope section Melicope (Rutaceae) for the Austral Islands, PhytoKeys 39, pp. 77-86 : 78-81

Melicope balgooyi Appelhans, W.L. Wagner & K.R. Wood sp. nov. Figs 3 , 4a

Type.

AUSTRAL ISLANDS: Rapa Iti, Maii, below rim near Pokumaru, 29 Apr 2002, K.R. Wood 9727 (holotype: PTBG-041326!, isotype: NY!).

This new species of Melicope differs from other species in that genus by the combination of alternate to sub-opposite leaves and oblanceolate leaves with a cordate base.

Description.

Shrub 50 to 150 cm of height; plants possibly dioecious; trichomes simple, greyish-white; branches brown-red and glabrous, 2-3 mm wide at third internode. Leaves with glandular dots, alternate to sub-opposite, unifoliolate, glossy dark green above with yellow or green-white midrib, 4.5-9 × 2.3-3.8 cm, petiole 0-1 mm long, terete, glabrous; blades sub-coriaceous, glabrous on both sides, obovate to oblanceolate, margin entire, apex rounded or obtuse, base cordate; venation brochidodromous, midrib prominulous or plane on both surfaces, secondary veins and veinlet reticulation prominulous, 10-17 secondary veins per side. Inflorescences unisexual, axillary, bracteate, several-flowered, up to 1.8 cm long, axes and bracts puberulent. Flowers unisexual, tetramerous; pedicel 1.3 to 2.2 mm long; sepals ovate to rounded, pellucid-dotted, glabrous or slightly ciliolate, 1.2 to 1.5 mm long, same size in staminate and pistillate flowers; petals ovate to elliptic, cream-green, pellucid-dotted, glabrous, 2.5 to 2.8 mm long, same size in staminate and pistillate flowers; stamens 8, glabrous; gynoecium 4-carpellate, glabrous, pellucid-dotted, 2 mm long, stigma peltate, young stigma white. Fruiting carpels and seeds not known.

Additional specimens

(paratypes). Austral Islands. Rapa: Pokumaru summit region, upper windswept slopes of Maii, 21 Apr 2002, K.R. Wood 9698 (PTBG!, NY!).

Distribution and ecology.

Austral Islands (French Polynesia), only known from the type locality on slopes near the summit of Mount Pokumaru on Rapa; 550-580 m.

Melicope balgooyi was discovered around the tall spire-like peak of Pokumaru ( Fig. 4b ) between 550 and 580 m. The habitat is characterized by a windswept shrubland and forest that runs along and below an east to west ridgeline. The plant communities around Pokumaru are unique with small relictual patches of tropical montane cloud forest (TMCF) along with adjacent wet cliffs and steep slopes dominated by Freycinetia arborea Gaudich. Tree species in the TMCF zone which are associated with Melicope balgooyi include Fitchia rapense F. Br., Meryta choristantha Harms, Oparanthus coriaceus (F. Br.) Sherff, Carokia collenettei Riley, Metrosideros collina (J.R. Forst. & G. Forst.) A. Gray, Geniostoma rapense F. Br., and Weinmannia rapensis F. Br. Shrubs, vines, and herbs include Dianella intermedia Endl. var. punctata F. Br., Astelia rapensis Skottsb., Plantago rupicola Pilg., Alyxia stellata (J.R. Forst. & G. Forst.) Roem. & Schult., Freycinetia arborea , and Hebe rapensis (F. Br.) Garnock-Jones. Dominant ferns include Sphaeropteris medullaris (G. Forst.) Bernh., Alsophila stokesii (E.D. Br.) R.M.Tryon, Blechnum attenuatum (Sw.) Mett., Blechnum orientale L., Blechnum venosum Copel., Blechnum vulcanicum (Blume) Kuhn var. rapense E.D. Br., Polystichum rapense E.D. Br., Dicranopteris linearis (Burm. F.) Underw., Belvisia dura (Copel.) Copel., Doodia media R. Br., Elaphoglossum savaiense (Baker) Diels, and Davallia solida (G. Forst.) Sw. Less than 20 individuals of Melicope balgooyi are estimated to occur around this only known site.

Etymology.

The species is named in honor of Dr. Max M.J. van Balgooy, a specialist of the SE Asian flora. Dr. van Balgooy has annotated the herbarium sheets of this new species stating that it is an "unusual Rutaceae near Platydesma ". Phylogenetic studies ( Harbaugh et al. 2009; Appelhans et al. 2014a, 2014b) have shown that Platydesma is included within Melicope , proving Dr. van Balgooy’s assumptions to be true. In addition to Melicope maxii T.G. Hartley, which is endemic to Sulawesi (Indonesia), Melicope balgooyi is the second species of Melicope named after Dr. van Balgooy.

Figures

Figure 3. The newly described Melicope balgooyi Appelhans, W. L. Wagner & K. R. Wood. A Flowering branch B Leaf with detailed venation C Pistillate inflorescence [peduncle not shown in full length] D Single staminate flower. Based on K. R. Wood 9727 (PTBG, A-C) and K. R. Wood 9698 (PTBG, D).

Figure 4. A Habit of Melicope balgooyi Appelhans, W. L. Wagner & K. R. Wood in situ B Habitat of Melicope balgooyi around the steep precipitous slopes of Pokumaru, Rapa, Austral Islands.