Syzygium whitmorei Craven & Damas, 2021

Craven, L. A., Damas, K. Q. & Cowley, K. J., 2021, Studies in Papuasian Syzygium (Myrtaceae): 2. The furfuraceous species of subg. Syzygium, Blumea 66 (1), pp. 57-81 : 80

40. Syzygium whitmorei Craven & Damas , sp. nov. — Fig. 2 : 4.4; Map 9

From Syzygium buettnerianum (K.Schum.) Nied. it differs in having the leaf lamina narrowly elliptic,ovate or obovate with the acumen flat (elliptic, ovate, narrowly elliptic,or narrowly ovate with the acumen recurved in S. buettnerianum ); the hypanthium obconic,stipitate obconic,or narrowly obconic (goblet-shaped to rarely elongated goblet-shaped in S. buettnerianum ); and c. 50 stamens (c. 30‒35 in S. buettnerianum ). — Type: BSIP (Whitmore’s collectors) 3104 (holo L!), Solomon Islands, NW New Georgia Island, Vaimbu River, well drained primary forest on hillside, alt. c. 160 m, 19 Mar. 1964.

Etymology. The species is named in honour of Timothy Charles Whitmore (1935‒2002) who,as a forest botanist in the forestry department of the then British Solomon Islands Protectorate, established an extensive collection program between September 1962 and September 1964.

Tree to 36 m tall; outer bark dark brown, flaky and papery. Vegetative branchlet terete, rounded, 3‒6 mm diam; bark dull, smooth, slightly or very striate, or cracked and furfuraceous, not glandular-verrucose, flaking in relatively large pieces or sometimes peeling. Leaf lamina narrowly elliptic, ovate or obovate, 7.2‒12.8 by 1.5‒5.4 cm, 2.3‒3.7 times as long as wide; base cuneate; apex long acuminate; acumen flat; margin flat; coriaceous; primary and secondary venation distinctly different with secondaries relatively little developed and not or rarely joining the intramarginal vein; primary veins 25‒50 on each side of the midrib, in median part of lamina at a divergence angle of 60‒70° and 1‒2 mm apart; intramarginal vein present, weakly arched, 0.5‒2 mm from margin, secondary intramarginal vein present. Petiole 5‒12 mm long. Reproductive seasonal growth unit with distinct vegetative and reproductive zones. Inflorescence leafy, terminal or distal axillary, paniculate-corymbose, up to 20 by 8 cm, major axis c. 3 mm thick at the midpoint, bark furfuraceous or not; bracts caducous; bracteoles subtending each flower, caducous. Flower buds with the apex rounded to obtuse. Flowers white or cream. Hypanthium glossy, striate, visibly gland-dotted, sometimes angled laterally (i.e., 2-costate) and then stipitate; stipitate or not; obconic, stipitate obconic, or narrowly obconic, 3‒4 by c. 2 mm, stipe up to 1 mm long. Calyx reduced to a rim of tissue 0.1‒0.2 mm long. Petals 4, calyptrate (coherent and falling as a cap). Staminal disc raised ( Fig. 2 : 4.4). Stamens c. 50, 3.5‒9 mm long. Style 6.5‒7.5 mm long. Placentation axile-median; placenta a subelliptic flattened cushion. Ovules c. 8‒10 per locule, spreading, arranged irregularly. Mature fruit reddish purple, smooth or wrinkled, subspheroid to depressed spheroid, 8‒12 by 12‒16 mm excluding the calyx; with the hypanthium rim not appreciably expanding in fruit and 2‒2.5 mm diam; seed depressed spheroid, c. 12 mm across, cotyledons collateral.

Distribution — Solomon Islands.

Habitat & Ecology — Well-drained primary forest on ridge top or hillside, secondary forest on ridge top, disturbed high forest, dense forest. Altitude 30‒520 m.

Note — The inflorescence is a leafy panicle-corymb, in form intermediate between a panicle and a corymb, with leaves on the proximal part of the reproductive seasonal growth unit and the panicle-corymb proper in a terminal position. Additional inflorescences may also occur in distal leaf axils of the growth unit. The calyx of S. whitmorei is reduced to a rim of tissue with discernible lobes not evident as it is in several other furfuraceous species. Non-furfuraceous plants sometimes occur sporadically through the Solomons’ archipelago, e.g., BSIP 1489, 9857. These interesting cases otherwise agree with the furfuraceous specimens placed in this species.

Acknowledgements Studies of Papuasian Syzygium at CANB were commenced by Tom Hartley and Lyn Craven in the 1970s. It is a matter of regret that these studies could not be pursued to fruition at that time; two papers only being produced.Tom’s enthusiasm for the genus and his excellent field knowledge considerably assisted the project in refining species concepts for Papuasian Syzygium ; these have been further refined in recent years by Lyn as the work has progressed. Kipiro Damas’ input into the delimitation of species treated in the present paper has further improved our knowledge of the species of sect. Furfuraceum . A grant to Lyn from The Hermon Slade Foundation for research into Syzygium enabled him in 2006 to visit PNG and there collaborate with Kipiro, and enabled Kipiro to visit Canberra in 2011 and work with Craven on sect. Furfuraceum . Cath Busby obtained geocode data for those collections for which the data had not been recorded in Lyn’s specimen database.Cath also read the descriptions.Nunzio Knerr generated the distribution maps ready for final editing. Siobhan Duffy, in good humour, printed in A3 format the numerous digital images of type specimens that were sent by herbaria for Craven to study,prepared the staminal disc figures from Craven’s crude drawings, prepared the final versions of the distribution maps,and prepared the SEM plate.Mark Talbot, Microscopy Centre,CSIRO Plant Industry, produced the scanning electron micrographs in Fig. 1 , and Siobhan Duffy produced the final plate, and Nunzio Knerr helped edit this plate for publication. The curators and/or directors of the following herbaria have made available specimens and/or images that have been used in the ongoing studies of Papuasian Syzygium and they are sincerely thanked for this assistance: A, B, BISH, BM, BO, BRI, CANB, E, K, L, LAE, LY, MEL, NY, P, WRSL. Those who have assisted Lyn variously in the foregoing and other matters include, in no particular sequence: Emily Wood, Melinda Peters, Wayne Takeuchi, Eve Lucas, Ana Claudia Araujo, Shelley James, Frédéric Danet, Gaëtan Guignard, Mélanie Thiébaut, Robin Hide, Jan-Frits Veldkamp, Wim Vink, Gerard Thijsse, Nicolien Sol, Thomas Zanoni, Rusty Russell, Anton Igersheim, Adele Smith.

Figures

Fig. 2 Staminal disc types in Syzygium species. Series 1: Flat; series 2: descending; series 3: ascending; series 4: raised.

Fig. 1 Scanning Electron Micrographs:Furfuraceous inflorescence branch- lets in Syzygium. a–c. Syzygium furfuraceum Merr.& L.M.Perry: a. Branchlet showing strongly furfuraceous surface;b.close-up of epidermal layer:1. outer epidermal flake; 2. spongy epidermal tissue; c. detail of epidermal layer: 1. outer epidermal flake; 2. spongy epidermal tissue. — d–e. Syzygium branderhorstii Lauterb. d. Branchlet showing weakly furfuraceous surface; e. close-up of epidermal layer (a–c: Takeuchi, Siga & Towati 14944; d–e: NGF (Vandenberg & Mann) 42251, all CANB). — Scale bars: a, d = 1 mm; b, e = 100 μm; c = 10 μm. — Photos by Mark Talbot.