Syzygium idanum 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 : 71

19. Syzygium idanum Craven & Damas , sp. nov. — Fig. 2 : 1.6; Map 6

From Syzygium furfuraceum Merr. & L.M.Perry it differs in having the leaf lamina base attenuate (obtuse in S. furfuraceum ) and 15 or 16 primary veins on each side of the midrib (30‒37 in S. furfuraceum ); and the hypanthium not furfuraceous and with a stipe c. 2 mm long (furfuraceous and up to 0.5 mm long in S. furfuraceum ). — Type: Brass 31320 (holo CANB!; iso L n.v., NY!), Papua New Guinea, Eastern Highlands Province, NE slopes of Mt Michael, in gullies in Nothofagus forest, alt. 2000 m, 3 Sept. 1959.

Etymology. The specific epithet is derived from the Greek, idanos, fair, comely,in reference to the attractive appearance of specimens of this species.

Tree to 20 m tall; bark pale brown or silvery brown, flaky. Vegetative branchlet terete, rounded, 2‒3 mm diam; bark dull-glossy or glossy, smooth; slightly glandular-verrucose, persistent. Leaf lamina obovate, 9‒11.5 by 5‒5.5 cm, 1.8‒2.1 times as long as wide; base attenuate; apex obtuse or rounded, margin revolute; cartilaginous; primary and secondary venation generally similar with all or nearly all secondaries joining the intramarginal vein or distinctly different with secondaries relatively little developed and not or rarely joining the intramarginal vein primary veins 15 or 16 on each side of the midrib, in median part of lamina at a divergence angle of c. 60° and 3‒5 mm apart; intramar- ginal vein present, weakly arched, 1.5‒2 mm from margin, secondary intramarginal vein present. Petiole 6‒8 mm long. Reproductive seasonal growth unit with a reproductive zone only. Inflorescence leafless, on branchlets below the leaves, on branches or cauline, paniculate, up to 14‒17 by 17‒18 cm, major axis 3.5‒4 mm thick at the midpoint, bark furfuraceous; bracts persistent or caducous; bracteoles subtending each flower, caducous. Flower buds with the apex rounded to obtuse. Flowers cream. Hypanthium dull-glossy, striately glandularwrinkled, visibly gland-dotted; stipitate; stipitate-obconic or goblet-shaped 5.5‒6 by 3.75‒4.25 mm, stipe c. 2 mm long. Calyx is a rim of tissue on which 4 lobes usually can be distinguished, lobes c. 0.5 mm long. Petals 4, calyptrate (coherent and falling as a cap). Staminal disc flat ( Fig. 2 : 1.6). Stamens 100‒105, 5.5‒9 mm long. Style c. 6 mm long. Placentation axile-basal; placenta a small cushion. Ovules 18‒20 per locule, ascending, arranged irregularly. Fruit not seen.

Distribution — Papua New Guinea.

Habitat & Ecology — Gullies in Nothofagus -forest, montane forest. Altitude 2000‒2500 m.

Note — The leaf does not have an acumen but the obtuse leaf apex is recurved.

Figures

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