Barry Conn (NSW) & Kipiro Damas (LAE).
Copyright held by the authors, Royal Botanic Gardens and Domain Trust, and Papua New Guinea National Herbarium

Zygogynum calothyrsum (Diels) Vink

Blumea Vol. 31: 53 (1985)

Field Characters: Small trees or large trees. Bole cylindrical; straight; buttresses absent; spines absent; aerial roots absent; stilt roots absent. Bark dark brown, rough, pustular; lenticels elongated vertically; subrhytidome pale yellow cream-coloured or orange; bark thickness <25 mm thick, 3.0 mm thick; blaze consisting of one layer; strongly aromatic; pleasant; outer blaze orange or brown, with stripes, granular with splinters; inner blaze brown or orange, with stripes, granular with splinters; exudate present, colourless, spotty, changing colour on exposure to air, to orange or brown, slightly sticky. Terminal buds not enclosed by leaves; complex hairs absent; stinging hairs absent; mature twig without hairs.

Leaves: Spaced along branches <internodes readily visible>. Leaves spiral, simple; petiole present 2.5 cm long, slightly winged at base of lamina or not winged, attached to base of leaf blade <not peltate>, not swollen; lamina broadest above middle or broadest at or near middle, (12.0-) 20.0-25.0 cm long, (5.5-) 7.5-9.0 cm wide; lamina symmetric slightly winged, margin entire, not dissected or lobed, apex obtuse or emarginate or retuse, venation pinnate <secondary veins arising from the midrib along its length>, secondary veins open <spaced far apart to easily see tertiary veins>, not prominent, but visible, intramarginal veins absent; lower surface pale green or slightly blue-green, upper surface green, hairs absent; oil dots absent; domatia absent; stipules absent.

Flowers: Inflorescence terminal <at branch ends>. Flowers on a branched axis; flowers bisexual, stalked, with many planes of symmetry <actinomorphic>, 12.0-14.0 mm long, large (>10 mm diam.) 15-20 mm diam.; perianth present, with all sepals and/or petals (hence tepals) similar, pale yellow or cream-coloured with dull red tinge on margin; inner perianth 5, free; stamens 100 (dull yellow), filaments present, free of each other, free of perianth; ovary superior <seated above petals and sepals; hypogenous>, carpels joined (when more than one) <syncarpous>, locules 5; styles absent and stigma not persistent.

Fruits: Fruits arranged on branched axis. Fruit 13-15 mm long, 13.0-15.0 mm diam., fruit red deep pink or reddish yellow, not spiny, fleshy, simple, indehiscent, berry.

Distribution: Papuan Islands, Milne Bay, Morobe, East Sepik, West Sepik, Central, Southern Highlands, Western Highlands & Eastern Highlands.

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