PNGTreesKey – Neonauclea acuminata Ridsdale


Barry Conn (NSW) & Kipiro Damas (LAE).
Guide to trees of Papua New Guinea
Copyright held by the authors, National Herbarium of New South Wales, and Papua New Guinea National Herbarium

Neonauclea acuminata Ridsdale

Gardens' Bulletin, Singapore Vol. 15: 279 (1970)

Other Literature: C.E. Ridsdale, Blumea 234-235 (1989) Fig. 11-(map; plate)-24.

Family: Rubiaceae

Timber Group: Commercial hardwood

Field Characters: Small sub-canopy tree or Large canopy tree (up to 35 m high); Bole cylindrical (up to c. 50 cm diam.); straight (bole 15-20 m long); buttresses buttresses absent; spines spines absent; aerial roots aerial roots absent; stilt roots stilt roots absent; Bark grey or brown, rough, fissured (thinly to coarsely), slightly scaly or flaky, or rarely pustular, slightly lenticels irregular; Subrhytidome (under-bark) yellow, yellowish brown, orange, or green; less than 25 mm thick, 16.0-20.0; bark blaze consisting of one layer; faintly to non-aromatic; outer blaze yellow (pale (straw-coloured) or white, markings absent, fibrous; inner blaze yellow (pale (straw-coloured) or white, markings absent, fibrous; bark exudate (sap) absent; terminal buds enclosed by leaves.

Indumentum: Complex hairs absent; stinging hairs absent; mature twig indumentum (hairs) absent.

Leaves: Leaves spaced along branches, opposite (in pairs, opposite one another on the branchlet), simple (a leaf composed of a single blade); petiole present, not winged, attached to base of leaf blade, not swollen; leaves broadest at or near middle or rarely broadest above middle, (10.0-) 20.0-36.0 cm, (5.0-) 12.0-20.0 (-22.0) cm; symmetric, entire, not dissected or lobed, acuminate (shortly) or sub acute, venation pinnate, secondary veins open, prominent, intramarginal veins absent; leaves lower surface green, upper surface dark green (glossy), indumentum (hairs) absent; absent; domatia absent; stipules present, joined, joined across twigs, not encircling the twig, leafy, not fringed, large (12-28 mm long), not persistent.

Flowers: Inflorescence axillary, flowers arising from a single point, cones absent; flowers bisexual, not stalked or stalked (shortly (subsessile), flowers with many planes of symmetry, 11.0-16.0 mm long, diameter small (up to10 mm diam.) (5-6 mm diam.); perianth present, with distinct sepals and petals whorls, inner perianth cream-coloured or white; 5, some or partly joined; stamens 5, present (short), free of each other, joined to the perianth (exserted beyond corolla); ovary inferior, carpels joined (when more than one), locules 2; styles solitary, 1.

Fruits: Infrutescence arising from single point (forming a globular fruiting head 8-12 mm diam.), fruit 3.0-5.0 mm long, 2.0 (c.) mm diam., pale brown, not spiny, non-fleshy, multiple, dehiscent (each fruitlet), capsule (each fruitlet spilting into 4 valves); seeds 1 (per fruitlet; many per globular fruiting head), to about 5 mm long, winged (shortly at both ends), narrow (longer than wide) (somewhat bilaterally flattened), seed 1-10 mm diam. (c. 2 mm diam.).

Distribution: West Sepik, Madang, Morobe, Western Highlands, Eastern Highlands, Central & Papuan Islands.

Neonauclea acuminata
Botanical records
in PNGplants database

Map details