Finschia chloroxantha (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Finschia chloroxantha Diels

Protologue: Bot. Jahrb. 54: 204 (1916).

Family: Proteaceae

Chromosome number: 2n= unknown

Synonyms

• Grevillea densiflora White (1922).

Vernacular names

• Papua New Guinea and surrounding islands: sauge (Menari), akama (Malaita), togtua (Bougainville), mbrein (Sorong).

Origin and geographic distribution

The tree is endemic in Papua New Guinea and surrounding islands and widely distributed in the Solomon Islands.

Uses

Seeds are locally an important food-nut in coastal regions of Papua New Guinea and surrounding islands, particularly in Bougainville. The species has been introduced in Vanuatu, New Hebrides, where the trees are extensively planted for their seeds. In Sorong (Irian Jaya) they are said to be useful against leprosy. The reddish timber has potential for cabinet making, but the primary use of the trees is as a source of nuts (seeds). The bright golden-yellow racemes are most attractive and the species could possibly be useful as an avenue tree throughout the tropics.

Botany

• Tree up to 30 m tall; trunk buttressed, often with stilt roots; bark grey to light brown, usually marked with longitudinal lines of pustules; shoots and older branches densely clothed with a ferrugineous, or tawny, pubescence.
• Leaves narrow elliptic to narrow-obovate or lanceolate, 9-40 cm x 3.5-13 cm; apex acute or blunt, base cuneate, midrib stout, prominent beneath, nerves 12-30 pairs; petioles slender, semi-terete, up to 2.5 cm long.
• Inflorescences many-flowered racemes, solitary, axillary or ramiflorous, including the short peduncle up to 30 cm long; rachis pubescent, up to 3 mm diameter; bracts very early caducous, subulate or linear, up to 1 mm long.
• Flowers yellow-green to bright golden-yellow, pedicels and perianth segments laxly clothed with brown hairs; perianth segments (4-)6-8(-9) mm; disk prominent; ovary glabrous, up to 2 mm long; style narrowly clavate, up to 1.5 cm long; stigma terminal, short-conical.
• Fruit a subglobose, green-yellow drupe, 2.5-5.5 cm x 2-5 cm, borne on a stout stipe.

Flowering is from December to March, fruiting from March to August.

Based on the dimensions of the fruit two varieties are distinguished: var. chloroxantha with fruits 2.5-3 cm x 2-2.5 cm and var. macrocarpa Sleumer with fruits 5-5.5 cm x 5 cm. Finschia ferruginiflora White occurs in the central highlands of New Guinea; its seeds are also boiled and eaten.

Ecology

F. chloroxantha occurs scattered in primary and secondary forests, and drier areas in swamp forest, at altitudes up to 1800 m.

Agronomy

Propagation from seed is usual, but the seeds often germinate slowly. The fruit is harvested when ripe and roasted to crack the shell to obtain the edible kernel.

Prospects

The tree has considerable potential, both as an ornamental and a nut crop, the latter possibly in competition with the macadamia nut (Macadamia integrifolia Maiden & Betche) from the same family.

Literature

• Sleumer, H., 1955. Proteaceae. In: van Steenis, C.G.G.J. (Editor): Flora Malesiana, Series 1. Vol. 5. pp. 162-164.

Authors

R.J. Johns