Gronophyllum (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Gronophyllum R. Scheffer

Protologue: Ann. Jard. Bot. Buitenzorg 1: 135 (1876).

Family: Palmae

Chromosome number: x= unknown; 2n= unknown

Vernacular names

• Indonesia: nibung merah kecil, pingang salea, pinang utan buwah kecil (Ambon).

Origin and geographic distribution

Gronophyllum comprises about 25 species distributed from Sulawesi, the Moluccas and New Guinea to the Bismarck Archipelago and northern Australia. New Guinea harbours most of the species. The wood of only a single species, G. microcarpum R. Scheffer from the Moluccas, has been reported to be used, but it is likely that various other, very similar species (e.g. G. brassii Burrett, G. sarasinorum Burrett) or other large palms like G. chaunostachys (Burrett) H.E. Moore and G. ledermannianum (Becc.) H.E. Moore are used for the same purpose.

Uses

The bole is scraped and used for roofing in local house construction in the Moluccas and New Guinea.

The young leaf buds are edible and used as a vegetable. The small fruits can be used for chewing with "betel pepper" ( Piper betle L.) leaf and as a substitute for "betel nut" ( Areca catechu L.). The edible starch from the trunk is used as an emergency food and an edible sap is tapped from the inflorescence stalk. The leaf-sheath fibres are used for thatching.

Production and international trade

Utilization of the wood of G. microcarpum is apparently very limited and on a local scale only.

Properties

The wood is pale pink and hard. Traditionally, the smoke inside houses makes the wood very durable and hard.

Botany

A monoecious, pleonanthic, unarmed, single-stemmed or clustered, small to large palm, up to 30 m tall; poles straight, up to 15(-30) cm in diameter. Leaves pinnate, sheaths with a crown-shaft, leaflets few to many, linear-lanceolate to cuneate, apically acute, bifid or ragged truncate. Inflorescence borne below the leaves, solitary at each node, branching to 1-3 orders or rarely spicate, protandrous, with a prophyll and about equally large peduncular bract, rachis bearing whorled or decussate triads of flowers. Flowers unisexual, with 3 sepals and 3 petals, all free. Male flowers asymmetrical to a greater or lesser degree, with 6-9 stamens. Female flowers smaller than the male ones; ovary unilocular with a single ovule, stigmas 3. Fruit a drupe, smooth, with a thin epicarp, red to purplish black when mature. Seed laterally attached, with ruminate or homogeneous endosperm. Seedling with adjacent-ligular germination; eophyll bifid.

The staminate flowers reach anthesis soon after bract fall and are shed after 1 day. The next day the female flowers reach anthesis.

Gronophyllum is botanically poorly known and is in need of taxonomic revision. The formerly recognized genera Leptophoenix and Nengella are now included in Gronophyllum .

Ecology

Gronophyllum species are found in a wide range of habitats, from lowland rain forest to montane mossy forest up to 2000 m altitude. They occur as elements of the understorey or canopy layer, scattered in almost pure stands, and on various soil types including limestone and ultrabasic soils.

Silviculture G. microcarpum can be propagated from seed which remains viable for only 2-3 weeks.

Genetic resources and breeding

As Gronophyllum is botanically poorly known, it is not possible to assess the degree of threat with certainty, but the generally restricted areas of distribution of the now recognized taxa suggest a fair risk of genetic erosion.

Prospects

The wood of Gronophyllum is rarely used and there seems no scope for increased utilization.

Literature

165, 166, 236, 326, 430, 436, 797, 1110.

E. Boer & M.S.M. Sosef