Caryota rumphiana

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Figure 1. C. rumphiana in habitat, Lae, PNG.

Contents

Distribution:

Restricted to subequatorial monsoonal north-eastern Cape York Peninsula from Cape York south to the MacIllwraith Range, usually east of the Great Divide and at altitudes below 600m.

The only indigenous Australian Caryota species is not endemic but has a wide distribution through parts of Malesia and Melanesia - C. rumphiana Becc., the Australian population of which is refered to var australasica Becc.


Ecology:

Commonly in lowland rainforest of varying soil types, i.e. sandy, basaltic, granitic and alluvial, on a range of aspects from flat to steep slopes. Also in semi-deciduous vine forests, broad-leaved swamp forests and brackish or fresh mangroves, contrary to previously published accounts(3). The present sp. occurs as infrequent to frequent scattered individuals or small to large groups, apparently never forming stands. It is particularly abundant in the Bamaga and Iron Range areas where it is a common but not dominant member of the rainforest communities. Pollination is by insect, seed dispersal by flood, birds or mammals.


Description:

A solitary stemmed tree to 15m. with the mode at around 10-12m, leaves bipinnate, to 7m long but usually 3-5m. Flowers on apical and axillary bracteate inflorescences with a rachis bearing many simple rachillae to 2m long. Flowers unisexual, dimorphic in triads of two staminate (male) and one pistillate (female) flowers. Fruits when ripe globose, reddish pink, 2-3.5c m diam. with one to three smooth black seeds.

Habitat:

In rainforest this species attains its maximum development, being smaller in all respects in vine forests (dry) or swampforests (wet) and is part of a typical association, mainly with:Ptychosperma macarthurii, P. elegans, Calamus aruensis (Bamaga area), C. australis, C. caryotoides, C. hollrungii and C. warburgii (Iron Range area), Pandanus zea, Ficus nodosa, Maniltoa lenticelata, Buchanania arborescens, etc. etc. In the vine forests it is associated with Ptychosperma elegans, Calamus australis, C. caryotoides, Pandanus conicus, P. oblatus, Aleurites moluccensis, Bombax ceiba, Adenanthera pavonina, Ficus celbipila etc. etc. In swampforest it forms part of a unique (for Australia) monocot-dominated community including the palms Gulubia costata, Hydriastele wendlandiana, Ptychosperma macarthurii, Licuala ramsayi, Livistona benthamii, Calamus aruensis (Bamaga), C. australis, C. caryotoides, C. hollrungii and C. warburgii (Iron Range) with the Pandans Pandanus zea, P. lanterbachii, P. conicus, Freycinetia marginata, F. percostata and the sedge Mapania macrocephala, gingers of Achasma australasica, Hornstedtia scottiana and Amommum dallachyi, sometimes with the dramatic fern Angiopteris evecta. In the brackish and fresh mangroves associate spp. are the palms Nypa fruticans, Ptychosperma macarthurii, Livistona benthamii and Calamus caryotoides, trees of various mangrove spp. and emergent Melaleuca spp.

Ethnobotany:

While various spp. of Caryota are utilized in other countries for their trunk reserves of starch(4) which attains its maximum prior to flowering, this starch being expressed as sago, apparently no such technologies existed in Australia. It is however sometimes planted as an ornamental. In the Iron Range area it is known as "Kulandoi" while the Gudang people at lived in the vicinity of Cape York called it "Damaraba".

Taxonomic Status:

C. rumphiana is a widespread sp. in parts of Indonesia and New Guinea to the Solomons. Without having New Guinean material for comparison but having seen photographs of var. papuana Becc. it seems possible that the populations each side of Torres Strait are not distinctly different. Future research into this sp. will probably reduce the number of trinomials.

It should be mentioned that a large percentage of the Cape York Peninsula flora is actually Papuan and of recent establishment. C. rumphiana var. australiasica performs exceedingly well under cultivation in the tropics and is one of the fastest growing palms I have ever tried. One can expect the seed to germinate within two months of sowing and the seedlings can be planted out in one year by which time they are about 1. 5 - 2m tall and have bipinnate leaves.

The tree also grows rapidly, which is unfortunate as it dies after flowering, a process which lasts for two years and begins in 6-8 years after planting out, probably less in the wild. However in subtropical areas the plants should be somewhat slower in all respects.

Light shade is desirable for juveniles but adults can take full sun. Unfortunately the leaves are easily damaged by wind so a sheltered site is preferable. The plant is more attractive than C. urens, having flatter, broader leaves with more regularly inserted leaf rachillae. Good soil nutrition and regular watering are needed to prevent the leaves from becoming yellowish in full sun situations. The leaves, although larger than C. mitis present no problem with disposal, likewise the trunk which is less bulby than C. urens. As I know of a specimen of C. rumphiana (from Iron Range) that is thriving in Atherton, a rather cold place, I feel it should accommodate itself easily to southern Queensland.

Caryota rumphiana2-01.jpg
Caryota rumphiana3-01.jpg

Figure 1. Seed collector climbing tree (he is actually there) Figure 2. Seed collector cutting infructescence. (Click image for larger version.)

Figure 3. Success
(he is actually there)
Caryota rumphianaB02.jpg
Figure 3. Success


References:

1. In the heading and subsequent text I attribute the species to Odoardo Beccar; (1843--7920), however the author is sometimes cited as Mart. (Karl Friedrich Philipp von Marflus). The specific epiphet is sometimes (incorrectly) spelled rumfiana.

2. Caryotoid is a Group without taxonomic rank but more or less equivalent to subamily see Ed Moore, Jr. The Major Groups of Palms and their Distribution (reprinted and repaged from Trentes Herbarum 11(2): 27-141 1973) for this classification system.

3. Cavacevich. J. M and Jeanette Cavacevich. Principes. 22(3), 1978. pp. 88-93. In this paper C. rumphiana is stated to be confined to riverine closed forests which is incorrect.

4. Ruddle, Kenneth et al, Palm sago - A tropical starch from Marginal Lands, A.N.U. Press and The University Press of Hawaii.

Contributed by:

Robert Tucker (Text - from Palms & Cycads No. 1, Feb 1984).
Rolf Kyburz,
(Figure 1)

External Links:

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