Raphia farinifera (2)

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Figure 1. R. farinifera at The Lagoon, Townsville Palmetum.

One of the three specimens of the giant palm Raphia farinifera, growing by the Lagoon, in The Palmetum Townsville, Australia, started to flower in October 1993. This was unexpected, as the palm was only planted in the ground in 1988, with its age (from germination) estimated to be only 7-9 years. Usually, Raphia species flower at 20-30 years of age.

Raphia is a genus in which the species have a flowering habit which is termed either monocarpic or hapaxanthic, depending on whether the species is single stemmed or clumping. Monocarpy (mono - once or single; carp - fruit bearing) is the process in which a single-stemmed plant flowers and fruits only once following an extended period of strictly vegetative growth, and then dies immediately once the fruit has matured, whereby Hapaxanthy is the process in which a multi-stemmed, clump forming plant flowers and fruits on an individual stem only once then dies. Unlike monocarpy which results in the death of the plant, hapaxanthy means the death of only the flowering/fruiting shoot - other stems will eventually grow to replace the dead ones so that the plant will continue to live.

Figure 2. R. farinifera infructescence

These processes involve many years of vegetative (leaf growth, an abrupt cessation of vegetative growth and then the production of flowering/fruiting structures which may then take a further few years to develop and mature. Immediately prior to the time that the inflorescence begins to emerge, leaves cease to be produced and those already on the plant begin to deteriorate. By the time the fruit is fully mature the trunks are virtually leafless. Fruits mature and fall over a short period, and the palm will eventually topple or be blown over, creating a large untidy pile of decaying leaves, trunk and infructescence. In Raphia the inflorescences are produced from the top of the trunk. Some species have an erect towering structure many metres tall whilst others have pendulous structures which resemble large ropes hanging from the top of the trunk, almost touching the ground, as seen in the accompanying photo of Raphia farinfera. Many hundreds of thousands of flowers are produced, followed by tens of thousands of fruit. Structurally and floristically, the inflorescences are unique within the palm family. Both male and female flowers occur on the same rachilla, the females occupying the basal half, whilst the males the distal half. Flowers are strongly dimorphic; the male flowers are conspicuous, large and tubular with long petals, while the females are inconspicuous and small, the stigma protruding only marginally from between large bracts. The flowering of Raphia farinifera in The Palmetum will give both botanic garden's staff and visitors a unique opportunity to witness one of the palm family's most unusual and dramatic reproductive events.

Contributed by:

John Dowe
(from Palms & Cycads No 40 Oct - Dec 1993).

External Links:

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