Balaka macrocarpa
| Balaka (bah-LAHK-ah) macrocarpa (mak-roh-KAR-pah) | |||||||
|---|---|---|---|---|---|---|---|
 Fiji. Photo-naturefiji.org | |||||||
| Scientific Classification | |||||||
| |||||||
| Synonyms | |||||||
|
| |||||||
| Native Continent | |||||||
 | |||||||
| Morphology | |||||||
| |||||||
| Culture | |||||||
|
| |||||||
| Survivability index | |||||||
|
| |||||||
| Common names | |||||||
|
| |||||||
Contents
Habitat and Distribution
Balaka macrocarpa is restricted to Vanua Levu, Fiji, in the center of the island near Mt. Sorolevu and on Natewa Peninsula, where it is a locally common understory palm in wet forest from 50 to 800 m altitude.
Balaka macrocarpa is endemic to Fiji, part of the Polynesia-Micronesia Hotspot. In Fiji, it is know from three widely separate populations, one on the island of Viti Levu, one from the foothills of Mt. Sorolevu, on Vanua Levu, and another from the Natewa Peninsula (also known as the Cakaudrove or Tunuloa Peninsula) of Vanua Levu. The Natewa Peninsula population is a historical record and has not be visited in recent years. This palm is an understory palm of wet forests at 200–400 m elev. It is reported to be locally common on slopes in undesturbed forests. (iucn.org)
Fiji. This palm is a Fijian endemic restricted to two small areas in each of the two main islands of Viti Levu, Vanua Levu. The best known population is from the upper Nabukavesi Creek Catchment in Namosi on Viti Levu; and two small populations are known from the Vanua Levu. This palm is an understorey or semi-emergent palm in wet forest from about 200-400 m where it grows on slopes or drainage lines in undisturbed forest and where it may be very locally common. (naturefiji.org)
Description
Balaka macrocarpa is one of six taxa believed to be present in Fiji. It is a single-stemmed palm up 8 m tall. The slender stem is 5–10 cm in diameter with conspicuous leaf-scars. The leaves are pinnate, and the leaflets are slightly sigmoid in with tips that are characteristically praemorse. Inflorescences are borne below a conspicuous green crownshaft. The male flowers have many stamens and are borne alongside female flowers. The fruits are red. The endocarp is five-sided and conspicuously “beaked” at the apex (the “rostrum”). This species can be confused with B. longirostris (which has more wedge-shaped leaflets) and another taxon, provisionally called Balaka ‘bulitavu’ (which appears to have larger fruits). Additional taxonomic study is warranted. (iucn.org)
Balaka macrocarpa is a small palm that grows to only 8 m high with a trunk from 5-10 cm in diameter. The tree trunk is green in colour, with conspicuous pale recent leaf nodes; lower down, the trunk is usually heavily adorned with epiphytes and moss. This palm has a compact crown of 7-12 ascending and slightly arching fronds that reach up to 2.5 m in length, and a bulging green crownshaft. The fronds bear wide, well-spaced, generally erect, dark green leaflets. The inflorescence emerges from beneath the crownshaft, and may be large and heavily laden. However, the large (3-4 cm long and 1.5 cm in diameter), orange-red mature fruit are rarely encountered. Palms of this species that grow in full shade are larger and more robust than those which emerge through the canopy.(naturefiji.org) Editing by edric.
| Detailed Scientific Description |
|---|
|
To 10 m tall. Stem to 6 cm in diam. Leaves 5 or 6, ascending-spreading, 1.3–2.2 m long; sheath 30 cm long; petiole 10–15 cm long; blade 1.0–1.8 m long; pinnae (1–) 5–7 (–12) per side, elongate, slightly sigmoid or falcate, margins converging toward base and slightly converging toward apex and there obliquely truncate and toothed, to 45 cm long, to 11 cm wide, thick-papery, all nerves obscure adaxially except for prominent and raised midrib, all nerves more conspicuous abaxially but only midrib raised, apical pair much wider and transversely truncate and toothed. Inflorescences 1 or 2 per plant, infrafoliar, 20–40 cm long, 1 (–2)-branched; peduncle 8–20 cm long; rachis 5–8 cm long; 4–6 rachillae, these 10–20 cm long, thick, stiffly spreading; triads mostly only in proximal one-half to two-thirds of rachillae. Staminate flowers with ca. 40 stamens, pistillode twice as long as stamens, flexuous. Fruit 4.0–4.8 × 1.5–2.3 cm, ovoid-ellipsoid, orange-red; fruiting perianth 1.2 cm long; endocarp 3.7–4.2 × 1.4–1.8 cm, with 4, prominent, sharp longitudinal ridges and rostrum 8–15 mm long. (iucn.org) Notes: The elongate, obscurely nerved pinnae, short, 1-branched, compact inflorescence with few, stubby, thick, stiffly spreading rachillae having triads only in the proximal one-half to two-thirds and large fruits distinguish Balaka macrocarpa. The short, compact, mostly simply and few-branched inflorescence and infructescence are distinctive because the floral triads are mostly restricted to the proximal one-half to two-thirds of each rachilla, resulting in a tight clustering of the large fruits. (iucn.org) |
Culture
Comments and Curiosities
Ecology and Behaviour: Regeneration in the Nabukavesi population is fair but mature fruit are very rarely encountered. The large fruit are usually eaten as they approach maximum size, but before ripening. The Masked Shining Parrot Prosopeia personata is the likely culprit, this large parrot rarely, if ever, disperses the fruit, being a seed predator, easily opening the seed with its powerful bill and extracting the soft interior. There are still many aspects of this palm that remain unknown today: its confirmed distribution, growth rate, fruiting season, seed dispersal agent, its habitat requirements, this is much needed information that can contribute towards the conservation and management of this species. (naturefiji.org)
| read more |
|---|
|
Conservation: The current populations of B. macrocarpa are quite small. The population along the Nabukavesi Creek was estimated in 1996 at about 200 mature trees. Mahogany plantations are being established close to this population and if these plantations are extended further, then they will pose a major threat. As is the case for other native palms in Fiji, rats are one of the main predators of Fiji palms, and are quite destructive as they not only eat the palm fruit but also the germinating seeds. Rat predation on germinating seeds continues to be a great threat to the regeneration and recovery of the Balaka populations. This palm is obviously a source of food to the Masked Shining Parrot. The parrots predation on the palm probably was not a problem in the past when the population would most likely have been higher. However, with the declining Balaka population, parrot predation is a threat to the regeneration of this palm. Other than determining the conservation status of B.macrocarpa as Critically Endangered, and assigning it a Schedule 2 status in the ESP Act (2002), there are no known efforts to ensure that this species does not become extinct. The location from which the original specimen that was used to describe this palm was taken from is now unknown. All that is known is that it was collected from the Natewa Peninsula, Cakaudrove, Vanualevu. The best known population of this from the upper Nabukavesi Creek catchment in Namosi on Vitilevu, and even this population is threatened by the spread of Mahogany plantations. Other than determining the conservation status of B.macrocarpa as Critically Endangered, and assigning it a Schedule 2 status in the ESP Act (2002), there are no known efforts to ensure that this species does not become extinct. The location from which the original specimen that was used to describe this palm was taken from is now unknown. All that is known is that it was collected from the Natewa Peninsula, Cakaudrove, Vanualevu. The best known population of this from the upper Nabukavesi Creek catchment in Namosi on Vitilevu, and even this population is threatened by the spread of Mahogany plantations. (naturefiji.org) Clarification of the taxonomy of Fijian Balaka species is imperative, in order to understand extents of occurrence of individual species. In the case of B. macrocarpa and B. ‘bulitavu,’ the question of species definition is not merely academic: If two species are recognized, the threats to the survival of each species are even more acute than if only one species is recognized. Molecular methods may offer some insight into species boundaries. Once species boundaries are established, assessments of genetic diversity would be useful. If fruits could be protected against predation by parrots (and possibly rats), seeds could be produced for ex situ conservation collections. Immature plants are cultivated in some gardens in Fiji; it is not known to be cultivated outside of Fiji. (virtualherbarium.org) |
- IMAGE GALLERY
Fiji. Photo-naturefiji.org
Fiji. Photo-naturefiji.org
Fiji. Photo-naturefiji.org
Fiji. Photo-naturefiji.org
Jeff Marcus Garden in Hawaii. Photo by Paul Craft.
Jeff Marcus Garden in Hawaii. Photo by Paul Craft.
External Links
References
Phonetic spelling of Latin names by edric.
Special thanks to Geoff Stein, (Palmbob) for his hundreds of photos.
Special thanks to Palmweb.org, Dr. John Dransfield, Dr. Bill Baker & team, for their volumes of information and photos.
Glossary of Palm Terms; Based on the glossary in Dransfield, J., N.W. Uhl, C.B. Asmussen-Lange, W.J. Baker, M.M. Harley & C.E. Lewis. 2008. Genera Palmarum - Evolution and Classification of the Palms. Royal Botanic Gardens, Kew. All images copyright of the artists and photographers (see images for credits).
Many Special Thanks to Ed Vaile for his long hours of tireless editing and numerous contributions.
