TROPICAL ECOSYSTEMS / Bamboos, Palms and Rattans 1675 Weediness Bamboos, Palms and Rattans Some Acacia species have become serious weeds. I R Hunter and N Bystriakova, International Network Exotic Australian Acacia species (e.g., A. saligna, for Bamboo and Rattan, Beijing, China A. cyclops, A. melanoxylon,andA. dealbata) have & caused serious weediness problems in South Africa, 2004, Elsevier Ltd. All Rights Reserved. Portugal, and Chile, whilst New World and African Acacia species (e.g., A. farnesiana, A. nilotica) have caused problems in Australia. The weediness of Acacia species means that their use in agroforestry and Taxonomy/Genetics amenity situations must be considered very carefully. Bamboos: Poaceae (Gramineae) See also: Biodiversity: Biodiversity in Forests. Ecology: The family Poaceae comprises about 12 000 species Reproductive Ecology of Forest Trees; Molecular Biology in about 700 genera. Twelve subfamilies are recog- of Forest Trees; Population, Conservation and Ecological nized, of which the Bambusoidea is one. This Genetics. Landscape and Planning: Landscape Ecology, subfamily includes approximately 1200 species with- Use and Application in Forestry. Medicinal, Food and in the tribes Bambuseae (woody bamboos) and Aromatic Plants: Edible Products from the Forest; Forest Olyreae (olyroid or herbaceous bamboos). Biodiversity Prospecting; Medicinal and Aromatic Plants: Bamboos are forest grasses. The most ancient Ethnobotany and Conservation Status. Tree Breeding, grasses were tropical forest dwellers but, as the Practices: Tropical Hardwoods Breeding and Genetic higher grasses diversified into open areas, the true Resources. Tropical Forests: Monsoon Forests (South- bamboos were the only major lineage of the family to ern and Southeast Asia); Tropical Dry Forests; Tropical Moist Forests; Woody Legumes (excluding Acacias). adapt to the forest habitat. Bamboos are set off from other grasses by the predominance of certain ‘bambusoid’ structural characters, many of which Further Reading are considered to be ‘primitive’. The most easily recognizable vegetative features that distinguish the Barnes RD, Fagg CW, and Milton SJ (1997) Acacia erioloba: bamboos are the prominent development of a Monograph and Annotated Bibliography.TropicalFor- rhizome system, the woodiness and strong branching estry Papers no. 35. Oxford, UK: Oxford Forestry Institute. Doran JC and Turnbull JW (1997) Australian Trees and of the culms, the presence of petioles on the leaf Shrubs: Species for Land Rehabilitation and Farm blades, and the difference in form between the Planting in the Tropics. ACIAR Monograph no. 24. sheaths clothing young culm shoots and those borne Canberra: Australian Centre for International Agricul- on the leafy twigs. To these may be added floral tural Research. characters such as well-developed lodicules, in most Guinet P and Vassal J (1978) Hypotheses on the species three in number, and a style consisting differentiation of the major groups of the genus Acacia typically of a single column, bearing one, two, or (Leguminosae). Kew Bulletin 32: 509–527. three (rarely more) stigmas. Janzen DH (1974) Swollen-thorn Acacias of Central The bambusoid grasses are naturally distributed in America. Smithsonian Contributions to Botany 13: 1–131. all continents except Europe and Antarctica. Bam- Maslin BR (2001) Flora of Australia, vol. 11A/B, Mimosa- boos appear more or less prominently in the natural ceae, Acacia, Part 1–2. Canberra: Commonwealth Scien- tific and Industrial Research Organization Publishing. vegetation of many parts of the tropical, subtropical, Maslin BR, Miller JT, and Seigler DS (2003) Overview of and mild temperate regions. The approximately the generic status of Acacia (Leguminosae: Mimosoi- 1100 species of woody bamboos are distributed deae). Australian Systematic Botany 16: 1–18. from 461 Nto471 S latitude and from sea level to New TR (1984) A Biology of Acacias: A New Source Book 4300 m in equatorial highlands, whereas the ap- and Bibliography for Biologists and Naturalists. Mel- proximately 110 species of herbaceous bamboos bourne, Australia: Oxford University Press. occur overwhelmingly in the New World, with only Pedley L (1986) Derivation and dispersal of Acacia two Old World representatives. The herbaceous (Leguminosae), with particular reference to Australia, bamboos occur principally in moist forests between and the recognition of Senegalia and Racosperma. 291 N and 341 S latitude and are only occasionally Botanical Journal of the Linnean Society 92: 219–254. found above elevations of 1000 m, rarely to 2700 m. Ross JH (1979) A conspectus of the African Acacia species. Memoirs of the Botanical Survey of South Africa 44: The natural distribution of bamboo in the world has 1–155. been greatly modified by human intervention. Turnbull JW (1986) Multipurpose Australian Trees and Of the 60–70 genera of woody bamboos, only Shrubs. Canberra: Australian Centre for International Arundinaria occurs in both the Old World and New Agricultural Research. World. Currently, 20 genera of solely New World 1676 TROPICAL ECOSYSTEMS / Bamboos, Palms and Rattans woody bamboos are recognized, so there are 21 New they bear a rosette consisting of coriaceous, either World woody genera. Although nearly twice as many palmate or pinnate, leaves, up to some meters long. Old World genera are recognized, there are approxi- The stem may remain quite slender, in which case mately 430 species of New World woody bamboos, it turns to a creeping habit (rattan/Calamus), or compared with 500–600 Old World species. otherwise it may be very short in acaulescent species In the Old World, the monsoon-belt of Southeast (Phoenix acaulis). Another feature peculiar to this Asia with southern China is the main center of family is that the stem reaches its ultimate growth in diversity of the bambusoid grasses. In the New diameter before it starts its growth in height. Indeed, World, Brazil (including the Amazon basin and the palms lack any secondary growth. Inflorescences are Atlantic forests) has the greatest diversity of genera spadix-like, at first enveloped by a spathe or by leaf and species, followed by the Andes (Venezuela to sheaths opening up at anthesis. Bolivia) and Mexico and Central America. The fruit may be either a berry (e.g., Phoenix)ora Bamboos have a great industrial and cultural drupe (e.g., Cocos). Only one fertilized locule carries significance, particularly in East Asia, although fewer on developing, whilst all others wither, so that the than 100 species are generally used. fruit contains one seed only. Pollination is mostly anemophilous; accordingly, the plant produces a large amount of pollen for this purpose. Palms: Arecaceae (Palmae) The Arecaceae include plants of enormous eco- The family Arecaceae is a large group comprising nomic importance for human beings, amongst them approximately 2500 arboreal species to be found the coconut palm (Cocos nucifera) and the date palm throughout equatorial, tropical, and subtropical (Phoenix dactylifera). Several species are employed areas of the world where they feature as a very in the production of vegetable fibers (Sabal, Cha- peculiar element of the landscape. The main geo- maerops, Trachycarpus, Borassus). African oil palm graphical areas having played the role of differentia- (Elaeis guineensis) supports a huge industrial oil tion centers are Africa’s equatorial coasts, the industry. Rattans are the basis of a large furniture Indonesian region, the Sunda Isles, Oceania, Brazil’s and matting industry. Other palms with high coasts, Amazonia, and the Antilles. It was during the potential as food sources include Bactris gasipaes, Cretaceous period that this group had its largest Euterpe oleracea, E. precatoria, Jessenia bataua, diffusion and differentiation, leaving behind several Mauritia flexuosa,andOrbignya phalerata. fossil remains of trunks and leaves. Palms are also used in milder temperate-climate The family is traditionally divided into a number regions to provide trees for parks, gardens, squares, of subfamilies: (1) Phytelephasieae, characterized and avenues. Among the most widely used to this end by flowers without a perianth, a large number of are Phoenix canariensis, P. dactylifera, Washingtonia stamens in male flowers and female flowers bearing filifera, W. robusta, Syagrus romanzoffiana,and a multilocular ovary (4–9 locules), and infructes- Trachycarpus fortunei. cences (Phytelephas); (2) Coryphoideae, exhibiting floral characters typical of the family: free carpels, Rattan: Calamoideae berry-like fruits, pinnate or fan-shaped leaves (Phoenix, Chamaerops, Trachycarpus, Livistona, Rattans belong to the Calamoideae, a large sub- Sabal, Washingtonia); (3) Borassoideae, character- family of palms. There are around 600 different ized by fan-shaped leaves, perianth typical of the species of rattan belonging to 13 genera and these are family, syncarpous ovary (Hyphaene, Borassus, concentrated solely in the Old World tropics; there Lodoicea); (4) Lepidocaryoideae, characterized by are no true rattans in the New World. All of the syncarpous ovary and fruits covered with imbricate species within the Calamoideae are characterized by scales (Raphia, Metroxylon, Calamus); (5) Cerox- overlapping reflexed scales on the fruit and all of yloideae, characterized by syncarpous ovary and these climbing palms are spiny, a necessary preadap- pinnate leaves (Arenga, Ceroxylon, Areca, Cocos); tation to the climbing habit. Of the 13 genera of (6) Nipoideae, characterized by male flowers bear- rattan, three