Rubber Vine 1695843 224758543 2008-07-10T08:28:23Z Ethel Aardvark 4037911 /* As a weed in Australia */ {{Taxobox | name = Rubber Vine | image = Cryptostegia grandiflora.jpg | image_width = 210px | image_caption = Flowers and leaves of Rubber Vine | regnum = [[Plantae]] | divisio = [[Flowering plant|Magnoliophyta]] | classis = [[Magnoliopsida]] | ordo = [[Gentianales]] | familia = [[Apocynaceae]] | genus = ''[[Cryptostegia]]'' | species = '''''C. grandiflora''''' | binomial = ''Cryptostegia grandiflora'' | binomial_authority = [[Robert Brown (botanist)|R. Br.]] }} {{Cleanup|date=June 2008}} '''Rubber Vine''' (''Cryptostegia grandiflora'') is a woody-[[Perennial plant|perennial]] [[vine]] native to south-west [[Madagascar]]. It is a significant weed in northern [[Australia]], sometimes regarded, in fact, as the worst [[weed]] in all of Australia. It has also been introduced to most other tropical and subtropical regions by man because of its attractive [[flower]]s and the fact that its latex contains commercial quality [[rubber]] (hence the name). It is now naturalised in the Caribbean, [[East Africa]], [[Mauritius]], [[India]], [[Southeast Asia]], [[Latin America]], the southern [[United States]], [[Fiji]] and [[New Caledonia]]. Seeds germinate after the first rains of the wet season, but growth does not become rapid until well after the wet season begins. However, if enough water is available rubber vine can grow as much as five metres in one month. Flowering usually occurs after the wet season ends, along with fruit set. It is usual to find both mature and immature fruit on rubber vine at any one time, however. Rubber vine seeds are dispersed by winds and [[flood]]ing, this being particularly important in Australia where very large river floods can occur. ==As a weed in Australia== Rubber vine can grown up to 2 metres (m) tall as a shrub, but when it is supported on other vegetation as a vine it can reach up to 30 m in length. Rubber vine prefers areas where annual rainfall is between 400 and 1400 millimetres (mm), and is well adapted to a [[monsoon]]al climate. The fact that it can grow maximally on an annual rainfall of 1700 millimetres but seeds best on an annual rainfall of 400 millimetres or less means rubber vine thrives on - in fact ''requires'' - the extreme variability of [[precipitation (meteorology)|rainfall]] and [[runoff (water)|streamflow]] so characteristic of central [[Queensland]]. This extreme variability (''four times'' that of other countries to which it has been introduced) is almost certainly why rubber vine has become a major weed in Australia and not any other country in which it has been introduced. Rubber vine is believed to have a potential range in Australia from about Coen in [[Cape York Peninsula]] to [[Port Hedland]] in the [[Pilbara]], but has not yet moved much beyond Queensland. It is a major threat to [[gallery forest]]s along [[river]]s in northern Australia because it can strangle and kill the native trees by climbing over them and completely eliminating access to light. It can also do the same thing in [[savanna]] woodlands away from watercourses. Rubber vine is also extremely toxic to all livestock: less than 10 [[gram|g]] of rubber vine leaves can kill a 400 [[kilogram]] [[horse]] within six days, and it is also highly toxic to [[cow|cattle]], [[sheep]] and [[goat]]s. However, it is extremely unpalatable and only causes death in dry seasons when green [[grass]] is very scarce. Control of rubber vine has relied on importing biological agents from its native habitat in southwestern Madagascar, the most important of which is the "rubber vine [[rust (fungus)|rust]]", ''Maravalia cryptostegiae''. In some areas near [[Charters Towers]], this rust has infected most rubber vine plants, but its effect has not been great enough to stop the spread of the plant westwards. The "rubber vine moth", ''Euclasta whalleyi'', was introduced earlier than the rust (in 1988) but has not proved very effective. The extreme remoteness of most rubber vine infestations rules out mechanical or chemical control for dealing with the plant. They mention this in King Leopold Ghost book. ==References== * Land Protection, Queensland Department of Natural Resources, Mines and Energy. [http://www.weeds.org.au/docs/Rubber_Vine_Mgmnt.pdf Rubber Vine Management, March 2004] (pdf file) * McMahon, T.A. and Finlayson, B.L.; ''Global Runoff: Continental Comparisons of Annual Flows and Peak Discharges''; published 1992 by Catena Verlag. ISBN 3-923381-27-1. [[Category:Apocynaceae]] [[Category:Invasive plant species]] [[Category:Poisonous plants]] [[Category:Flora naturalised in Australia]] [[de:Cryptostegia grandiflora]] [[lt:Uokas]] [[th:ดาวประดับ]]