EXOTIC INVASIVE , US VIRGIN ISLANDS Rubber (Cryptostegia grandiflora) Milkweed Family (Asclepiadaceae) Native Range Madagascar

Vines are with a climbing growth habit. They rely on trees or Preferred Habitat other objects for structural support and can often grow quickly. Most Rubber vine prefers rainfall levels be- vines produce their own food and are not true parasites, although tween 400 and 1400 mm/yr, which in- they can harm other plants. The vines featured here grow so aggres- cludes most of the Virgin Islands. It sively that they smother other plants by blocking out sunlight and thrives in agricultural areas, pastures, killing them. riparian zones, forests and wetlands. Roadsides, fence lines, dry forests and disturbed areas are also readily colo- Description its aggressive, invasive behavior. Land- nized. Rubber vine has bell shaped, showy pur- scape planting may appear harmless or ple that are usually produced even attractive, they the are also the Dispersal after heavy rains. It climbs with whip-like seed source for a invasion harming The climbing vine produces pairs of seed shoots that can reach 120 feet tall when the local ecology. capsules containing hundreds of wind- supported by a tree, or a six foot clump born seeds. The pods themselves can unsupported in an open field. The leaves float in fresh or salt water for months are smooth, glossy and thick. Leaves, with viable seeds intact. In St. Croix, a vines and seed pods exude a toxic white large patch near the Buccaneer Hotel is sap when broken. Rigid horn-like seed spreading via floodwater throughout a pods form in pairs and contain 300 to roadside weltand. 400 small brown seeds. It is toxic to live- stock and is known to kill cattle in Aus- Management Options tralia and reduce the quality of pastures. Virgin Islanders can help by first remov- ing rubber vine from around their homes. There are four methods of con- trolling or removing rubber vine; biologi- cal controls (introducing a rust disease), herbicides, fire, and mechanical. In the Virgin Islands, physically chopping and pulling out individual plants or clumps is (Rubber Vine Mat Over Tree Canopy) recommended. Do not remove clumps Ecological Threat of the vines and discard them directly (Rubber Vine ) Rubber vine climbs and smothers plants, into the bush, as the vine can root itself and spread. Instead, let the chopped Historical Introduction killing native vegetation and blanketing areas so other plants cannot grow. The vegetation sit in the direct sun for several Rubber vine has been introduced days o dry out or burn it on site. Consider around the tropical world primarily by Global Invasive Species Database desig- nated it among “100 of the World’s planting native species or purple sandpaper gardeners and plant collectors fascinated vine instead of rubber vin in landscapes. by its attractive purple blooms. Internet Worst Invasive Alien Species”. In Austral- seed companies still sell this plant online ia, rubber vine has become one of the and usually only give a passing mention most invasive plants. There is a nation- Additional Information to the aggressive spread and the ecologi- wide weed management plan that costs Invasive Species Specialist Group: www.issg.org cal and economic harm it can cause. In millions each year to control it and costs the Virgin Islands it is still occasionally tens of millions more in lost productivity http://www.weeds.gov.au/ planted by landscapers unfamiliar with of agricultural land. publications/guidelines/wons/pubs/c- grandiflora.pdf The VI Department of Agriculture and the USDA are an equal opportunity provider and employer. www.geographicconsulting.com/services/invasive-species/ EXOTIC INVASIVE SPECIES, US VIRGIN ISLANDS Coral Vine ( leptopus) Family() Native Range Mexico Vines

Description Historical Introduction Dispersal Coral vine is a fast growing, climbing vine Coral vine is widely cultivated as a land- One of the challenges in controlling coral from Mexico capable of quickly reaching scape plant in the southern United States vine is that seeds are produced prolifical- 40 feet tall in the Virgin Islands. It attach- and throughout the tropics because of its ly and are dispersed in a variety of ways. es to trees, fences, utility poles or other showy pink flowers, fast growth and abil- Fruit are eaten and spread by wildlife or supportive structures using its coiled ten- ity to cover fences and walls. It has been can float on water and travel down- drils. The leaves are heart shaped and it is found in the Virgin Islands since before stream. Underground tuberous roots will known for its large, showy clusters of 1960, but in recent years it has spread vigorously re-sprout new shoots and bright pink flowers (sometimes white). aggressively in the wild; growing in dense leaves when the plant is cut. Fruit are small, dry and inconspicuous carpets. containing many black seeds. Management Options Ecological Threat Coral vine is extremely difficult to re- Coral vine grows aggressively, climbing move. For home-owners cleaning small and forming dense blankets that can areas, the best option is mechanical re- smother the plants on which it grows. It moval, but will require vigilant cutting is considered a Class II Invasive Exotic by and re-cutting of new sprouts. Plants will the Florida Invasive Plant Council. The likely continue to re-sprout until the un- plant is not a true parasite because it derground tubers are removed. There is does not take nutrients from a host, but no proven effective method for remov- it can kill by smothering. ing it from large areas in the Virgin Is- lands. Preferred Habitat Additional Information Coral vine prefers full sun but can also tolerate some shade. In the Virgin Is- http://www.invasivespecies.gov/ lands , moist habitats are more suscepti- http://www.hawaiiinvasivespecies.org/ ble to invasion. It tolerates poor soil and http://plants.ifas.ufl.edu/node/40 (Coral Vine Flowers and Leaves) periods of drought.

Dodder Vine—A native vine that is a weed, but not an invasive plant The dodder vine (Cuscuta americana), with its distinct orange tendrils, is not an exotic inva- sive plant. It is native to the Virgin Islands, although many would rather never see it again. This plant is a true parasite and pierces the tissue of a host plant with small suckers and pulls nutrients from it. It does not produce its own food from photosynthesis and adult dodder vines do not have roots. Scientists recently discovered dodder can “smell” the scent of healthy plants and seek them out as food like an animal. Despite all of these unwelcomed behaviors, dodder is a member of the native plant community and does not act or spread like an invasive plant. Infestations are generally seasonal and localized over smaller landscapes. Farmers and home-owners can physically remove the orange vines and pile them up to dry out and die. A widespread eradication plan for this plant is not necessary.

(Dodder Vine Covering Trees) Fact Sheets Produced by Geographic Consulting on behalf of the Virgin Islands Department of Agriculture, Forestry Divi- sion. For more information please contact the VIDOA at (340)-778-0997. This project made possible through a grant from the USDA Forest Service (Grant # 08-CA-11120107-024) www.geographicconsulting.com/services/invasive-species/