Description:
Arrowhead vine (Syngonium podophyllum) invading a premises.
Syngonium podophyllum has alternate, three-lobed, arrow-shaped leaves that vary in size, shape and color with age and cultivar variety. Juvenile leaves are simple, entire, and sagittate with silvery-white veins or centre, bounded by green. Mature leaves are compound, dark green, and segmented into three leaflets, developing with age to 5–9 leaflets. The central leaflet is the longest. Leaflets are generally dark green above and pale green below and leaves and stem contain a milky sap. It has four to eleven flower spikes (spadixes) which develop in leaf axils, each comprising 6–9 green tubular flowers, enclosed in a creamy-white to green modified leaf (a spathe), similar to that of an arum ‘lily’. Its fruits are red to reddish-orange with many black or brown seeds within a soft, grayish pulp . However, S. podophyllum rarely fruits even within its native range
Habitat description:
Syngonium podophyllum requires moist, well-drained, fertile soils and prefers shady conditions. Within its native
Arrowhead vine (Syngonium podophyllum) in Habitat and close up.
range in Central America it is most frequent in tropical forests but also occurs in premontane wet forest. It ranges in elevations from sea level to 1000 m but is more abundant below 750 m and especially abundant between 100 and 500 m. S. podophyllum is known to grow in sandy and loam soils and within a pH range of 5.5-6.5.
General impacts:
Syngonium podophyllum can established dense populations that displace surrounding vegetation. It has the ability to spread in the deep shade of intact forests, forming a dense mat on the forest floor as well as climbing trees. The stems by which it climbs are thick and fleshy giving them a weight much heavier than most native vines, thus potentially making trees top heavy and more susceptible to toppling in a strong wind. Category I invasive in Florida where it is known to displace native plants including rare ferns. In several areas of St. Lucie and Indian River counties of Florida, S. podophyllum has created a thick ground cover that is largely impenetrable to other plants, and its extensive root system makes the plant extremely difficult to remove. Similarly, it has completely dominated the groundcover layer along one area of the Mount ‘Alava trail in the National Park of American Samoa, seemingly to the exclusion of all other species and has a tendency to climb and cover the trunks of most of the mature trees in the area. S. podophyllum may cause mild to severe poisoning if ingested.
Geographical range:
Native range: Belize, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, El Salvador, French Guiana, Guatemala,
Florida is the Main Habitat for Arrowhead vine (Syngonium podophyllum) in America.
Guyana, Honduras, Mexico, Nicaragua, Panama, Peru, Trinidad and Tobago, Suriname, Venezuela
Known introduced range: American Samoa, Australia, Bahamas, Christmas Island, Federated States of Micronesia (FSM), Florida (USA), French Polynesia (Polynésie Française), Hawaii, New Caledonia (Nouvelle Calédonie), Niue, Puerto Rico, Rota Island, Singapore, Solomon Islands, South Africa, Tonga, Virgin Islands
Management information:
Preventative measures: A Risk assessment of Syngoinum podophyllum by the Pacific Island Ecosystems at Risk yielded a high risk score of 15 ‘reject the plant for import (Australia) or species likely to be of high risk (Pacific). It is considered a potential invasive and sleeper weed by the World Wildlife Federation.
Physical: S. podophyllum may be removed by hand pulling or mechanical removal. It is difficult to eradicate and may reproduce from small root and plant fragments. All vegetation must be removed to achieve eradication and multiple treatments are usually required. Hand pulling is typically only effective on isolated plants and small infestations. Discarded plant materials should be bagged and properly disposed. Gloves should be worn when removing S. podophyllum, as sap can be irritating to sensitive individuals.
Chemical: Several herbicides are known to control Syngonium podophyllum including glyphosate, 2,4-D, fluroxypr, and Metsulfuron-methyl. Glyphosate should be mixed at 360 g/L and diluted 1 L/100 L of water. 2,4-D should be 500 g/L and 4 mL/ 1L of water. Fluroxypyr should be 200 g/L and 0.5-1 L/ 100 L of water. Metsulfuron-methyl should be 600 g/kg and 10 g / 100 L of water plus a wetting agent. All may be applied by a spot spray.
Integrated management: PIER recommends hand pulling combined with spraying resprouts with 3% Roundup (glyphosate) or applying 10% Garlon 4 (triclopyr) to stems. Foliar application of 3% Garlon 4 in water with a surfactant is also effective. Multiple treaments are required.
