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Species
Paederia foetida L.
IUCN
NCBI
EOL Text
Studies highlighting conditions most suitable for skunkvine seedling establishment and growth are lacking. A study along the Arakawa River floodplain near Urawa City, Japan, suggests that skunkvine seedlings establish on disturbed sites. There were 0.3 skunkvine seedlings/m² in moist tall grasslands that were burned each winter for 30 years. There were 1.8 skunkvine seedlings/m² on sites that were "cleared" in the winter for the last 6 years. Methods for clearing vegetation were not described. No skunkvine seeds were trapped on the burned site, but 16.7 skunkvine seed/m² were trapped on the cleared site [30].
During a recent expansion of skunkvine in Mead Gardens Park, Winter Park, Florida, park officials estimated that stems grew 2 to 3 inches (5-7.5 cm) per day. Skunkvine had almost completely covered 60-foot (18 m) magnolia (Magnolia spp.) trees. Rapid growth coincided with rainy weather [35].
Information on state-level noxious weed status of plants in the United States is available at Plants Database.
More info for the terms: cover, litter, mesic
A field study conducted in west-central Florida suggests that skunkvine seed banks are short-lived. Researchers placed skunkvine fruits in mesh bags in 3 habitats: a mixed mesic forest dominated by sweetgum (Liquidambar styraciflua), southern magnolia (Magnolia grandiflora), and baldcypress (Taxodium distichum); the edge of the mixed forest; and an open grassland dominated by St Augustine grass (Stenotaphrum secundatum). Fruits were naturally buried over time by leaf litter and soil-disturbing animals. During the course of the study, 26% of seeds were damaged by weevils and weevil larvae. The number of viable seeds decreased significantly over time (P<0.001), but seeds survived longer in the forest interior than at the forest edge or in the grassland. After 1 year, 38% of seeds were viable in the interior, 2% at the edge, and 2% in the grassland. After 2 years, 4.7% of seeds were viable in interior, 0.4% at the edge, and 0% in the grassland. For all habitats, just 0.2% of skunkvine seeds were viable after 3 years. Researchers suggested that high temperature fluctuations and/or high light levels in the grasslands may have encouraged germination of skunkvine seeds. Canopy cover was 86% in the forest interior, 68% at the forest edge, and less than 1% in the grassland [26].
Preserve Selection and Design Considerations: Paederia foetida is a fast-growing exotic pest vine capable of causing mortality of canopy trees and understory vegetation and disrupting community structure and function. Preserves located within the known range of this species should be surveyed to determine if it is present. If so, an eradication program should be initiated as soon as possible to prevent the destruction of native species and communities. In assessing areas for potential acquisition, the presence of P. foetida should be considered in evaluating desirability of acquisition, and in developing management plans.
Management Requirements: 1. Erradication programs should be designed and implemented for this species on all conservation lands where it is present.
2. In fire-adapted communities (e.g. Sandhill), prescribed fire should be used to reduce the density and cover of Paederia foetida, and follow-up herbicide treatments should be employed.
3. In relatively non-fire adapted communities, the primary management goal should be to prevent the mortality of canopy and sub-canopy trees through hand-cutting of aerial stems. Herbicide treatments of basal and prostrate stems should follow.
4. Preserve managers should work with adjacent land-owners to eradicate P. foetida where possible.
5. Ensure that neither P. foetida nor P. cruddasiana are commercially available through the nursery trade.
Management Programs: In Florida, no significant control programs of P. foetida are known. One management research project utilizing prescribed fire to control P. foetida has been initiated in Hernando County, Florida, and is described below. The City of Winter Park (Orange County, Florida) has also conducted a test treatment of P. foetida utilizing 1.54 percent Roundup (glyphosate) in water at Mead Gardens (Gordon Greger, Landscape Manager, City of Winter Park, personal communication). This treatment has been found to be effective in killing stems immediately adjacent to the treated leaves, but it is unknown if the treatment causes death of individual plants. P. foetida is one of 41 species listed for control at Hawaii Volcanoes National Park; a 2-ha colony of P. foetida was eradicated or nearly eradicated there by broadcasting 5% Tordon 22K (Tunison 1992).
Significant control programs of P. cruddasiana in Dade County, Florida, however, have been initiated by the Metro-Dade County Department of Parks and Recreation (Metro-Dade Parks) at the R. Hardy Matheson Preserve (formerly the Snapper Creek Hammock Preserve) and at Matheson Hammock Park, and by Ecohorizons, Inc. at The Montgomery Foundation property in Coral Gables. Ecohorizons, Inc. has utilized 10 percent Garlon 4 (tryclopyr) in diesel fuel and Metro-Dade Parks has utilized 10 percent Garlon 4 in Penevator Basal Oil on basal stems to cause mortality of P. cruddasiana. A complete kill, however, may not be accomplished if the treated plant is well-rooted at several nodes, and follow-up treatments of individual rooted stems may be necessary. Ecohorizons, Inc. has also utilized 50 percent Garlon 3A in water on the surface of cut basal stems to cause mortality of P. cruddasiana. One percent Roundup (glyphosate) in water applied to leaves resprouting from cut basal stems has also been successfully utilized by Ecohorizons, Inc. to cause mortality of smaller individuals of P. cruddasiana. Metro-Dade Parks has successfully utilized three percent Roundup to cause leaf-drop of P. cruddasiana, thus allowing for better targeting of stems with Garlon 4 or 3A (Laura Flynn, Biologist, Metro-Dade Parks, personal communication). This technique should not be used, however, unless the cover of Paederia is effectively 100 percent in order to prevent off-target damage to native vegetation. Unlike some vines (e.g., Cissus sicyoides), the aerial portions of P. cruddasiana may be killed by severing the aerial stem from the rooted portions of the plant. This may be an effective short-term measure to prevent the mortality of trees and shrubs in infested areas. Seedlings of P. cruddasiana are easily hand-pulled.
Control treatments developed for P. cruddasiana are expected to be effective on P. foetida.
Monitoring Programs: In Florida, no significant programs monitoring the distribution, density, cover, spread, or impacts of P. foetida are known. In Hawaii, there is a program to monitor for presence of P. foetida at Hawaii Volcanoes National Park as part of an overall exotic species control program (Tunison and Zimmer 1992). Surveys for exotic weed species are made every three months along roadsides, annually in Special Ecological Areas, and twice yearly in developed areas and along trails.
Management Research Programs: Florida: Doria Gordon (The Nature Conservancy, Gainesville, Florida) and George Gann-Matzen (Ecohorizons, Inc., Goulds, Florida) have initiated a research project on the effects of prescribed burning on P. foetida in historically fire-excluded Sandhill at the Janet Butterfield Brooks Preserve in Hernando County, Florida (Gordon and Gann-Matzen 1993). Preliminary results indicate that prescribed fire is effective in controlling P. foetida in this natural community. Twenty-five plots were established in which the number of Paederia stems climbing on individual trees at DBH level were measured. In the initial sample a mean of 13.2 stems per tree was recorded. The site was burned March 3, 1992; one month post-burn no surviving Paederia stems were recorded. The site was sampled again approximately one year post-burn, and a mean of 0.61 stems per tree was recorded (a 95% decrease). This was a statistically significant change (p<0.05) using a paired t-test. Changes in Paederia stems on control trees during the same period were not found to be statistically significant. Five macroplots within the burned plot area were also sampled during 1992-1993 to determine the number of free-standing vine "ladders" reaching into the canopy. One-month post-burn showed no survival, and one-year post-burn showed a reduction in the mean density of ladders in the macroplots. The site was burned a second time March 12, 1993. All plots were re-monitored approximately one year post-burn. During this monitoring event a further 52% decrease in P. foetida stem numbers per tree was recorded (Doria Gordon, State Ecologist, The Nature Conservancy, personal communication).
Hawaii: No scientific research from Hawaii is known.
Louisiana: No scientific research from Louisiana is known.
South Carolina: No scientific research from South Carolina is known.
Management Research Needs: 1. Determine if methods used to eradicate P. cruddasiana will be effective on P. foetida.
2. Conduct research on the basic biology of P. foetida including methods of pollination, seed dispersal, growth rates, sensitivity to cold, etc.
3. Conduct basic ecological research on the effects of P. foetida on impacted vegetation (by leaves interfering with photosynthesis as well as through root competition), and wildlife.
4. Conduct research to determine origin, infraspecific taxon classification, and genetic makeup of P. foetida in Florida, Hawaii, Louisiana, and South Carolina.
Comments: The foetid smell of P. foetida (presumably sensu auctt., non L., including P. cruddasiana Prain) is due to the presence of methyl mercaptan (Bose et al. 1953-55, in Shukula et al. 1976), and the leaves possess both tonic and astringent properties (C.S.I.R. 1966). Folk medicine attributes a variety of curative properties to P. foetida and it is prescribed for toothache, chest pains, piles, inflammation of the spleen, herpes, and as a diuretic and emetic (C.S.I.R. 1966).
Paederia foetida is and has been cultivated for both its attractive flowers and for its medicinal properties in tropical and subtropical regions, as well as in extratropical areas (Puff 1991b), although it was not included in Hortus Third (Liberty Hyde Bailey Hortorium 1976). In Florida, it is apparently not currently in the nursery trade (cf. Betrock Information Systems 1993). It is unknown if it is in the nursery trade in Hawaii, Louisiana, or South Carolina
Wind and animal dispersal of skunkvine seeds are likely in the United States. From experiments and calculations, researchers estimated that skunkvine seeds falling from 16 feet (5 m) above ground when horizontal winds were 5.9 feet (1.8 m)/s could travel 8.9 feet (2.7 m). Distances increased to 36 feet (10.9 m) and 72 feet (21.8 m) in winds of 23 feet (7 m)/s and 46 feet (14 m)/s, respectively [43].
Although direct evidence of animals dispersing skunkvine seeds in the United States is lacking, several sources indicate that animal dispersal is suspected ([3,28], review by [10]). Field studies in Japanese black pine stands in Japan showed that birds removed an average of 66.9 skunkvine fruits/plant. Brown-eared bulbuls, pale thrushes, dusky thrushes, and Japanese white-eyes were the most common dispersers. These birds consumed whole fruits but also dropped many fruits. During the study, there were 95 skunkvine seeds dropped beneath skunkvine plants, 71 beneath Japanese callicarpa (Callicarpa japonica), 35 beneath linden arrowwood (Viburnum dilatatum), and 32 beneath Japanese honeysuckle (Lonicera japonica). Researchers collected both fruits and exposed seeds. Exposed seeds were likely the result of defecation or regurgitation. Seed viability was not tested [53].
More info for the terms: cover, density, fern, fire management, invasive species, natural, nonnative species, prescribed fire, shrub, shrubs, tree, vines
Impacts: Although quantitative studies on the ecological and economic impacts of skunkvine on invaded habitats are lacking, anecdotal and visual evidence of skunkvine's impact on native plants and vegetation structure is abundant. As of 2005, the Florida Exotic Pest Plant Council listed skunkvine as a Category 1 invasive species based on documented ecological damage. In Florida, skunkvine has altered native plant communities by displacing native species and/or by changing community structure or ecological functions [9]. In Mead Gardens Park in Winter Park, Florida, skunkvine had been established for years, but in 1992, park officials reported that in several months of rainy weather it increased in size and came to occupy 6 acres (2.4 ha) of the 55-acre (22 ha) Park [35].
Photo © 2001 Forest and Kim Starr
Skunkvine has invaded many habitat types and is not restricted to disturbed areas [24]. As of 1996, skunkvine was reported in natural areas of Florida's Hillsborough, Hernando, Pasco, Citrus, Marion, Sumter, Lake, Orange, and Polk counties (Florida Exotic Pest Plant Council 1996 cited in [25]). There have also been recent expansions of skunkvine's nonnative range to the north and south (see Local distibution changes).
Dense shading by extensive skunkvine clones as well as the weight of multiple climbing stems can eventually damage or kill herbaceous vegetation, shrubs, and trees, creating canopy gaps. In these gaps, skunkvine establishment and growth can be rapid, limiting the recruitment of shrub and tree seedlings and saplings and preventing normal forest regeneration (reviews by [10,62]). In the Jungle Botanical Gardens in Iberia Parish, Louisiana, Thomas and McCoy [54] found large skunkvine populations and likened their growth to that of Japanese honeysuckle (Lonicera japonica) and Japanese climbing fern (Lygodium japonicum), two other nonnative species that have negatively impacted wildland habitats. Near Asheville, North Carolina, a recently discovered skunkvine clone was climbing over shrubs, into low tree branches, and along the ground for lengths of up to 13 feet (4 m). The clone had established beneath an American beech (Fagus grandifolia) planted about 6 years earlier. The researcher speculated that skunkvine seed was a contaminant in the tree's root ball or was dispersed by a migratory bird [8]. In Florida, observations suggest that dense skunkvine growth has reduced the density and cover of native herbaceous species [13], and skunkvine has smothered and killed portions of one of the few remaining populations of Cooley's water willow (Justicia cooleyi), a federal endangered species (Bowman and Martin 1995 personal communiciations cited in [25]). In wet disturbed lowland sites of Hilo, Hawaii, and on the island of Maui, skunkvine growth is dense and often forms blankets over other vegetation. On Maui, skunkvine reaches at least 33 feet (10 m) into tree canopies [50].
In Hawaii, skunkvine is linked to economic impacts in ornamental plant nurseries. When skunkvine invades fields used to propagate ornamental plants, control is difficult. Because nontarget effects must be minimized, the number of potential control methods is reduced and often the labor and economic costs associated with control are increased [36].
Control: Control of nonnative invasive species is most effective when it employs a long-term, ecosystem-wide strategy rather than a tactical approach focused on an individual species [29]. When targeting a nonnative species for control, the potential for other invasive species to fill their void must be considered, regardless of the control method used [5].
Fire: For information on the use of prescribed fire to control this species, see Fire Management Considerations.
Prevention: It is commonly argued that the most cost-efficient and effective method of managing invasive species is by preventing their establishment and spread through the maintenance of "healthy" natural communities [29,47,56] and by continual monitoring [19]. Maintaining the integrity of the native plant community and mitigating the factors that enhance ecosystem invasibility are likely to be more effective than managing solely to control the invader [17].
Weed prevention and control can be incorporated into many types of management plans, including those for logging and site preparation, grazing allotments, recreation management, research projects, road building and maintenance, and fire management [57]. See the Guide to noxious weed prevention practices [57] for specific guidelines in preventing the spread of weed seeds and propagules under different management conditions.
Physical or mechanical control: Hand-pulling and cutting the stems of established skunkvines rarely provides effective control [24]. Seedlings and small plants may be easily pulled by hand, but cutting and pulling established stems promotes sprouting (review by [62]). In Florida, skunkvine was sprouting 2 weeks after hand-pulling [52]. Stems within a skunkvine clone found near Asheboro, North Carolina, were pulled or cut in October 1998. Skunkvine sprouts occurred by mid-April 1999 [8]. Researchers recommend careful disposal of cut or pulled stems to limit the number of fruits, seeds, and stem fragments left on the treated site [24]. During seed bank studies conducted in Florida, a fraction of skunkvinve seeds remained viable for at least 3 years, suggesting that treated sites should be monitored for seedlings for at least 4 years [26].
Biological control: There has been testing on a Japanese flea beetle (Trachyaphthona sordida) that appears to be a skunkvinve specialist [37]. As of 2009, no biological controls had been released.
Many factors must be considered and evaluated before biological controls are released. Refer to these sources: [59,64] and the Weed control methods handbook [55] for background information and important considerations for developing and implementing biological control programs.
Chemical control: Sprouting is common after herbicide treatments on skunkvine [28]. A single herbicide application does not control skunkvine [24]. When skunkvine is growing over or in desirable native vegetation, vines should be pulled off of this vegetation before herbicides are applied. Herbicides are considered most effective if applied while skunkvine is actively growing in the spring or summer [28].
A review recommends cutting skunkvine stems and then applying herbicides to cut bases and prostrate stems. This method should increase the effectivness of herbicides and minimize nontarget effects [10], but treated sites should probably be monitored for seedling establishment for at least 4 years [26].
While herbicides are effective in gaining initial control of a new invasion or a severe infestation, rarely do they provide a complete or long-term weed management solution [7]. See the Weed control methods handbook [55] for considerations on the use of herbicides in natural areas and detailed information on specific chemicals.
Integrated management: No information is available on this topic.
More info for the terms: perfect, protandrous, shrubs, swamp
Pollination and breeding system: Skunkvine flowers are perfect, protandrous, and self incompatible [26,41,46]. In the greenhouse, skunkvine flowers protected from insects failed to produce fruit. When researchers artificially cross pollinated flowers, about 70% set fruit [41]. At field sites in Florida, no bagged flowers produced fruits, but more than 20% of unprotected flowers produced fruits [27].
Flowers are insect pollinated. Honeybees and other bees pollinated skunkvine flowers in Ogasawara Islands, Japan [1]. Butterflies were common pollinators in China, Malaysia, and Indonesia [41]. In Florida, 15 insect species visited skunkvine flowers; all insects were native to Florida, except European honey bees (Apis mellifera), which were most common on skunkvine flowers in an open field. Halictid bees were the most common visitors in the swamp forest and at a successional site where trees and shrubs were establishing. The number of insect visits/watch was significantly greater in the swamp forest than at the successional site (P<0.05). Skunkvine flowers produced up to 0.4 mm of nectar by volume, and sugar concentrations ranged from 20% to 35% [27].
Individual skunkvine flowers are short lived, and stigmas are receptive for a short period of time. However, skunkvine may produce many inflorescences each with multiple flowers, so plants may have open, receptive flowers for 6 weeks or more [41]. In Florida, skunkvine plants had multiple open flowers each day. Flowers generally opened before or at dawn and dropped petals by the next morning [27]. Once petals fall, stigmas are no longer receptive [41]. In Ogasawara Islands, Japan, skunkvine produced 11 to 100 flowers/inflorescence and 101 to 1,000 inflorescences/plant [1].
Several medicinal uses of skunkvine are reported in the literature, although their effectiveness has been poorly researched. Skunkvine is said to have diuretic and emetic properties but is most commonly described in the literature as a treatment for rheumatism (review by [39]). Other ailments reportedly treated with skunkvine include: headaches, fevers, toothaches, herpes, chest pains, stomach discomforts, hemorrhoids, juandice, spleen inflammation, low fertility, menopausal symptoms, skin ulcers, and snake bites (reviews by [10,39,46]).
United States
Origin: Exotic
Regularity: Regularly occurring
Currently: Unknown/Undetermined
Confidence: Confident
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | NatureServe |
Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=Paederia+foetida |
More info for the terms: breeding system, vines
Skunkvine reproduces vegetatively and from seed [15,26]; however, observations suggest that fruit production may be limited in some nonnative habitats [8,50]. On the island of Maui, skunkvine regeneration and spread are primarily vegetative, although maybe not exclusively so [49,50]. Vegetative spread from creeping stems can be extensive, and stem fragments are capable of rooting and producing new vines [28].