Lonicera japonica (Japanese honeysuckle)

Lonicera japonica is also commonly known as Japanese honeysuckle. This invasive species is native to East Asia but was brought to Florida in 1875 for agricultural and ornamental purposes (MacDonald et al. 2008). Honeysuckle is a member of the Caprifoliaceae family, which consists of common landscape ornamental plants. In addition to being an attractive ornamental, honeysuckle has been used in places such as highways to control erosion and stabilize banks (MacDonald et al. 2008). However, it grows quickly and can displace native plants, which is why it is considered to be invasive. L. japonica is also very opportunistic and grows well in disturbed areas, fields, roadsides, forest edges and open gaps between other plants (MacDonald et al. 2008). After establishing itself, it can kill native shrubs and vegetation by shading them, or taking away any available water, nutrients and space. L. japonica grows rapidly, has a longer growing season and lacks natural enemies in Florida which enables the vine to thoroughly invade Florida’s natural communities (MacDonald et al. 2008).

Japanese honeysuckle is an evergreen, woody vine that can grow 80-120 feet long. The vine twines and hollows with age. Younger stems are red colored and pubescent and older stems turn brown (MacDonald et al. 2008). Leaves are opposite, ovate shaped, range 1.5 to 3 inches long and may have pubescent petioles. Flowers on Japanese honeysuckle are white to yellow in color, fragrant, and paired in axillary peduncles. Each individual flower is tubular and has a fused corolla with two lips. Flowers are present from April through July and sometimes later in the season. Flower color often helps distinguish Lonicera japonica from other native honeysuckle varieties, especially Lonicera sempervirens (MacDonald et al. 2008). Fruits can also help distinguish between the invasive and native honeysuckles. Native fruits are red or orange in color whereas fruits from Lonicaera japonica are black berries and are produced September through November. Each berry has two or three dark brown or black seeds that are may be up to three millimeters long. Seeds are plentiful after the vine becomes established and dispersal is aided by birds (MacDonald et al. 2008). However, Japanese honeysuckle can also reproduce vegetatively via underground rhizomes or runners aboveground.

Management of Lonicera japonica includes preventative, cultural, mechanical and chemical mechanisms. There are not any current agents of biological control for L. japonica except the limited damage inflicted by grazing deer (MacDonald et al. 2008). Preventative and cultural control methods involve monitoring and preventing plant establishment. This often includes educating those who may potentially plant Japanese honeysuckle and provide alternative native plants such as Campsis radicans (trumpet creeper), Parthenocissus quinquefolia (Virginia creeper), Loniceras empervirens (trumpet honeysuckle) or Asarum canadensis (Wild ginger) (MacDonald et al. 2008). Mechanical control methods may include hand-pulling or hoeing the vine and then removing and destroying all plant material to avoid vegetative growth. Fire can be used to kill seedlings, but often does not kill underground systems. Chemical methods should be timed to be applied after an early frost. This helps to kill the plant at its most susceptible time instead of only killing leaves or foliage (MacDonald et al. 2008).

 

Links:

http://plants.ifas.ufl.edu/node/239

http://www.florida.plantatlas.usf.edu/Plant.aspx?id=232

http://www.plantatlas.usf.edu/flip/plant.aspx?id=21

Paederia foetida (Skunk vine)

Paederia foetida is in the Rubiaceae family and currently on the Florida Noxious Weed List and on the FLEPPC’s Category I list of invasive plants (MacDonald et al. 2008, Wunderlin and Hansen 2008). Native to Eastern and southern Asia, the vine was introduced to Hernando, Florida in 1897 with a prospect as a fiber crop (MacDonald et al. 2008). It expanded beyond its intended purpose and invaded natural areas becoming a nuisance in central and north central Florida (MacDonald et al. 2008).

Like many other invasive species, skunkvine thrives and adapts to many habitat types such as a hydric hammock, but also in other hardwood communities, mixed, pine forests, sandhills, marshes and floodplain forests (MacDonald et al. 2008). P. foetida can actually kill other vegetation and native species by breaking off tree branches with its heavy added weight and by eliminating resources such as sunlight or nutrients when it becomes too dense in understories (MacDonald et al. 2008).

The woody vine gained its name from its “foul smelling” odor when crushed, hence the origin “foetida” (MacDonald et al. 2008). The smell comes from sulfur containing compounds present in the vines’ leaves. Paederia foetida lacks thorns, but makes up for this with its extensive growth. It can grow up to 30 feet into tree canopies or along the ground, always twining to the right (MacDonald et al. 2008). Leaf blades may vary in size, but are arranged opposite and have cordate bases, pointed tips with an entire margin. Although uncommon, leaves may be found arranged in whorls. Petioles are two to three inches long. Flowers are lilac with red centers and are small in size (MacDonald et al. 2008). Fruit are also small, shiny, brown, spherical and contain two seeds. The seeds are one mechanism of reproduction for P. foetida in addition to vegetative reproduction via stems rooting into the soil (MacDonald et al. 2008).

Management tactics include preventative, cultural, biological and chemical methods. Because of regrowth, mechanical methods are often impractical. Preventative and cultural methods include providing a natural biodiversity that doesn’t allow the vine to take root and being aware that the vine is not able to propagate via regrowth when disposed of (MacDonald et al. 2008). Biological control agents have been identified from Japan and include leaf beetles, two sawfly species, a stem gallmaker and moth and a flea beetle. The flea beetle shows the most promise as a biocontrol agent because it feeds on the vines’ root system which prevents the vine from obtaining nutrients and water (MacDonald et al. 2008). Chemical control of the vine is encouraged as an efficient mechanism, but often requires multiple applications to effectively stop any regrowth. Recommended chemicals include Roundup (glyphosate) or triclopyr and application should be applied so as to only target the vine and not the vegetation it is growing on (MacDonald et al. 2008).

Links:

http://plants.ifas.ufl.edu/node/303

http://plants.usda.gov/core/profile?symbol=Pafo3

http://www.florida.plantatlas.usf.edu/Plant.aspx?id=1466

 

Nephrolepis cordifolia (Sword fern)

Nephrolepis cordifoia in a disturbed area. Sword fern can spread via tubers underground. Photographed by J. Baniszewski.
Nephrolepis cordifoia in a disturbed area. Photograph by J. Baniszewski.

Nephrolepis cordifolia is a member of the Nephrolepidaeae family. Also called sword fern, the plant is considered to be a Category I Invasive Plant Species by the FLEPPC (Florida Exotic Plant Pest Council) (MacDonald et al. 2008, Wunderlin and Hansen 2008). It is present throughout Florida, notably Gainesville south since its introduction into the state (MacDonald
et al. 2008).

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Sword fern can spread via tubers underground. Photograph by J. Baniszewski.

 

The tuberous sword fern is often found in wooded areas, such as a hydric hammock community. This woody fern competes with native plants and can often displace them. Reproduction via spores allows the sword fern to reproduce quickly and in high numbers because it can produce thousands of spores year round. These spores can be spread by water or by wind and grow quickly into dense undergrowth (MacDonald et al. 2008).

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Nephrolepsis cordifolia reproduces by spores as well. Sporangia will be present on the underside of fertile fronds. Photograph by J. Baniszewski.
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Pinnate fronds of Nephrolepsis cordifolia has many leaflets per frond. Photograph by J. Baniszewski.

The fern has pinnate fronds that can grow to three feet long and nearly three inches wide. Each frond may have 80-200 leaflets that are oblong to lanceolate shaped (MacDonald et al. 2008). An interesting feature of this fern is that the rachis (frond stem) is overlapped by the frond auricle. Nephrolepsis cordifolia has brown rhizomes with scales and underground tubers. The tubers help to distinguish this species from native ferns (MacDonald et al. 2008).

Management for the fern consists of preventative, cultural, mechanical and chemical methods. There are no biological agents known for Nephrolepsis cordifolia. Preventative, cultural and mechanical measures include removing the plant entirely including underground rhizomes and tubers because these can regrow (MacDonald et al. 2008). Because the fern reproduces by spores, removal of the fern before spores are produces and being careful when disposing of plant remains if spores are present will help with preventative measures. Chemically, the fern can be eliminated using glyphosate containing herbicides. This method should be monitored carefully, using follow up applications if rhizomes and tubers are still present (MacDonald et al. 2008).

Links:

http://plants.ifas.ufl.edu/node/285

http://www.florida.plantatlas.usf.edu/Plant.aspx?id=1824

Nandina domestica (heavenly bamboo)

Nandina domestica, often called heavenly bamboo or just nandina, is on Florida Exotic Plant Council’s Category I invasive species list. It was introduced to the United States in 1804 as an ornamental plant because of its showing fruit and foliage (MacDonald et al. 2008). It has become invasive though because it grows quickly and reproduces both via seeds and vegetatively. It has been known to grow in conservation areas, woodlands and floodplains (MacDonald et al. 2008).

Heavenly bamboo is a woody shrub in the Berberidaceae family. It is evergreen that can grow to eight feet in height and reproduces both by seed and vegetatively from suckers and rhizomes (MacDonald et al. 2008). Leaves are 10 to 20 inches long, alternate, tri-pinnately compound, and turn from red-bronze to green to red again in the fall season.  Leaflets are 1 to 2 inches in length and ovate shaped (MacDonald et al. 2008). Inner bark is yellow. Flowers of Nandina domestica are white and are at the end of stems in panicles. Fruits are red and attract birds and wildlife, which help disperse this plant (MacDonald et al. 2008).

Management strategies include mechanical, preventative and cultural mechanisms. There are no known biological agents for Nandina domestica and limited research about chemical means of management, although glyphosate or triclopyr is likely to work (MacDonald et al. 2008). The best way to manage the N. domestica is to prevent planting and remove existing plants by hand-pulling the weed before seeds are produced. Often, alternative plants are available to plant that are native to Florida (MacDonald et al. 2008).

Links:

http://plants.ifas.ufl.edu/node/281

http://www.florida.plantatlas.usf.edu/Plant.aspx?id=1548

Lygodium japonicum (Japanese climbing fern)

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Lygodium japonicum sterile frond. Photo by EB Sessa.

As its name suggests, this member of the Schizaeaceae family was brought to the United States from Japan in 1932 (MacDonald et al. 2008, Wunderlin and Hansen 2008). It is native to Asia and Australia and was introduced into the United States for ornamental purposes. Since its introduction, it has established itself in the southeastern United States, including Florida where it is considered a Category I noxious weed by FLEPPC (Minogue et al. 2009). Lygodium japonicum can grow in many habitats including full sun, shade, damp and eitherdisturbed or undisturbed areas. The fern forms dense layers that outcompete other plants and prevent native plant seeds from germinating (MacDonald et al. 2008). Because it has below ground rhizomes, it can withstand frost and can therefore establish in regions further north (Minogue et al. 2009).

Lygodium japonicum is a perennial fern that is vine-like and can grow to be 90 feet long. Leaves are arranged oppositely on the vine. Vines and rhizomes are both thin and wiry, but rhizomes are black whereas the vines may be green, orange or black in color (MacDonald et al. 2008). Vines branch off from the underground rhizomes and invade other plants. Fronds are brown to tan colored. Fertile fronds are smaller with marginal projections and have double rowed sporangia. Spores are wind dispersed (MacDonald et al. 2008).

Japanese climbing fern can reproduce by spores or vegetatively. Spores are small, numerous and their longevity allows for the plant to reproduce easily. L. japonicum is also able to self-fertilize (Minogue et al. 2009). Because lower rachis contain sterile pinnae, self-fertilization is more common for the plant as the rachis grows and produces more fertile spores. Vegetatively, L. japonicum grows via its rhizomes underground. With rhizomes a few centimeters below the surface, Japanese climbing fern can then withstand frosts and fire and resprout even if above ground growth is killed (Minogue et al. 2009).

Control of Japanese climbing fern is important in order to maintain natural communities and may include methods of prevention, cultural, chemical or mechanical control. Biological control has been considered, however now naturally occurring agents have been identified as possible control agents for the fern in the United States (Minogue et al. 2009). Neomusotima fuscholinealis feeds on Japanese fern in its native range, but cannot yet be released in the invasive range until further tests ensure proper environmental safety of doing so (Minogue et al. 2009, Pemberton, 2002). Preventative and cultural techniques focus on trying to limit transportation of spore-containing material. It is thought that pine straw harvested on pine plantations may be the source of introducing the fern in to new communities (Minogue et al. 2009, Zeller and Leslie 2004). Chemical treatments are most effective when applying them prior to high spore release, ideally July to October (Minogue et al. 2009).

Links:

http://plants.ifas.ufl.edu/node/639

http://edis.ifas.ufl.edu/fr280

http://www.florida.plantatlas.usf.edu/Plant.aspx?id=1559

http://www.issg.org/database/species/ecology.asp?si=999

 

Leucaena leucocephala (Lead tree)

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Leucaena leucocephala spreads easily and forms dense thickets which outcompete native species. Photograph by J. Baniszewski.
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Leucaena leucocephala (Lead tree)
Photo by J. Baniszewski
Leucaena leucocephala (Lead tree) Photo by J. Baniszewski
Leucaena leucocephala thrives in hammocks. It can be identified by its bipinnate leaves. Photograph by J. Baniszewski.

Leucaena leucocephala is a member of the Fabaceae family and currently is on Florida’s Category II list of invasive species and is considered a noxious weed in Florida (MacDonald et al. 2008, Wunderlin and Hansen 2008). The lead tree is native to Mexico and Central American. and was introduced to Florida in 1898 (MacDonald et al. 2008). L. leucocephala was likely introduced for its use of fodder for cattle or for erosion control. Its wood has also been used for lumber and fuel and the tree was commonly planted as an ornamental to provide shade, control soil erosion or windbreaks (MacDonald et al. 2008).

Leucaena leucocephala (Lead tree) Photo by J. Baniszewski
Seed pods of Leucaena leucocephala are long brown pods that will drop from the tree to allow for easy dispersal of the round, glossy brown seeds inside. Photograph by J. Baniszewski
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Leucaena leucocephala (Lead tree) seed pods.
Photo by J. Baniszewski
Leucaena leucocephala (Lead tree) Photo by J. Baniszewski
Leucaena leucocephala (Lead tree)
Photo by J. Baniszewski

The lead tree is commonly found as shrub or small tree in many communities such as disturbed or cleared areas, coastal or forests communities (MacDonald et al. 2008). Soil acidity (up to pH of 4.1) can be tolerated as well as full sun. It is salt tolerant as well as drought tolerant due to its large roots. Lead tree is known to be able to grow in soils with low fertility, clays, sand, silt and limestone (Langeland et al. 2008). L. leucocephala is fast growing and has high photosynthetic rates thus allowing it to produce a large biomass which can form dense thickets quickly. It may grow up to 30 tons of dry matter per hectare per year. Additionally, surface roots invade the soil and increase competition for other plants (Langeland et al. 2008). It is typically 12-16 feet tall, but can grow to 33 feet and shade native vegetation (MacDonald et al. 2008, Langeland et al. 2008).

Leucaena leucocephala (Lead tree) Photo by J. Baniszewski
Leucaena leucocephala (Lead tree)
Photo by J. Baniszewski
Leucaena leucocephala (Lead tree) Photo by J. Baniszewski
Leucaena leucocephala (Lead tree) seed pod.
Photo by J. Baniszewski
Leucaena leucocephala (Lead tree) Photo by J. Baniszewski
Leucaena leucocephala (Lead tree) along a disturbed fenceline.
Photo by J. Baniszewski

Leaves are ten inches long, bipinnate and are often found with 12 or more pairs of leaflets (MacDonald et al. 2008, Langeland et al. 2008). Leaflets are opposite and about nine millimeters long and three millimeters wide (MacDonald et al. 2008). They are asymmetric, glbabrous, gray-green colored with offset midveins, a pointed tip and rounded base (Langeland et al. 2008)  Flowers contain 10 stamens and are located on branch ends in clusters and turn from white or yellow to brown as they mature (MacDonald et al. 2008, Langeland et al. 2008). There may be 12 – 20 seeds in each pod, which are brown and may range from four to six inches long (MacDonald et al. 2008, Langeland et al. 2008). The actual seeds are also brown, oval, flat, glossy and only a few millimeters long (MacDonald et al. 2008). Seeds are typically dispersed via birds, rodents, and cattle and often germinate after a fire, but are viable for over 10 years (MacDonald et al. 2008, Langeland et al. 2008). The key difference lead tree has from native Florida legumes are the flattened pods and white flower heads. Frosts and fire kill exposed vegetation, but lead tree is able to resprout after a fire (Langeland et al. 2008).

Leucaena leucocephala (Lead tree) Photo by J. Baniszewski
Leucaena leucocephala (Lead tree)
Photo by J. Baniszewski

 

 

 

Management strategies for Leucaena leucocephala are primarily by preventative and cultural strategies. However, biological and chemical means may help to some extent to control this species. Preventative and cultural methods include removing established trees if possible. Removal is recommended before seeds production (MacDonald et al. 2008). Although they do not kill the tree, leucaena psyllid (Heteropsyllacubana), the “jumping lice” can damage lead tree and goats will eat the invasive plant and act as a control agent as well. Triclopyr is a recommended if trying a chemical method of control (MacDonald et al. 2008).

Leucaena leucocephala (Lead tree) Photo by J. Baniszewski
Leucaena leucocephala (Lead tree)
Photo by J. Baniszewski
Leucaena leucocephala (Lead tree) Photo by J. Baniszewski
Leucaena leucocephala (Lead tree)
Photo by J. Baniszewski

Links:

http://plants.ifas.ufl.edu/node/224

http://www.florida.plantatlas.usf.edu/Plant.aspx?id=1397

 

Lantana camara (Lantana)

Lantana camara (Lantana) Photo by J. Baniszewski
Lantana camara (Lantana) Photo by J. Baniszewski
Lantana camara (Lantana) Photo by J. Baniszewski
Lantana camara (Lantana) Photo by J. Baniszewski
Lantana camara (Lantana) Photo by J. Baniszewski
Lantana camara has small flowers that can change color such as orange to red as pictured. Photograph by J. Baniszewski.
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Lantana camara can be found in many different communities throughout Florida, including hammock communities. Photograph by J. Baniszewski.

Lantana camara, or simply just called lantana, was introduced to Florida in 1804 as an ornamental plant from the West Indies (MacDonald et al. 2008). This member of the Verbenaceae family is currently listed as a Category I by the Florida Exotic Pest Plant Council (MacDonald et al. 2008, Wunderlin and Hansen 2008). In the 1700s, Lantana was a highly desired greenhouse specimen and consequently bred into hundreds of cultivars in European markets and from there, introduced worldwide (MacDonald et al. 2008). Lantana camara is similar to L. depressa, Florida’s native species, which is now endangered. After its introduction worldwide, lantana is now also considered invasive internationally in Australia, New Zealand, China as well as in the United States (Florida, Georgia, Texas, California and Hawaii) (MacDonald et al. 2008).

Lantana camara (Lantana) Photo by J. Baniszewski
Fruits of lantana turn from green to black as they ripen. Photograph by J. Baniszewski.
Lantana camara (Lantana) Photo by J. Baniszewski
Lantana camara (Lantana)
Photo by J. Baniszewski

Lantana stalks have been used for paper pulp (wrapping, writing and printing paper), bark has been used as lotion, notably for ulcers caused by leprosy, and leaves have been used to treat swelling and body pains (MacDonald et al. 2008). In addition, alkaloids in lantana can stimulate bowel movements, lower blood pressure and accelerate deep respiration. The plant thrives under numerous conditions of sun, shade, moisture and dry areas and can grow in forests, along roadsides, pastures, and notably citrus groves. Lantana can be problematic economically in Florida citrus groves as well as in pastures where it is toxic to cattle and other livestock (MacDonald et al. 2008).  Lantana camara can inhibit other plants from growing nearby due to allelopathic substances in its roots and shoots (Wunderlin and Hansen 2008).

Lantana camara (Lantana) Photo by J. Baniszewski
Lantana camara (Lantana)
Photo by J. Baniszewski
Lantana camara (Lantana) Photo by J. Baniszewski
Lantana camara (Lantana)
Photo by J. Baniszewski

The shrub is an erect perennial that may grow to be 6 feet tall. Leaves of lantana are rough with a sandpaper-like texture, ovate, and oppositely arranged. They are also aromatic when crushed, serrate and about 6 inches in length and 2.5 inches across (MacDonald et al. 2008). The small flowers are clustered at stem ends and change colors such as white to pink to lavender or yellow to orange to red with the most mature flowers being more darkly colored. Flowers are produced year round and a single plant has potential to produce 12,000 fruits (MacDonald et al. 2008). Fruits are about 0.2 inches in diameter, round and also change color from green to purple and finally black. Lantana can reproduce vegetatively or by seed. Self or cross pollination can occur (MacDonald et al. 2008). One interesting feature of lantana seeds are that the germination rate increases after seeds are passed through animal’s digestive system. Vegetative reproduction occurs when a stem of lantana comes in contact with wet soil and allows root formation to occur (MacDonald et al. 2008).

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Lantana camara (Lantana). Photograph by J. Baniszewski.

Management of lantana is most successful when combining different mechanisms such as burning, chemical applications, manual removal, preventative measures and restoring a natural biodiversity. Prevention mechanisms include removing flower heads which reduces the number of seeds produced or by simply removing the plant from the landscape. Culturally, a habitat with natural biodiversity will help offset potential establishment of lantana (MacDonald et al. 2008). Effective mechanical control may include a plan to use fire or cutting of lantana. Biological control efforts have yields some benefit. In Hawaii, over 20 agents of biological control have been released. Of these, a caterpillar, Hypena strigata, a fly, Ophiomyia lantanae and a lace bug, Teleonemia scrupulusa, have shown the greatest potential. Chemical means often yield regrowth, but  Glyphosate can be used or Fluroxypyr plus aminopyralid can be applied for some effect (MacDonald et al. 2008).

Links:

http://plants.ifas.ufl.edu/node/223

http://www.florida.plantatlas.usf.edu/Plant.aspx?id=1789

Imperata cylindrica (cogongrass)

Imperata cylindrica (Cogongrass) Photo by J. Baniszewski
Imperata cylindrica thriving on the edges of an inundated hammock community. Photograph by J. Baniszewski.

Imperata cylindrica is one of the top ten worst weeds in the world due to its extensive rhizomes, prevalence in poor soils, drought tolerance, genetic plasticity and fire tolerance (Starr et al. 2008). Imperata cylindrical, commonly called cogongrass or japgrass, bloodroot grass and Red Barron, is a member of the Poaceae family (Miller 2003, Wunderlin and Hansen 2008). It is native to Southeast Asia and was introduced into the United States in the early 1900s for the purpose of stabilizing soils (Miller 2003). However, it has since spread throughout the southeastern United States including Florida, Louisiana, Alabama, Mississippi and Georgia (Miller 2003, MacDonald et al. 2008). Originally, cogongrass escaped from a crate of oranges into Mississippi in 1912 (MacDonald et al. 2008). It was then was intentionally introduced as a forage crop into Mississippi and introduced into Florida in the 1930s and 1940s for soil stabilization as well as for forage (MacDonald et al. 2008). In Florida, the weed has thrived and invaded natural communities throughout the state, putting it on Florida’s Noxious Weed List, Florida Prohibited Aquatic Plants List and a Category I on the Florida Exotic Pest Plant Council’s 2011 list (MacDonald et al. 2008).

Imperata cylindrica can grow in a variety of habitats that range from full sun to some shade, including many open forests, coastal lands, riparian zones, scrub, wetlands, ditches, road sides, old fields and pastures (Miller 2003, MacDonald et al. 2008, Starr et al. 2008). Although it is limited by cold temperatures, it can grow on fine sands, heavy clays and low fertility soils (MacDonald et al. 2008). In Asia, cogongrass growth was inhibited if a canopy developed over the grass. However, it is likely that in Florida, cogongrass has developed higher tolerance because it is known to encroach upon old forest areas in the state (MacDonald et al. 2008). Cogongrass is aggressive and has the ability to prevent other native grasses from flourishes because it forms dense mats with branched rhizomes (Miller 2003). These rhizomes can contribute to underground biomass which accounts for over 60% of cogongrass’s total biomass (Starr et al. 2008). Frequent tillage keeps the weed at bay. Further colonization is achieved by wind-dispersed seeds and burning promotes seed dispersion. This is another invasive factor the weed has on natural communities. It is highly flammable and burns very hot posing fire hazards in the locations it has invaded (Miller 2003).

Imperata cylindrica (Cogongrass) Photo by J. Baniszewski
Imperata cylindrica is commonly called cogongrass. Photograph by J. Baniszewski.

The perennial grass is aggressive and can grow to 5 feet tall (Miller 2003). The stem is hidden by long leaves that make up the most of the plants’ height – up to 4 feet (Miller 2003, MacDonald et al. 2008). Because of this architecture with a lack of stem support, the leaves tend to mat together when they reach 3 feet or more. The leaves have yellow-green blades and the midvein is off-center (Miller 2003). Leaves will darken to an orange-brown color as they mature (MacDonald et al. 2008). They are thin, about 0.5 to 1 inch thick and narrow to a sharp tip with slightly serrated margins (Miller 2003, MacDonald et al. 2008). Seeds are typically produced in spring and are dispersed via their long, fluffy, white seedheads (MacDonald et al. 2008). Seeds are brown in color and oblong shaped and are only 1-1.3 mm long allowing them to be easily wind dispersed during May and June via their silver colored husks (Miller 2003). Flowers have white hairs covering paired spikelets and remain on cogongrass year-round in Florida (MacDonald et al. 2008). In addition to seed reproduction, Imperata cylindrical can spread by rhizomes, especially at short distances, which contribute to the grass’ high density. Rhizomes in an established stand of cogongrass can account for 3 tons per acre (MacDonald et al. 2008). Rhizomes are specialized to conserve water and to penetrate into deep soil 4 feet belowground. Additionally, cogongrass’ rhizomes can repel other native plants with allelopathic substances which inhibit other plants from growing nearby (MacDonald et al. 2008).

Imperata cylindrica (Cogongrass) Photo by J. Baniszewski
Imperata cylindrica (Cogongrass)
Photo by J. Baniszewski

To manage cogongrass, prevention is most effective since removal of the rhizomes is difficult. If the grass is present mechanical control by deep plowing the stands or disking several times in a season will exhaust the food reserves and eventually eliminate the weed (MacDonald et al. 2008). Chemical means are limited to only a few herbicides and even more limited depending on the area the grass has invaded. In areas that crops are not present, soil sterilants can be used and are effective, but will also kill any other vegetation and may induce erosion (MacDonald et al. 2008). These chemicals may include prometon (Promitol), tebuthiruon (Spike) or imazzpry (Arsenal). In crop or other vegetated areas, Glyphosate can be applied in several appliactions and Fluazifop (Fusilade DX) can suppress cogongrass to some extent (MacDonald et al. 2008). Periodic burning of cogongrass stands is also recommended to keep vegetation down and induced new aboveground growth which can be more easily treated than if the grass increases rhizome size instead (MacDonald et al. 2008). Burning is ideal during summer when followed by herbicide treatments one to four months later. Finally, after treating for cogongrass, planting crops or other natural plants to provide biodiversity in a natural area will help prevent the weed from recolonizing that area (MacDonald et al. 2008).

Imperata cylindrica (Cogongrass) Photo by J. Baniszewski
Imperata cylindrica (Cogongrass)
Photo by J. Baniszewski

Links:

http://www.srs.fs.usda.gov/fia/manual/Nonnative_Invasive_Plants_of_Southern_Forests.pdf

http://plants.ifas.ufl.edu/node/199

http://www.florida.plantatlas.usf.edu/Plant.aspx?id=1407

http://www.issg.org/database/species/ecology.asp?si=16&fr=1&sts=sss&lang=EN

Dioscorea bulbifera L. (air-potato

 

Dioscorea bulbifera (Air-potato) Photo by J. Baniszewski
Dioscorea bulbifera (Air-potato) is a vine that is commonly found invading hydric hammock communities. Photograph by J. Baniszewski.
Dioscorea bulbifera (Air-potato) Photo by J. Baniszewski
Leaves of Dioscorea bulbifera are heart-shaped (cordate) and dark green. Photograph by J. Baniszewski.

Dioscorea bulbifera was introduced in 1905 as a potential agricultural crop and for its medicinal purposes (Invasive Plant Atlas, MacDonald et al. 2008). It is native to Africa, Asia and Australia (Starr et al. 2008). Brought from Africa, D. bulbifera has expanded from its original introduction in Florida. Currently, it ranges throughout the southeastern United States from Florida and Georgia westward through Texas as well as Hawaii and Puerto Rico (Plants Database). In Florida, it is considered a Category I Invasive Species by FLEEPC and a Florida Noxious Weed (MacDonald et al. 2008).

Air potato is an herbaceous vine that thrives in disturbed areas, hammocks, forest edges among other various communities (Invasive Plant Atlas). It is not able to grow well in coastal habitats due to intolerance for salinity and is not often found in pinelands (Starr et al. 2008).Because it is able to grow eight inches daily, it can quickly form dense clusters and kill other vegetation, even trees by covering and smothering natural plants (Invasive Plant Atlas, MacDonald et al. 2008). In addition to displacing native species, D. bulbifera can alter entire natural communities by altering fire and hydrologic processes. Air-potato is toxic if consumed (MacDonald et al. 2008). However, this invasive vine does have potentially beneficial uses such as its high diosgenin levels which are used for steroidal drug hormones among other chemicals that have been used from air potato for use in contraceptive pills (Starr et al. 2008).

Dioscorea bulbifera (Air-potato) tuber or "potato" Photo by J. Baniszewski
Dioscorea bulbifera (Air-potato) tuber or “potato”.
Photograph by J. Baniszewski
Dioscorea bulbifera (Air-potato) Photo by J. Baniszewski
Dioscorea bulbifera (Air-potato)
Photo by J. Baniszewski

Dioscorea bulbifera is a perennial monocot in the family Dioscoreaceae, also known as the Yam family (Plants Database, MacDonald et al. 2008). The vine is known for its dark-green heart shaped leaves that are arranged alternately (Invasive Plant Atlas). It can grow to be over 18 meters longs and primarily reproduces vegetatively via tubers or bulbils that are potato-like and grow at the axils of the leaves (Invasive Plant Atlas). These tubers are various in size. Large underground tubers may be up to six inches in diameter (MacDonald et al. 2008). D. bulbifera leaf veins start from the leaf base, which is a feature that aids in identifying this vine from others. Although flowers are not commonly present on the vines invading Florida, air-potato does have small flowers about four inches long from leaf axils (MacDonald et al. 2008).

Dioscorea bulbifera (Air-potato) Photo by J. Baniszewski
Dioscorea bulbifera crawling up a tree in a hydric hammock community. Photograph by J. Baniszewski.

Management practices may include preventative measures, cultural, or chemical methods. Air-potato lacks a known biological control agent. Mechanical methods are limited due to the reproduction from small bulbils and damage to other natural vegetation (MacDonald et al. 2008).Spread can be prevented by simply being cautious  and careful when removing vegetative cuttings or debris that may contain tubers or moving landscaping equipment without proper cleaning (MacDonald et al. 2008). It is speculated that air-potato primarily invades disturbed areas by transportation of the tubers after landscaping in one location and moving to another without cleaning equipment or moving soil or other cuttings. Because even very small tubers can sprout, spread by human transportation can be done easily and extra caution should be taken. Additionally, flowing water can easily carry and spread these bulbils (MacDonald et al. 2008).  Chemical methods, like mechanical mechanisms, are hard to apply due to the tuber propagation. Triclopyr or glyphosate (Round-up) is recommended for killing the vegetative growth, but needs to be applied carefully to the vine so as to not kill other vegetation (MacDonald et al. 2008). Gainesville in Alachua county as well as Hernando and Duval counties have been actively removing the vine in city round-ups where volunteers remove the vine and tubers from natural areas. In 2003, Gainesville Parks and Recreation managed to collect 13 tons of air potato and other invasive plants with the help of volunteers (MacDonald et al. 2008).

Dioscorea bulbifera (Air-potato) can easily take over many natural areas once established. Photo by J. Baniszewski
Dioscorea bulbifera (Air-potato) can easily take over many natural areas once established.
Photo by J. Baniszewski
Dioscorea bulbifera (Air-potato) vine with tubers. Photo by J. Baniszewski
Dioscorea bulbifera (Air-potato) vine with tubers.
Photo by J. Baniszewski

Links:

http://www.invasiveplantatlas.org/subject.html?sub=3017

http://plants.usda.gov/core/profile?symbol=DIBU (Note: also shows county distributions of the vine.)

http://plants.ifas.ufl.edu/node/133

http://www.florida.plantatlas.usf.edu/Plant.aspx?id=1726

http://www.issg.org/database/species/ecology.asp?si=1220&fr=1&sts=sss&lang=EN

Broussonetia papyrifera (Paper mulberry)

Broussonetia papyrifera (Paper mulberry) Photo by J. Baniszewski
Broussonetia papyrifera (Paper mulberry)
Photograph by J. Baniszewski

Broussonetia papyrifera is a member of the Moraceae family and is commonly referred to as paper mulberry (MacDonald et al. 2008). It is not native to Florida and although it was brought to the United States as an ornamental tree, it grows vigorously where it has established in natural communities and can displace native plant species (MacDonald et al. 2008). Paper mulberry is native to Japan and Taiwan and has been used to make paper or cloth (MacDonald et al. 2008). Currently, paper mulberry can be found throughout the Southeastern United States from Texas to Florida and northward to Illinois and Massachusetts (MacDonald et al. 2008).

 

Broussonetia papyrifera (Paper mulberry) Photo by J. Baniszewski
Broussonetia papyrifera, commonly called Paper mulberry, is an invasive species commonly found in hydric hammock communities. Photographed by J. Baniszewski.

Paper mulberry is sometimes considered to be a shrub, but is typically described as a tree and can grow to be 30 feet tall (MacDonald et al. 2008). The bark is pale brown in color, smooth and may have slight groove marks. The leaves can be 3 to 10 inches long and are alternate with a pubescent underside (MacDonald et al. 2008). Leaf shape varies with size. Larger leaves are cordate and generally have deep lobes. Smaller leaves are ovate with pointed tips and serrate margins (MacDonald et al. 2008). The tree contains a milky sap that can be seen oozing from the stem if leaves are pulled off or the stem is injured or cut in some way (MacDonald et al. 2008). Because B. papyrifera is deciduous, it has stipule scars, red-brown winter coloration on twigs and pubescent. Paper mulberry can reproduce vegetatively by sprouting or via seed germination (MacDonald et al. 2008).

 

Broussonetia papyrifera (Paper mulberry) Photo by J. Baniszewski
Broussonetia papyrifera growing along a disturbed fence line boarding a hammock community. Photographed by J. Baniszewski.

Broussonetia papyrifera produces male and female flowers on separate trees, making it dioecious (MacDonald et al. 2008). Trees that produce male flowers can be identified by long clusters of flowers produced in catkins. Female flower producing trees have flowers in clusters that are ball-shaped and mature in to fruits. The fruits are aggregated, red, and globose and usually less than an inch in diameter (MacDonald et al. 2008).

 

Paper mulberry, like many non-native species, is an opportunist and is commonly found thriving in disturbed areas (MacDonald et al. 2008). It also favors Florida’s climate and can therefore grow extremely well even in natural communities. After it is established, it can then spread vegetatively or from seeds dispersed by wildlife (MacDonald et al. 2008).

Control of paper mulberry should include preventative, cultural, mechanical, and chemical methods. Preventative and cultural control focus on the idea of the plant being spread by human planting as an ornamental tree. To prevent this, educate homeowners and citizens that paper mulberry is invasive and recommend alternative native plants to add to a landscape (MacDonald et al. 2008). Alternatives that are comparable and native include Acer rubrum (red maple), Celtis occidentalis (hackberry), Nyssa sylvatica (black gum) or Sassafras albidum (sassafras) (MacDonald et al. 2008). Mechanical methods include removing small sized plants by hand or repeatedly cutting larger plants (MacDonald et al. 2008). Bark application of triclopyr ester is effective, although larger trees may need repeated applications. Combining mechanical cutting with herbicide applications will also help to remove the tree (MacDonald et al. 2008).

 

Broussonetia papyrifera (Paper mulberry) Photo by J. Baniszewski
Leaf margins of Broussonetia papyrifera vary considerably from modest lobing (left) to high amounts of lobing (right). Photographs by J. Baniszewski.

Links:

http://plants.ifas.ufl.edu/node/74

http://www.florida.plantatlas.usf.edu/Plant.aspx?id=220