Invasive Plants of Batiquitos Lagoon A Field Guide created by the Batiquitos Lagoon Foundation Summer Interns of the San Dieguito Academy ECO Club July 24 th, 2012
Table of Contents Iceplant (Carpobrotus edulis)...3 Fennel (Foeniculum vulgare)...4 Pampas Grass (Cortaderia atacamensis)...5 Eucalyptus (Eucalyptus Globulus)...6 Brazilian Pepper (Schinus terebinthifolius)...7 Tamarisk (Tamarix parviflora)...8 Castor Bean (Ricinus communis)...9 Giant Reed (Arundo donax)...10 Artichoke Thistle (Cynara cardunculus)...11 Wild Radish (Raphanus raphanistrum)...12 Black Mustard (Brassica nigra)...13 Canary Island Palm Date Palm Russian Tumbleweed Perennial Pepper Weed
Iceplant (Carpobrotus edulis) Dominates resources including space, water, sunlight, and nutrients Lowers soil ph in loamy sand Suppress growth of seedlings and native shrubs Causes build up of organic matter resulting in the invasion of other non-native plants Shallow, fibrous roots Leaves longer than they are wide Pink, yellow, or yellow-white flowers Flowers terminal and solitary Hand pulling; to prevent resprouting, remove all live shoot segments from contact with soil Use of a tractor; additional use of a brush rake is suggested Use of the herbicide glyphosaate (concentration of 2% or higher); addition of 1% surfactant to break apart cuticle on leaves and use of acidic water is suggested Reproduces both by seed and vegetatively Year round flowering and production of fruit Can produces roots and shoots at every node Active growth year round
Fennel (Foeniculum vulgare ) Erect Perennial herb Four to ten feet tall Feathery leaves Flowers are small and yellow Strong anise scent from stems and leaves Dominates resources including space, water, sunlight, and nutrients Severely alter composition and structure of many plant communities Prevent regrowth of native plant species especially in areas where soil has been disturbed. Disrupt soil to prevent further spread and further disturbances to native species Moderate to heavy grazing Reduce fennel density within dense stands Native to southern Europe and Mediterranean region Reproduces from both root cown and seed Seeds dispersed by water, animals, and vehicles
Pampas Grass (Cortaderia atacamensis) Hand pulling grass seedlings Crowds out other native plants Can reduce aesthetic appeal of the area Outcompetes seedling trees Fire hazard due to dry leaves, leaf bases, and flowering stalks Due to size, can create a physical impediment as well Shiny, stiff, and erect seedling leaves Flowers from late July to September Six to twenty-three feet tall Flower cluster at end of a long stem Stems usually twice as long as flower cluster (found at base) Use of Pulaski, mattock, or shovel for more mature plants Use of a weedeater or chainsaw to expose the crown; remove the crown and roots to prevent resprouting Post-emergence spot treatment with use of glyphosate (concentration 2%); additional use of non-ionic or silicone-based surfactant to enhance foliar penetration is suggested Optional use of graminicide fluazifop and imazapyr (1% concentration) in place of glyphosate Apomictic (no pollen transfer in seed production); asexual reproduction Seed dispersal via wind or humans Germination during spring; ideal temperature of 55-70 degrees F
Eucalyptus (Eucalyptus Globulus) Fragrance from leaves can greatly alter soil composition Leaves are highly flammable Outcompetes native plant species and decreases biodiversity Diminishes amount of wildlife habitat 150 180 feet tall Aromatic Straight-growing tree Bark sheds in long strips, leaving a smooth texture Adult leaves are sickle-shaped that hang vertically and are typically waxy blue Young leaves are oval, bluish green with square stems Fruits are blue-gray, woody, and ribbed Stump grinding - is most effective method to control stump from resprouting as well as eliminating all evidence of tree. 1. Grind all underground portions of stumps to a depth of about two feet 2. Fill resulting craters with soil Prescribed burning: reduce fuels in blue gum stands, and only kills seedlings Chemical control: most effective means of controlling sprouting through application of triclopyr or glyphosate directly to the outer portion of the stump s cut surface at the time of tree felling. Native to Australia, mainly along the east coast of Tasmania Commercial planting boom in California from 1850 to 1900 for lumber and shipbuilding. Propagation by seed is aggressive if ample moisture is available
Brazilian Pepper (Schinus terebinthifolius) Many-stemmed shrub or small tree Branches tangle down to ground level Flowers are small (less than 1/10 of an inch in diameter) with five green tinged, white petals Fruits are abundant, and are bright red and round Narrowly winged stems Rounded, toothed leaflets When leaflets crushed, give off strong smell of turpentine Containment methods: Entire saplings, including the roots, can be pulled by hand when still young Plants that are several feet tall require heavy equipment such as bulldozers in order to be completely eradicated Other methods such as prescribed burning and flooding produced mixed results, either semieradicating the Brazilian pepper tree or inviting growth of other nonnative species
After invasion of an area, creates dense canopy which outcompetes vegetation Produces allelopathic chemicals in the soil that inhibit growth of other plants Tolerant of salt, floods, fire, drought, and resprouts quickly after being cut and wildfires. Native to Argentina, Paraguay, and Brazil Introduced into Florida in 1891 as an ornamental Spreads via small mammals and birds which eat the drupes, then distributing them as they travel Resprouts especially after fire
Tamarisk (Tamarix parviflora) Many-branched shrubs or trees less than 26 feet tall with small scale-like leaves Leaves have salt glands, and salt crystals can often be seen Flowers are small white to deep pink and are densely arranged on racemes Bark is reddish brown with smooth stems less than an inch in diameter Lowers water tables because of high evapotranspiration rate Uses far more water than native riparian plants Soil salinities increase as a result of inputs of salt from glands Leaf litter increases frequency of fire Provides minimal habitat for native species. Containment methods: Root plowing and cutting followed up with herbicidal treatment clear heavy infestations initially Seedlings and small plants can be uprooted by hand Flooding: flooding thickets for one to two years can kill most saltcedar plants Insects and fungi: mealybug and leaf beetle are natural enemies to control saltcedar Herbicides such as imazapyr, triclopyr, and glyphosate are used to combat saltcedar Monoecious (separate male and female flowers on the same plant) Seeds are fertilized then dispersed Used as decoration in homes Prefers mild climates due to cold intolerance (dies if temperature drops below 32 F)
Castor Bean (Ricinus communis) Pulling by hand (for areas with 5-11 lobed, star-shaped leaves up to 3ft long leaves Poisonous oil, Ricin, contained in seeds Flowering but flowers don t have petals Range from green to bright red or purple foliage Plant grows 3-15ft tall Poisonous seeds (several to kill and adult and as little as 1 to kill a child) Toxin, Ricin, is fat not water soluble Displaces other native plants Thrives after a fire Rapid growth May cause allergic reactions moist soil) Foliar-spray (2% glyphosate) to kill mature shrubs; can negatively impact other plants as well Cutting down the plant then applying 25% glyphosate Remove all seeds from the side Follow up monitoring to remove seedlings
Giant Reed (Arundo donax) Hand pulling/cutting; all roots and Forms dense strands Found in riparian areas and wetlands Up to 30ft tall Tapered tips on leaves Hard, hollow stalks about 1in in diameter Tough, fibrous roots Upright feathery plumes (up to 2ft) from March to September above ground vegetation must be removed Cut plants as close to the ground as possible then cover with tarp to prevent sunlight from reaching it Foliar spray (concentration of 2-5% glyphosate); must be preformed after flowering and before summer Apply a stronger concentration of glyphosate directly to the stems after cutting Rapid growth Roots as deep as 10ft Outcompetes native species for resources such as water Have adaptations to prevent Introduced as roofing material and erosion control Ornamental purposes Reproduces vegetativly by means
Artichoke Thistle (Cynara cardunculus) Grows up to 5ft tall Thick, erect, and hairy stems Leaves are silvery/grey-green on top and whitish underneath Leaves form a basal rosette Deep taproot (up to 8ft) Pink, purple, or blue flowers Competes with neighboring vegetation for water and nutrients Form monocultures Plant inhibits the movement of Pull or dig plants out Cut flowers to prevent seed dispersal Grazing by goats may be helpful Foliar spray; larger plants may require 3-4 sprays in one season Brush cutting; every 3 weeks (December-March) and every 4 weeks afterwards until plants are dead Cutting the plant then applying herbicide to the base Abundant seed production Seeds remain viable for up to 7 years Prolonged germination period Resprouts vigorously Spreads primarily via seeds Seeds spread by birds, animals, and water
Wild Radish (Raphanus raphanistrum) Grow up to 3ft or taller Erect with branching stems Has 4-petaled flowers Flowers are pale yellow or while with dark vines Dark red seed pods Seeds are dark, oval, and hard High seed production Long seed dormancy Plants are essentially weeds Seeds in consumed in large quantities may be poisonous Taproot makes removal difficult Hand pulling or use of a Weed wrench Cut plants below the root crow before seed pods develop Mow or brush cutting Foliar spray (concentration of 1% glyphosate); spray before flowering occurs Follow up visits to check for seed germination Seeds viable for at least 5 years, sometimes longer Seeds dispersed by wind, water, or machinery Flowers pollinated by bees and butterflies Native to the Mediterranean
Black Mustard (Brassica nigra) Reach up to 6ft tall Slightly hairy leaves While and fleshy taproot Produces bright yellow, 4- petaled flowers (March to June) Small brown to black seeds Produce chemicals that inhibit germination of other native plants Similar to that of Wild Radish Hand pulling or use of a Weed wrench Cut plants below the root crow before seed pods develop Foliar spray (concentration of 1% glyphosate); spray before flowering occurs Follow up visits to check for seed germination Produces seeds Many small seeds are easily dispersed by wind or water Native to Eurasia
Canary Island Palm