INVASIVE ENGLISH IVY ON THE NORTH COAST

English Ivy, Common Ivy

(Hedera helix L.)



English Ivy is a vine that climbs trees rapidly,
slowing growth. 		Basic English Ivy Ecology

English Ivy is native to Europe and belongs to the Ginseng family.

This invasive species threatens all native forested habitat types as well as urban areas. English Ivy is a trailing, climbing vine, which densely grows along the ground.

It can reach into the upper forest canopy very rapidly. Ivy buries native vegetation, and climbs to weaken and eventually kill mature trees by shading and overweighing.

Ivy roots are vigorous resprouters, meaning that a broken root left in the soil will almost certainly grow a new stem. Ivy vines can grow as large as one foot in diameter and 100 feet in length. Areas dominated by ivy have lower wildlife diversity.

Ivy fruit seems to be preferred mostly by non-native starlings.

English Ivy is a vigourous, dense groundcover.

Mature Ivy leaves and flower.

Identifying Characteristics:


- Woody, evergreen perennial grows as a climbing vine, shrub or groundcover.

- Dark green, leathery spirally arranged leaves are 3-5 lobed with a heart-shaped base.

- Mature Ivy flowers are green-white in fall. Black fruit matures in spring.
trailing vine
3-5 lobed leathery leaves
thick woody vine roots

Additional Resources:
http://tncweeds.ucdavis.edu/moredocs/hedhel02.pdf
http://www.nps.gov/plants/alien/fact/hehe1.htm


INVASIVE SCOTCH BROOM ON THE NORTH COAST
Scotch broom, Common broom, English broom

(Cytisus scoparius)
 
Basic Scotch Broom Ecology

Scotch broom forms dense brush fields especially
in disturbed areas 		Scotch broom is native to southern Europe and northern Africa. Today, Scotch broom invades roadsides, disturbed areas, clearcuts, riparian areas, pastures and native grasslands in the Pacific Northwest. Scotch broom grows best in dry sandy soils in full sunlight.

Scotch broom forms dense brush fields over six feet tall, which crowd out native species, preventing reforestation which destroys wildlife habitat. This invasive hearty woody weed will sprout back vigorously once cut. Scotch broom seeds have hard coats enabling them to survive in the environment for up to 80 years and are successful at wide distribution.

Identifying Characteristics:

- Upright perennial shrub in the Pea family
- Bright yellow flower; seed is green to dark brown legume
- Branches are green and slender, woody stalk
Forms dense brush over 6 ft tall Broom is leafless from late summer
to early spring		 close up of yellow flower
and seed pod

Additional Scotch broom Resources:
http://tncweeds.ucdavis.edu/esadocs/documnts/cytisco.pdf
http://www.na.fs.fed.us/fhp/invasive_plants/weeds/scotch-broom.pdf

INVASIVE BLACKBERRY ON THE NORTH COAST
Himalayan Blackberry

(Rubus discolor, R. procerus, R. fruticosa, R. armeniacus)

Basic Himalayan Blackberry Ecology


Characteristic 5 large, broad leaflets.

Himalayan Blackberry is an invasive species in the Pacific Northwest and is native to Western Europe. It invades all open forest types, especially riparian, disturbed, and moist sites. This invasive grows rapidly and once established, it commonly out competes native vegetation becoming difficult to control.

This non-native can reach a density of 525 canes per square meter. Trailing canes spread up to 20-40 feet, frequently taking root at the tips. Blackberry fails to reproduce well in heavy shade. Seeds can spread considerable distances by streams and rivers and also spreads vigorously by rooting of cane tips.



Identifying Characteristics:

- Dense thickets
- Large, broad leaflets vs. 3 leaflets of native blackberry.


Flowers are white to light pink.
Berry is produced the 2nd
year of growth.

Himalayan blackberry left alone overtakes
native vegetation habitat.

Dense thicket of Himalayan Blackberry.

Additional blackberry resources:
http://tncweeds.ucdavis.edu/moredocs/rubarm01.pdf

INVASIVE KNOTWEED ON THE NORTH COAST

Japanese knotweed (Polygonum cuspidatum, Fallopia japonica, Reynoutria japonica)
Giant knotweed (P. sachalinense)
Himalayan knotweed (P. polystachyum)
Japanese and giant knotweed hybrid (P. X Bohemicum)

Basic Knotweed Ecology

Knotweed is an invasive species found in riparian areas on major streams in the Pacific Northwest. When knotweed is cut or is damaged, it vigorously and rapidly resprouts from root rhizomes. Knotweed dies back to the ground with the first hard frost, and returns each spring from the same root system.

At low elevations, knotweed typically starts growth in April, earlier in warm areas, and as late as June at higher elevations. Even at low elevation, stems from deeply buried roots may emerge as late as July or August. Knotweed grows extremely fast during the spring. Giant knotweed can reach 15 feet (4.5 meters) by June. The slightly shorter Japanese knotweed reaches “only” 10 feet (3 meters) or so. The “dwarf’ Himalayan variety is shorter still, typically reaching 4-6 feet (1.5 - 2 meters).

Knotweed canes.

Knotweed leaves, 3 types.

Identifying Characteristics:

- Hollow, upright, bamboo like stems
- Large, smooth-edged leaves, growing alternate on stems
- Stems often reddish or red-speckled
- Young shoots look similar to red asparagus
- Small white or greenish flowers grow in dense clusters from the leaf joints in July and August
- Hard, dry, brown stems may persist through the winter

Flowering Knotweed branch.
Knotweed infested stream bank.

Additional Knotweed Resources:
http://tncweeds.ucdavis.edu/moredocs/polspp01.pdf
http://www.wsweedscience.org/Slides/2007/14%20Ahrens.pdf