Horticulture and Invasive Plants Plant Notes

SPOTTER S NETWORK Horticulture and Invasive Plants Plant Notes TITLE SLIDE: HORTICULTURE AND INVASIVE PLANTS BABY S BREATH (Gypsophila paniculata) ID KEY: Distinctive delicate white flowers in clusters Grows to 1 m tall with a deep root system Linear leaves are opposite and hairless, with a prominent mid-vein Seedling plants emerge in early May and develop only one shoot the first year. Habitat: Occurs on a wide variety of habitat but prefers coarse-textured soils; most aggressive in areas with low rainfall. Origin: Europe and Asia Distribution: Okanagan and Kootenay-Boundary regions Other: Baby's breath is used as a garden ornamental and extensively in the floral industry for bouquets. Spread: Seed is the primary mechanism for reproduction with an average plant producing 13,700 seeds. BACHELOR S BUTTONS (Centaurea cyanus) ID KEY: Striking sky-blue (sometimes purple, pink or white) pompom flowers Grows 30 to 90 cm tall Grey-green stems loosely clothed with slender leaves of the same colour. Habitat: Readily invades dry meadows, fields and grasslands. Origin: Europe Distribution: Southern BC Spread: Bachelor s buttons are frequently found as a significant component of wildflower seed mixes. Seedlings grow quickly and produce copious seed. Seeds spread by grazing animals, shoes or clothing, and vehicles and road equipment. 1

BLUEWEED (Echium vulgare) ID KEY: Stems covered in stiff hairs with swollen reddish to black bases where attached to stem that form noticeable flecks. Hairs are painful to the touch. Biennial to short-lived taprooted perennial Basal rosette in first year (spring) Growing to 0.3 to 0.8 meters tall by late June Flowers are initially reddish, later turning deep blue to purple with white centres Flowers are only on the upper sides of short, rough stems Rough hairy leaves which become progressively smaller towards the top of the plant Habitat: Blueweed grows in dry roadsides, disturbed habitats, rocky pastures, and rangelands at low to mid-elevations in British Columbia. Origin: Europe Distribution: Blueweed is in the central and south central areas of the province, it is a major concern in the Kootenay, Okanagan, Thompson, and Cariboo regions. Other: Blueweed invades rangelands, pastures, roadsides and idle areas particularly on coarse, sandy to gravely soils. Blueweed is not usually found in cultivated crops, but can invade rangelands and pastures. Seeds can contaminate clover and other crop seeds. Spread: Blueweed spreads via seed; it produces 500 to 2,000 seeds per plant. Most plants grow near a parent plant, seeds stick to clothing and animals. BUTTERFLY BUSH (Buddleja davidii) 1. ID KEY: Showy, fragrant flowers grow in long, spike-shaped clusters at the ends of the shrub s branches 2. Grows 4 to 5 m tall 3. Deciduous to semi-evergreen shrub 4. Each small, trumpet-shaped flower is purple, with a yellow to orange eye 5. Cultivars can bear flowers ranging from white to many shades of pink and purple 6. Leaves are egg-shaped to lance-shaped and up to 25 cm long. They are green above and grey and woolly below 7. Fruits are sharply pointed, two-segmented capsules 5-6 mm long, with many winged seeds Habitat: Grows in a wide range of habitats, including relatively moist to dry disturbed areas, such as riparian zones, stream- beds, roadsides and rocky slopes. Origin: China Distribution: Infestations occur on southeastern Vancouver Island, in Greater Vancouver and on the Sunshine Coast. Other: Butterfly bush displaces native vegetation, particularly in riparian areas. Attractive to butterflies. 2

Spread: Escaped cultivation in southern BC. Butterfly bush is a prolific seed producer, and a single flower cluster of some varieties can produce over 40,000 seeds. Seeds are dispersed by wind and water, and may remain dormant in the soil for many years. Although butterfly bush does not reproduce vegetatively by underground parts, new plants can grow from cuttings. Plants up to the age of 37 years have been recorded, possibly in garden conditions. COMMON PERIWINKLE (Vinca minor) ID KEY: Shiny, dark green leaves Flowers are violet to blue in colour; bloom in the spring, and intermittently throughout the summer Perennial, evergreen herb with trailing stems Leaves are 2 to 3 cm long, opposite and oval shaped Stems are slender, somewhat woody and green in colour Habitat: Found in sandy to clay soils, and prefers partial shade. Origin: Native to southern Switzerland and North Africa Distribution: Common periwinkle is found primarily in the Lower Mainland of BC. Other: Gardeners value this evergreen plant for its small, violet blue or white flowers and for its shade tolerance. However, periwinkle forms dense mats that suppress many plants and invades moist areas in forested areas and along watercourses. Common periwinkle (Vinca minor) is highly competitive due to its rapid growth and adaptability to many growing conditions. Spread: Reproduces by stolons (runners), with stems rooting at the nodes. COMMON TANSY (Tanacetum vulgare) ID KEY: Common tansy is often confused with tansy ragwort, common tansy has no ray flowers whereas tansy ragwort does Aromatic perennial growing to 0.4 to 1.5 m in height Upright stems are often purplish red and dotted with glands Deeply divided dark green leaves; almost fern-like in appearance Yellow "disc" flowers in cluster at top of plant; no ray flowers Habitat: Common tansy grows at low to mid-elevations along roadsides, stream banks, in disturbed habitats, and pastures; it grows best in full sun and in fertile, well-drained soil. Origin: Europe/Asia Distribution: Common tansy is found in the following regions: Bulkley-Nechako, Central Kootenay, Columbia-Shuswap, East Kootenay, and North Okanagan Regional Districts, and within Greater Vancouver, Fraser Valley, southeast coast of Vancouver Island, Gulf 3

Islands, Sunshine Coast, and Squamish/Pemberton. It is considered a major concern in the Kootenay, Okanagan, and Omineca regions. Other: Undesirable forage and may be toxic to livestock, it can be toxic to humans if large quantities are consumed Spread: Common tansy spreads by seed and roots. Seed can be transported on animals, clothing and vehicles. Seeds can remain viable for up to 25 years; therefore, stopping seed spread is a main concern. SPURGE LAUREL (Daphne laureola) ID KEY: Oblong and clustered evergreen leaves Yellow-green fluted flowers Shrub grows 0.5 to 1.8 m tall Small, black berries Habitat: Adapted to shade and semi-shaded areas. Likely found in the understory of Douglas fir forest. Origin: Europe and northern Africa. Distribution: Woodlands of southwest BC. Other: This evergreen shrub is sold by retailers in some locations in BC, where it is planted as an alternative to dwarf rhododendron. Forms dense thickets and displaces native species and is known to change soil chemistry. The sap is known to cause dermatitis in some people and the leaves, bark, and berries are poisonous. Spread: Reproduces via single-seeded berries and is often spread by birds. ENGLISH HOLLY (Ilex aquifolium) ID KEY: Leaves have a shiny, waxy dark green appearance and are spiny Leaves are alternate on the stem Broadleaf evergreen tree/shrub Grows from 5 to 18 m high Reddish-orange berries are found on female trees in winter Flowers are small and white Bark is green on young plants, smooth and grey on mature plants. Habitat: Thrives in shade or sun in well-drained soil; occurs in mixed deciduous and coniferous forests and along the edges of wetlands and near residential areas. Origin: Europe, Asia, North Africa Distribution: North Vancouver and portions of Vancouver Island. Other: Because of height it casts deep shade that deprives native plants of light, and holly roots effectively out-compete many natives for nutrients and water. The berries are toxic to people if ingested. 4

Spread: Reproduces by producing seeds spread by birds. Small, white flowers attract bees to pollinate them. Female trees must grow within 30 m of a male tree to be pollinated. English holly can also spread by suckering and layering, forming dense thickets. ENGLISH IVY (Hedera helix) ID KEY: Evergreen vine, waxy leaves are 5 to 10 cm long and have three to five deep to shallow lobes, the leaf base is heart shaped. Can grow up to 20 to 30 m high Older growth is woody with strong tendrils which attach to tree bark and solid ground Habitat: Usually found growing up tree trunks and covering the forest floor in closedcanopy forests. Can be found everywhere from shady wood lots to sunny fields. It will grow in wet or dry soils, although it does not thrive in extremely wet conditions. Origin: Europe and Asia Distribution: Southwestern BC, particularly a problem in the Lower Mainland. Other: Ivy can have disastrous effects on all aspects of an ecological system - outcompeting ground cover, shrubs and even mature trees. Thick evergreen ivy mats overwhelm plants on the forest floor, prevent natural seedling succession, debilitate trees, and can damage infrastructure. Spread: Ivy can reproduce both through seeds and vegetatively. In the spring, seeds are eaten and dispersed by birds. Ivy regenerates from cuttings and also produces runners which travel above ground. Plants remain vegetative when their growth is horizontal, but quickly become reproductively mature if allowed to climb. FIELD SCABIOUS (Knautia arvense) ID KEY: large violet to pink, clover-like flowers at the ends of long leafless stalks Perennial Stems are upright and hairy with coarsely toothed, feather-shaped leaves Well developed, woody taproot Habitat: Field scabious is found on roadsides, pastures, and fields at mid-elevations. Origin: Europe escaped ornamental Distribution: Field Scabious is present the Cariboo and Peace agricultural regions and is most troublesome in the Kootenays, Okanagan, Thompson, and Omineca regions. Other: It competes with forage stands and native pastures and is capable of invading undisturbed plant communities. Once established, Field scabious is difficult to eradicate. It is sometimes planted as an ornamental and to attract butterflies. 5

Spread: Each plant can produce up to 2000 seeds that mostly fall near the parent plant but seeds can also be spread by birds and human activities. The seeds remain viable in the soil for many years. HIMALAYAN BALSAM/POLICEMAN'S HELMET (Impatiens glandulifera) ID KEY: Flowers vary from white to pink to reddish and are shaped much like an English policeman's helmet. Annual succulent herb with upright, hollow, much-branched purple-tinged stems Grows 0.6-2.0 m tall Leaves are opposite to whorled, oblong to egg-shaped (elliptical),stalked, and have a serrated margin Habitat: Himalayan balsam grows in riparian areas such as wetlands, river edges and stream banks. Origin: Asia escaped ornamental Distribution: Himalayan balsam is currently found throughout the Lower Mainland, Fraser Valley and Central Kootenay regions of BC. Other: Has a shallow root system and can easily be pulled. Once established, tall Himalayan balsam competes effectively against native plants. In many places it has been known to suffocate native vegetation. Riverside and ditch-bank infestations are spread quickly by mowing operations. Spread: Each plant produces up to 800 seeds; seed capsules "explode" at maturity releasing seeds into rivers and streams which spread far and fast to new locations. Seeds remain viable for up to 18 months. HIMALAYAN BLACKBERRY (Rubus armeniacus) Description: ID KEY: Canes are green/red in colour and grow up to 3 m in height and 12 m in length at maturity and have large hooked or straight prickles Mostly biennial Flowers are petite, white or faint pink with 5 petals, arranged in clusters of 5-20 Flower stalks are prickly, with robust stems (canes) that support large, flattened and hooked or straight prickles Evergreen leaves are predominantly large, rounded or oblong, serrated leaf margin, and generally grouped in fives on first-year canes and threes on second year, flowering canes Fruits are up to 2 cm in diameter, oblong to spherical, black, shiny and hairless. They form on second year canes and ripen from mid-summer to fall Each berry produces numerous seeds that have a hard, impermeable coat Habitat: Preferring rich, well-drained soil, blackberries can grow well in a variety of barren, infertile soil, and are tolerant of periodic flooding or shade. Blackberries grow on 6

disturbed sites, along roadsides and rights-of-ways, in pastures, along river and stream banks, fresh-water wetlands, riparian areas, forest edges, and wooded ravines. Origin: Asia Distribution: They are currently distributed on the Lower Mainland, Sunshine Coast, Fraser Valley, Gulf Islands, central to southern Vancouver Island, Queen Charlotte Islands, the Okanagan, and the West Kootenay areas. Other: Himalayan blackberry out-competes low growing native vegetation through shading and build-up of leaf litter and dead stems. It can prevent the establishment of shade intolerant trees such as Garry oak and ponderosa pine. Blackberries form large, dense, impenetrable thickets that can limit movement of large animals, take over stream channels and stream banks, and reduce sight lines along rights-of-ways. Thickets increase flooding and erosion potential by out-competing deep-rooted native shrubs that would otherwise provide bank stability. Spread: Spread by root and stem fragments, and birds and omnivorous mammals, such as foxes, bears, and coyotes consume berries and disperse seeds. Humans also contribute to blackberry spread by purposefully planting canes. Thickets can produce 7,000-13,000 seeds per square meter, and seeds can remain viable in the soil for several years. KNOTWEEDS (Polygonum spp. and Fallopia spp.) Description: Knotweeds are invasive perennials, with four species found in British Columbia: Japanese Knotweed (Fallopia japonica); Bohemian Knotweed (Fallopia x bohemica); Giant Knotweed (Fallopia sachalenensis); and Himalayan Knotweed (Polygonum polystachyum). ID KEY: A distinguishing feature of Japanese knotweed is the zigzag pattern in which leaves are arranged along the plant s arching stems. Small white-green flowers that grow in showy, plume-like, branched clusters along the stem and leaf joints Hollow stems stand upright and are bamboo-like with reddish-brown speckles and thin, papery sheaths Leaves are heart or triangular-shaped on all species except Himalayan, which are elongated and tapered Stems grow 1-5 m in height at maturity, with leaves 8-10 cm wide and 15 cm long Giant Knotweed leaves are generally twice the size of the other 3 species. Habitat: Knotweeds thrive in roadside ditches, low-lying areas, irrigation canals, and other water drainage systems. They are also found in riparian areas, along stream banks, and in other areas with high soil moisture and areas that are freshly disturbed. Origin: Asia Distribution: Knotweeds occur in the southwest coastal region, the Shuswap, Kitimat, Stikine, Skeena, Columbia, Okanagan, and Kootenay areas, as well as the Queen Charlotte Islands. Additional plants may exist in many gardens in communities across BC. Other: Plants emerge in early spring and produce large leaves that can shade out other plant species. Infestations can dominate stream banks and reduce sight lines along 7

roads, fences, and rights-of-way. Knotweeds threaten biodiversity and disrupt the food chain by reducing available habitat and increasing soil erosion potential. Knotweeds can reduce or eliminate access to water bodies for recreation activities including fishing, swimming, boating, canoeing, and kayaking. Spread: Knotweeds spread rapidly through root systems that may extend from a parent plant up to 20 m laterally and up to a depth of 3 m. Knotweeds are dispersed by human activities or by water to downstream areas, and are of particular concern in riparian areas and areas prone to seasonal high water or flooding. Stream banks are at particular risk as exposed knotweed roots break off and float downstream to form new infestations. MOUNTAIN BLUET (Centaurea montana) ID KEY: Large, bright blue flowers Flowerheads are similar to knapweeds. The disk flowers ("petals") are usually blue but can be white and are solitary on the stems Flowers bloom from late spring to early summer Simple, lance-shaped leaves that have a lightly woolly underside. The whole plant is lightly hairy Tap-rooted perennial herb Grows about 2 feet tall with an equal spread Habitat: Occasionally escapes from cultivation; open, disturbed areas in shrub-steppe, forests, and along roadsides. Origin: Europe Distribution: Infrequent in SW BC, known from S Vancouver Island and the adjacent mainland. Other: Prone to escaping cultivation. May reduce forage opportunities for wildlife and livestock. Spread: Adapted to seeding in dry-land situations and able to self-seed in gardens. ORANGE HAWKWEED (Hieracium aurantiacum) ID KEY: Flowering stalks are covered in stiff black hairs Fibrous rooted perennial with above ground runners Vibrant orange flowers (it is the only hawkweed species with orange flowers) Grows 30 to 60 cm tall Leaves mostly basal Flower stalks are leafless Habitat: grows at low- to mid-elevations, usually in open areas such as pastures, meadows, clearings, roadsides, and disturbed sites. Origin: Europe 8

Distribution: Orange hawkweed is scattered and locally abundant in Central and Southern BC and has isolated infestations on Vancouver Island. It is regarded as a major concern in the Kootenay, Okanagan, Thompson, Cariboo, Omineca, and Peace agricultural regions. Other: Orange hawkweed forms dense mats of rosettes that reduce natural forage and threaten natural diversity. Seeds will mature after plant is cut or pulled so dispose of plants in the garbage. There are 14 species of this plant in BC (both native and introduced). Spread: Seeds are primarily spread by recreationalists. OXEYE DAISY (Leucanthemum vulgare) ID KEY: Oxeye daisy is often confused with the ornamental Shasta daisy, which has larger yellow disk (2-3 cm) and white ray flowers (2-3 cm). Short-lived perennial Daisy-like flowers at the end of course, slender stems, with lower spoon-shaped leaves Central yellow disks grow 1-2 cm wide and white ray flowers 1-2 cm long Can grow up to 1 m in height at maturity Habitat: Occurs at low- to mid-elevations in grasslands and dry to moist forests. Due to its unpleasant taste, most grazers avoid this plant, leaving it to spread easily within grazed grasslands, pastures, and rangelands. Origin: Europe Distribution: Oxeye daisy is present in the Kootenays, Lower Mainland, and Vancouver Island and is of major concern in the Cariboo, Okanagan, Peace River, Thompson, and Omineca regions. Other: Infestations decrease forage for wildlife, decrease local plant biodiversity, and may compromise vegetative ground cover due to its growth form that results in exposed soil. Spread: Oxeye daisy reproduces by seed and underground stems. A single plant produces 26,000 seeds and dispersal from parent plants lead to nearby infestations. PURPLE LOOSESTRIFE (Lythrum salicaria) ID KEY: It has stiff, four-sided stems ending in spikes of showy purple flowers Perennial or woody half-shrub growing 1-3m tall Woody taproot with fibrous branching root system Short, narrow leaves that are stalkless Plants become taller and bushier over the years with a maturing rootstock Sometimes confused with fireweed (Epilobium angustifolium) 9

Habitat: Purple Loosestrife grows in wetlands, stream banks, ditches, irrigation canals, marshes, stream and lake shorelines and shallow ponds at low to mid elevation in BC. Origin: Europe escaped ornamental Distribution: Purple loosestrife occurs in the Fraser Valley and in isolated infestations on Vancouver Island, Okanagan, Cariboo and East and West Kootenay regions. Other: It can form dense stands that reduce plant and animal diversity in wetland ecosystems. Spread: Purple loosestrife reproduces by seed (one plant can produce over 300,000 seeds) which are mainly distributed by water; however, they can also be dispersed by animals and humans. SCOTCH BROOM (Cytisus scoparius) ID KEY: Can be confused with Spanish broom, Spanish broom flowers grow at the tips of stems (crowning the plant), whereas Scotch broom flowers grow along stems Upright, taprooted evergreen shrub in the Legume Family Growing from 1 to 3 m in height Stems are ridged, woody, green to brownish-green and prominently 5-angled Upper leaves are simple and unstalked, lower leaves are stalked and comprised of 3 oval leaflets Pea-like flowers are bright yellow (sometimes with red markings in the middle) Seedpods are flat, brown to black in colour with fine hairs on the margins Habitat: Scotch Broom invades exposed, well-drained mineral soil, and is shadeintolerant. Origin: Europe - escaped ornamental Distribution: Scotch Broom is currently distributed on the Pacific and Atlantic coasts of North America. It is common west of the Coast-Cascade Mountains in southwest BC and is concentrated at the southern end of Vancouver Island. It has also been reported on the Queen Charlotte Islands and in parts of the Kootenays and North Okanagan Shuswap areas. Other: Due to its affinity for light-dominated, disturbed areas, any disturbance activity, such as road or home construction near infested areas, can enhance spread. Scotch Broom invades rangelands, replacing forage plants, and is a serious competitor to conifer seedlings; Douglas fir plantation failures in Oregon and Washington have been credited to infestations of this plant. High density infestations can: Increase wildfire fuel loads, thereby escalating wildfire intensity; and Obstruct site lines on roads, resulting in increased maintenance costs for removal. Dense thickets may be impacting Garry oak woodlands in southwestern BC and limit movement of large animals. Photosynthetic stems enable year-round growth, leading to displacement of native plant species. Spread: Scotch broom spreads by seed and lateral bud growth, and mature plants can produce up to 3500 pods, each containing 5-12 seeds. As seedpods dry they split and 10

spiral, expelling the contained seeds up to 5 m. The plant can also spread to new disturbed areas through seed transport by vehicles and machinery. LEAFY SPURGE (Euphorbia esula) ID KEY: Inconspicuous greenish yellow flowers Perennial with creeping root system Grows to 0.7m tall Leaves spirally arranged up the stalk Habitat: Leafy spurge grows in areas of full sunlight and dry soil but can tolerate a variety of habitats, such as roadsides. It occurs in agricultural areas, natural forests, range/grasslands, rural/disturbed, scrub/shrublands, and urban areas. Origin: Europe/Asia Distribution: There are solated infestations of leafy spurge throughout southern and central BC. Other: Ranked as one of the 100 most invasive species in the world World Conservation Union. The stems contain white milky latex, an irritant to skin and grazing animals. An infestation of leafy spurge eliminates forage-worthy grasses while providing no nutritional value. A large number of Euphorbia species have been introduced to BC gardens, though only a few are problematic, most notably, leafy spurge. Others, such as the myrtle and cypress spurges, are showing invasive tendencies as well. Although these plants may still be popular in gardens, they are (like most Euphobia species), toxic to humans, livestock and wildlife when consumed, or when latex (sap) contacts skin. Spread: Leafy spurge develops an extensive root system that can reach 4.5 m below the soil surface and up to 10 m laterally. It out-competes native vegetation by consuming available water and nutrients, sprouting new plants out of the existing root system, and by shading sunlight and excreting toxins that inhibit growth of surrounding plants. By midsummer, leafy spurge produces high yields of pollen and seed, up to 3,400 pounds of seed per acre. TOADFLAX (COMMON/YELLOW, DALMATION) (Linaria vulgaris, L. genistifolia subsp. dalmatica) ID KEY: Flowers are bright yellow and resemble snapdragons Can be distinguished from Dalmatian toadflax because Dalmatian toadflax has shorter, wider and broad-based leaves clasping the stem Common (Yellow) toadflax is similar but has more linear, pointed leaves that do not clasp the stem Herbaceous perennial Dalmation toadflax has broad, waxy leaves that clasp the stem, grows up to 1.2 m tall 11

Common toadflax grows up to 80 cm tall with soft, lance-shaped leaves Habitat: Found in grasslands, open forests, and on disturbed sites such as roadsides, railroad tracks, cutblocks, cultivated fields and gravel pits Origin: Europe/Asia Distribution: Found in throughout BC but locally abundant in the Okanagan, Similkameen, Thompson, Boundary, East Kootenay, and Cariboo regions Other: Contains a glucoside that is mildly poisonous to cattle. However, the plant is considered unpalatable to cattle and poisonings are rare. Originally were introduced as garden ornamentals and still sold in wildflower mixes Spread: Spreads by seeds and vegetatively by roots. A mature common toadflax plant can produce up to 30,000 seeds annually and seeds remain dormant for up to 10 years. A mature Dalmatian toadflax plant can produce up to 500,000 seeds annually. Seeds remain viable for up to 10 years. YELLOW FLAG-IRIS (Iris pseudacorus) ID KEY: Yellow flag-iris has showy yellow flowers with 3 sepals that curve backward and 3 petals pointing upwards Perennial Leaves fold and clasp the stem at the base in a fan-like fashion, they stand erect or bent at the top, with long sword-like leaves toward the outside of the plant At maturity, plants can reach 1.5 m in height Habitat: Found in wet areas at low- to mid-elevations, growing in ditches, irrigation canals, marshes, stream and lake shorelines and shallow ponds. Origin: Europe/Asia/Africa escaped ornamental Distribution: Currently yellow flag-iris is distributed in BC s southern interior, and has quickly spread throughout the Okanagan valley, lower Similkameen valley, Christina Lake and other isolated sites in the West Kootenays. Other: Dense stands of yellow flag-iris exclude native wetland species, threatening plant and animal diversity. Yellow Flag-iris can sicken livestock if ingested, though it is generally avoided by grazing animals. Contact with the resins can cause skin irritation in humans. Spread: Yellow Flag-iris reproduces quickly through seed dispersal and horizontal root systems, creating thickets in the water like cattails. Up to several hundred flowering plants may be connected rhizomatously under the water, and fragments can form new plants when they break off and drift downstream. Yellow flag-iris is widely sold in nurseries and on the Internet for wet areas and well-mulched soil. While seeds disperse in the wind and water, popularity of the plant in the market exacerbate efforts to contain new infestations. 12

YELLOW ARCHANGEL (Lamium galeobdolon) ID KEY: Serrated, heart-shaped leaves ranging from 2.5 to 8 cm in length Upper sides often have a silver or white pattern and a wrinkly texture Bright yellow flowers between April and June Fast-growing perennial vine Square-shaped, hairy stem The leaf undersides are often lighter green or sometimes purple Habitat: Grows in shaded and open areas; does best in moist shaded sites such as ravines. Origin: Europe, Asia, and North Africa Distribution: Yellow archangel has spread in woodlands, ravines, and riparian areas throughout the Fraser Valley, Vancouver, Vancouver Island and the Gulf Islands. Other: Popular for hanging baskets and as a groundcover. It is widely available, but gardeners should avoid purchasing this plant, as it spreads aggressively in gardens, smothering other plants and depleting soil fertility. Where it has escaped cultivation, usually in urban parklands and woodlands, yellow archangel is difficult to eradicate. Forms a dense blanket of leaves on the forest floor that smothers native plants. Spread: Can produce copious seeds that are dispersed primarily by ants. FLOWERING RUSH (Butomus umbellatus) ALERT SPECIES ID KEY: Umbrella-shaped clusters of upright flowers Each individual flower has 3 petals and 3 sepals that vary in colour from white to a deep pink Leaves are long and narrow with a triangular cross-section and the tips are generally twisted in a spiral shape. Depending on depth, the leaves will be erect when in shallow water and floating when in deeper water. Can grow submersed in water up to 3 m (9.8 ft) deep but grows 1 m (3.3 ft) tall along the shoreline Perennial aquatic shoreline plant Habitat: Grow submersed in water and along shorelines. Origin: Europe/Asia Distribution: Flowering rush has been introduced to a single location in southwest BC, but is not otherwise known to occur in BC. Other: Popular ornamental garden plant. Aggressive and appears to be able to spread and displace native shoreline vegetation due to its thick root system. In areas of abundance where flowering rush is submerged, its dense vegetation can interfere with boating and other recreational activities. It is regarded as one of five invasive alien plants having a major ecological impact on natural ecosystems in Canada and considered a high priority species for eradication in parts of Ontario 13

Spread: Flowering rush spreads from thick, creeping rhizomes and when disturbed, can break to form new plants. The rhizomes also produce many small tubers that can break off to form new plants. In addition, the plants also produce many seeds and sometimes produce tiny bulblets that can be carried by currents to form new plants. Flowering rush tends to colonize areas where new land is exposed as a result of lower water levels. RUSSIAN OLIVE (Elaeagnus angustifolia) ALERT SPECIES ID KEY: Elliptical to lanceolate shaped, dull green to gray coloured leaves Small, fragrant yellow flowers and edible silver berries Large, spiny, perennial deciduous shrub or small growing tree (up to 40ft.) Leaves are alternate and simple, about 1 to 3 inches long and ½ inch wide, distinctly scaly on the top and silvery and scaly on the bottom Buds are quite small, round and silvery-brown and covered with many scales. Branches are silvery, scaly and thorny when the plant is young, and turn a shiny, light brown color when mature. The bark on the Russian olive is at first smooth and gray, and then becomes unevenly rigid and wrinkled later on Berry-like fruit, about ½ inch long, and is yellow when young (turning red when mature), dry and mealy, but sweet and edible In mid-summer, from May to June, shrub blooms fragrant yellow flowers with silvery-gray willow-like leaves Habitat: Usually found in riparian areas, as well as fields and other open areas. Origin: Asia Distribution: Russian olive is known to infest areas around Kamloops, the Okanagan and Lower Mainland of BC; however, they are not currently inventoried for map creation. Other: Displaces native vegetation and exploits the limited water resource where it has escaped cultivation and invaded dry areas. Spread: Berries are sought after by wildlife and contribute to its spread. TAMARISK (Tamarix chinensis, T. ramosissima) ALERT SPECIES ID KEY: Leaves are bright green, diamond shaped, scale-like, alternate, overlapping - strongly resembles cedar foliage Flowers are small, pale pink to white, and borne in finger-like clusters which are 2 to 5 cm long Deciduous, loosely branched shrubs or small trees A few to several stems per plant. Young stems are slender, smooth and reddishbrown the bark on older stems is furrowed. Seed capsules are 3-4 mm long and the petals usually retained on the capsule 14

Habitat: Mainly inhabits the margins of water courses such as rivers, streams, irrigation canals, lakeshores. Origin: Europe, Asia, North Africa Distribution: Known to infest areas of Vancouver Island Other: Tamarisks have escaped cultivation into riparian areas where they send deep roots into the ground that deplete limited water resources. Additionally, stems and leaves secrete salt, which inhibits the growth of other native vegetation. Tamarisks are a major concern, as they are now the dominant riparian species over much of southwestern North America. Spread: They reproduce by seed but can also sprout vegetatively from buried stem or branch pieces. Tamarisk produces massive quantities of tiny seeds which have a short viability period but can germinate quickly in a broad range of conditions. Mature plants can produce hundreds of thousands of seeds that are easily spread by wind and water. GIANT HOGWEED (Heracleum mantegazzianum) ALERT SPECIES ID KEY: Perennial member of the Parsley or Carrot family, resembles our native plant, cow parsnip, grows up to 6 m or more tall Stem is stout, dark reddish in colour, 5-10cm in diameter Leaf stalks are spotted and produce a compound leaf that can expand to 1.5 m across, each leaflet is deeply grooved or divided Stems and stalks are hollow and produce coarse hairs around a blister like pustule Tuberous root-stalks form long-lived buds Small white flowers form together to make an umbrella shaped inflorescence - compound umble The flower head can grow to 1 m in diameter Habitat: Giant hogweed will grow in a variety of habitats but is most frequently found adjacent to streams, creeks, roads, in vacant lots or in rights of ways. It is frequently found in areas that are considered moist to wet. Origin: Asia escaped ornamental Distribution: Known from southern Vancouver Island, the Gulf Islands, and Vancouver. Other: It takes several years to develop a flowering stem. After flowering it sets seed and dies. Additional crowns may form on individual plants. Spread: Giant Hogweed reproduces through seed and perennial buds. Viability of seed can exceed more than seven years. WARNING: The greatest concern from Giant hogweed is human health. The blister like pustules on stems and stalks exude a clear watery sap that sensitizes skin to ultraviolet radiation. Affected areas are subject to severe burns that usually result in blistering and painful dermatitis. Blisters often result in purplish to blackened scars. Giant hogweed's tenacious and invasive nature allows it to readily occupy and crowd out native vegetation. In riparian areas it forms a dense canopy, out-competing native species and causing stream bank erosion. 15