Weed Classification Municipal District #26, Willow Creek, Alberta, Canada

Common Name	Stem	Leaves	Flowers	General Characteristics
Russian Knapweed Scientific Name: (Centaurea repens)	Erect, much branched, becoming hairless with maturity, up to 80 cm tall.	Initially form a rosette, later become alternate, lower leaves toothed to deeply lobed, upper leaves attached directly to stem, smooth to toothed margins.	Small pink to purple flowers clustered in a head to resemble a single flower, solitary at ends of leafy branches, bracts green with whitish tips.	Perennial that spreads by seed and black creeping roots. Commonly confused with diffuse and spotted knapweed. However Russian knapweed is easily distinguished as it has neither spots or spines on the flower head. Reported to exude chemicals which prevents the germination or establishment of neighboring plants.
Canada Thistle Scientific Name: (Cirsium arvense)	Upright, branching near the top, hollow.	Alternate, slightly clasping the stem, variable, from a smooth margin with no spines to irregularly lobed with sharp spines.	Small white to purple flowers clustered into a head resembling a single flower, male (round) and female (flask or urn shaped) flowers found on separate plants, positioned at the ends of branches.	Perennial that spreads by seed and creeping roots. Feathery hairs (pappus) attached to seeds to aid in short distance dispersal.
Common Burdock Scientific Name: (Arctium Minus)	Coarse 3 – 10 feet in second year.	Alternate, large, cordate, thickly hairy, broadest at leaf base, margins toothed or wavy, similar to domestic Rhubarb.	Purple, heads borne in leaf axils or at branch ends. Numerous, clustered, covered with many slender, hooked spines. Achenes gray to brown, mottled, oblong, about Ľ in. long, flattened, slightly curved.	Elevated to noxious weed by the municipality. Found along roadsides, ditches, pastures, and waste area. Burrs become caught in the hair of wild and domestic animals and are thus transferred over great distances. The plant is a biennial. In the second year, flowering and seed production occur from July to September.
Perennial Sow-thistle Scientific Name: (Sonchus arvensis)	Upright, leafy at the base with only a few leaves on the stem, up to 2 m tall	Initially form a rosette, later become alternate, up to 20 cm long, clasp the stem, variable, deeply lobed with spiny edges to smooth leaf margins, color varies from light green to dark green.	Small deep yellow flowers clustered into a head to resemble a single flower, each flower head up to 4 cm in diameter, heads arranged in a loose terminal cluster with approximately 20 heads/plant.	Commonly confused with annual sow-thistle and prickly lettuce. However, it spreads by seed and by extensive underground roots, whereas annual sow-thistle spreads only by seed and has a smaller root system. It is easily distinguished from prickly lettuce as it does not have the distinctive ridge of spines on the midrib on the underside of the leaf that is associated with prickly lettuce. Entire plant contains a milky juice. Feathery hairs (pappus) attached to the seed aid in dispersal.
Ox-eye Daisy Scientific Name: (Chrysanthemum leucanthemum)	Generally unbranched and hairless, up to 1 m tall.	Lower leaves are stalked, up to 15 cm in length, stem leaves progressively smaller and attached directly to the stem, generally hairless, irregularly lobed or wavy margin.	White and yellow, daisy-like, solitary at the ends of long branches, up to 5 cm in diameter.	Perennial that spreads by seed and underground horizontal stems (rhizomes). Commonly confused with scentless chamomile as the flowering heads are very similar. However, the leaves of scentless chamomile are more finely dissected.
Common Tansy Scientific Name: (Tanacetum vulgare)	Several stems in a cluster, branched, up to 2 m tall.	Alternate, deeply divided into toothed segments.	Small yellow flowers grouped into button-like heads, 1 cm wide, 20-200 flower heads/plant arranged in a flat topped cluster.	Aromatic perennial that spreads by seed and short underground horizontal stems (rhizomes). Forms dense patches. Toxic to animals.
Field Bindweed Scientific Name: (Convolvulus arvensis)	Vine-like, twining, prostrate, up to 3 m long.	Alternate, shaped like a slender arrowhead with spreading lobes at the base, on stalks, margins smooth or entire, up to 5 cm long.	Bell to funnel shaped flowers, white to pink, up to 5 cm across, 2 small leaf-like bracts on the stem below the flower.	Perennial weed that spreads rapidly by seed and creeping roots. Forms dense tangled mats or twines around other plants fences, etc. Commonly confused with wild morning glory and wild buckwheat, however it is easily distinguished by the presence of two small leaf-like bracts on the stem below the flower. Also, the absence of a papery sheath (ocrea) at the base of the leaf stalk also distinguishes field bindweed from wild buckwheat.
White Cockle Scientific Name: (Lychnis alba)	Covered in short hairs, upright, swollen at the point where leaves are attached (node), up to 1 m tall.	Opposite, elongate, pointed at the tip, covered in short hairs, smooth leaf margin, up to 10 cm long.	5 deeply notched white petals sometimes giving the appearance of 10 petals, 2 kinds of flowers, one with 10 veins on the lower part of the flower (calyx) which is inflated and produces seed (female), one with 20 veins on the calyx which is slender and produces pollen (male).	Biennial to short-lived perennial that spreads by seed. Commonly confused with night flowering catchfly. However, white cockle is easily distinguished as it does not have sticky leaves or stems.
Bladder Campion Scientific Name: (Silene cucubalus)	Branching, smooth, swollen at point where leaves attach to stem (node), up to 50 cm tall.	Opposite, ovate to elongate, margins generally smooth or entire, without stalks, waxy.	White flowers, in clusters at ends of branches, base of flower (calyx) becomes inflated, veiny and purplish brown as plant matures.	Persistent perennial weed that spreads rapidly by seed and roots branching from a central taproot. Commonly confused with white cockle and night flowering catchfly. However, bladder campion is easily distinguished as it is not covered in hairs.
Knawel Scientific Name: (Scleranthus annuus)	Much branched, swollen at the point where the leaves are attached (node), weak, up to 25 cm tall.	Opposite, attached directly to the stem, needle-like, a few hairs may be present at base of leaf.	Small, green, no petals, sepals fused into a cup-like structure, in small clusters at the base of the upper leaves.	Annual or winter annual that spreads by seed. Possible indicator of acidic soils. commonly confused with corn spurry. However, knawel is easily distinguished as the leaves are opposite and the flowers are green and inconspicuous.
Cleavers Scientific Name: (Galium spurium)	Square, trailing to twining, short bristles, up to 2 m in length.	In whorls (6-8 leaves at one point of attachment), pointed at the tip, rough texture.	Small, 4 white petals, found on small stems in leaf axils.	Annual or winter annual that spreads by seed. Entire plant is covered in bristles which snag like velcro. Fruiting structures are found in pairs.
Hoary Cress Scientific Name: (Cardaria spp.)	Upright with a few branches, lower stem sparsely to densely hairy, upper stem hairless to sparsely hairy and attached directly to the stem, leaf margin smooth to irregularly toothed, up to 8 cm long.	Alternate, lower leaves sparsely to densely hairy, stalked, upper leaves hairless to sparsely hairy and attached directly to the stem, leaf margin smooth to irregularly toothed, up to 8 cm long.	Small, 4 white petals, flowers clustered to alternately arranged at the end of the stem.	Perennial that spreads by seed and creeping roots. Three species of Hoary cress are found in Alberta. Each is named according to the distinct shape of the fruiting structure (pod); heart-podded, lens-podded and globe-podded hoary cress.
Toadflax (Common Yellow) Scientific Name: (Linaria vulgaris)	Often several stems forming dense patches, unbranched to few branches in upper stem, hairless, up to 1 m tall.	Alternate to spirally arranged, numerous, attached directly to the stem, hairless, margins smooth or entire, linear, up to 10 cm long.	Resemble snapdragon, bright yellow with yellow-orange throat, up to 3.5 cm long including the spur extending from the base, alternately arranged along terminal ends of stems.	Perennial that spreads by seed and creeping roots. Commonly confused with leafy spurge when flowers are absent. However, yellow toadflax is easily distinguished by the absence of milky juice in the plant. Also confused with dalmation toadflax, but easily distinguished by the presence of long linear leaves compared to the short broad leaves of dalmation toadflax.
Dalmation Toadflax Scientific Name: (Linaria dalmatica L.)	Often several stems forming dense patches, unbranched to few branches in upper stem, hairless, up to 1 m tall.	Alternate, hairless, broad base, clasp stem.	Resemble snapdragon, bright yellow with yellow-orange throat, up to 3.5 cm long including the spur extending from the base.	Easily distinguished from Common or Yellow Toadflax by the broad leaves. Perennial reproducing by seed and creeping roots.
Leafy Spurge Scientific Name: (Euphorbia esula)	Thickly clustered, hairless, up to 1 m tall.	Alternate to spirally arranged numerous, hairless, attached directly to the stem, narrow, margins smooth or entire, up to 7 cm long.	Greenish-yellow, petals and sepals are absent, clustered with 1 female flower surrounded by several male flowers held within a cup-like structure, subtended by 2 green leaf-like bracts.	Perennial that spreads by seed and creeping roots. Forms dense stands. Commonly confused with cypress spurge. However, leafy spurge is easily distinguished as the plant is taller and leaves are longer, with less branching in the upper part of the plant. All plant parts contain a milky juice which can cause skin irritations.
Cypress Spurge Scientific Name: (Euphorbia cyparissias)	Erect, usually much branched near top of plant, up to 80 cm tall.	Alternate, numerous, small, narrow, linear.	Greenish-yellow, small, clustered at the ends of branches, petals and sepals are absent, subtended by yellowish-green heart shaped bracts which usually turn reddish-green with maturity.	Spreads by seed and an extensive root system. Forms dense stands. Contains a milky juice which is a skin irritant and may also be toxic to animals. Commonly confused with leafy spurge. However, cypress spurge is easily distinguished as the plant and leaves are shorter, and there is more branching in the upper part of the plant.
Stork's Bill Scientific Name: (Erodium cicutarium)	Hairy, trailing up to 2 m long.	Opposite, hairy, finely divided into feathery lobes or toothed segments.	Pink to purple, 5 petals, in clusters.	Annual, winter annual or biennial that spreads by seed. Emerges late and stays green into the fall. Fruit has a long beak ("stork's bill") that coils at maturity and splits open from bottom to top.
Blueweed Scientific Name: (Echium vulgare)	Covered in short stiff hairs, up to 1 m tall.	Initially forms a rosette, later the leaves become alternate, rough texture, hairy.	Bright blue, showy, arranged in one-sided short arching branches.	Biennial to short lived perennial. Commonly found in marginal soils.
Spreading Dogbane Scientific Name: (Apocynum androsaemifolium)	Much branched, up to 60 cm tall.	Opposite, dark green above, lighter green below, broad at the base and narrow towards tip, attached to stem by a short stalk.	White to pink, 5 petals partially joined to form a bell shape, in loose clusters at the ends of branches and in leaf axils.	Perennial that spreads by seed and rhizomes. Exudes a milky juice which can be toxic to animals.
Field Scabious Scientific Name: (Knautia arvensis)	Covered in short stiff hairs, sparsely branched, up to 1.5 m tall.	Opposite, covered in short stiff hairs, lower leaves toothed, middle leaves lobed, upper leaves reduced in size.	Small blue to purple flowers clustered into a head to resemble a single flower, below the head is a ring of narrow green bracts, solitary on the ends of long leafless stems, flower heads up to 4 cm in diameter.	Perennial that spreads by seed.
Hound's Tongue Scientific Name: (Cynoglossum officinale)	Up to 1.5 m tall.	Initially form a rosette, later become alternate, rough textured (like a hound's tongue), hairy, smooth or entire margin, large, up to 30 cm long.	Reddish-purple.	Biennial that spreads by seed. Contains toxic alkaloids that can cause liver damage to grazing animals. Produces numerous bristly seeds that spread by attaching to animals or clothing.
Tall Buttercup Scientific Name: (Ranunculus acris)	Much branched above, up to 90 cm tall.	Lower leaves deeply divided into 3-5 lobes, upper leaves reduced to 3-4 narrow segments, hairy.	Yellow, waxy, 5 petals.	Perennial that spreads by seed. Contain acrid juice that causes pain and inflammation in grazing animals. Common in wet areas and pastures.
Purple Loosestrife Scientific Name: (Lythrum salicaria)	Square, woody, several stems/plant, up to 2.5 m tall.	Opposite to spirally arranged, attached directly to stem, smooth margins.	Numerous, pink to purple, 6 wrinkled petals, attached directly to stem in a dense spike.	Wetland perennial that forms dense brush-like stands. Spreads mainly by seed (2.5 million/plant). Also spreads by underground horizontal stems (rhizomes).
Persian Darnel Scientific Name: (Lolium persicum)	Upright, branching from a reddish base, up to 45 cm tall.	Lower surface glossy, dark green, 6 mm wide.	Clusters of small flowers attached directly to the stem forming a spike, spikelets sitting edgewise on the stem, bristles (awns) extending from each spikelet.	Annual grass that spreads by seed. Fibrous roots.