Weed Spotter!


Alternate leaves  Arrangement of leaves one at a time along a stem at the nodes.
Prostrate  Growing flat along the ground.
Nodes  Divisions of a plant stem: nodes hold buds (which grow into leaves) and internodes are the distance between nodes.
Axil  Angle between the upper side of a leaf and its supporting stem.

Carolina geranium –– Geranium carolinianum
Leaves are 1-3” across and alternate with deeply cut finger-like divisions. Stems are erect and branch at the base, reaching heights of 20”. Flowers are small, pale pink to lavender with five petals, and occur either singly or in loose clusters at the tips of stems and branches.
Crabgrass –– Digitaria sanguinalis
Stems are many-branched and upright or prostrate, often with purple stems, forming a mat. Crabgrass flowers occur stalk ends with 3 to 13 purplish finger-like spikes up to 6” long.

Creeping charlie –– Clechoma hederacea
Perennial with vigorous, above-ground, square stems and small purple tube-like flowers in spring. Plant remains green year round. Leaves arranged opposite each other, are rounded with scalloped edges.

Photo credits:
Top: Creeping charlie in mulch, loonyhiker
Bottom: Creeping charlie flower, zen Sutherland

Curly dock –– Rumex crispus
Lance-shaped leaves are alternate along stout stems forming a rosette. Mature curly dock stands erect and grows 2-5’. Fruits and stems turn a distinctive rusty brown.

Photo credits:
Top: Young plant
Bottom: Mature plant and seed heads

Dandelion –– Taraxacum
The first true leaf is round to oval and about 3/8” long. Leaf margins have a few small teeth that point back toward the base of the leaf. More mature leaves are elongated with toothed margins and rosette arrangement typical of the mature plant. Stems are smooth. Flowers begin on a short stem near the ground, the stem quickly elongates, lifting the bud above the leaves.

Photo credits:
Top: Young dandelion
Bottom: Mature dandelion, John and Anni Winings

Henbit –– Lamium amplexicaule
Opposite leaves are broadly egg-shaped with toothed margins and prominent veins on the underside. Can grow to 16”. Stems are sparsely hairy, green to purple, and square. Flowers are reddish purple with darker coloring on lower petals arranged in whorls in the upper leaves.

Photo credit:
Bottom: Mature henbit, Jerry Oldenettel

Hoary alyssum –– Berteroa incana
Short lived perennial that grows 1-3’ tall. Stems are tall, upright and grayish-green with rough hairs. Leaves are oblong and lobed alternating along the stem. Small while flowers appear in clusters at the top of the stem.

Photo credits:
Top: Young hoary alyssum
Bottom: Mature hoary alyssum, Matt Lavin

Lamb’s quarters –– Chenopodium album
Alternately-toothed leaves 1-3” long with a white mealy coating on the underside. Stem is smooth with red or light green stripes and arises from a taproot. Flowers are small, green, without petals on the ends of branches and in the axils of stems. Plants can grow up to 4’.

Photo credits:
Middle: Mature lambs quarters, Jerry Oldenettel
Bottom: Lamb’s quarters flower head, Jerry Oldenettel

Nutsedge –– Cyperus esculentus
Leaves emerge from plant base, grass-like and light yellow-green, 1/8 to ½” wide, up to 3’ long. Flowers are burr-like occurring at end of a stout, triangular, yellow-green stem.

Photo credits:
Top: Nutsedge seed head
Bottom: Young nutsedge, kimberlysteinmann

Pigweed –– Amaranthus blitoides
Spear-shaped, dull green leaves covered with dense, coarse hairs, prostrate growth habit. Red or light green stripes run the length of the main stem.

Photo credits:
Middle: Pigweed seed head, Doug Waylett
Bottom: Pigweed mature plant, pawpaw67

Plantain –– Plantago major
A low growing perennial with broad, oval leaves that quickly narrow to a thick leaf stem toward the plant base. Flower spikes are 6’12” tall and grow from the center of the plant.

Photo credits:
Top: Broadleaf plantain, F.D. Richards
Bottom: Broadleaf plantain, Nikol Lohr

Purslane –– Portulaca oleracea
Alternate, oval, fleshy leaves forming near branch ends in five-petal clusters. Purple to red succulent, smooth, fleshy stems grow prostrate and form mats. Small, yellow flowers also cluster at branch ends.

Photo credits:
Top: Young purslane
Middle: Mature purslane, Alyss
Bottom: Purslane flowers, Ed Ogle

Quackgrass –– Agropyron repens
A perennial grass that grows well in spring and fall. Often blueish in color and forms clusters. Leaves are 2-12” long and ¼-3/8” wide, often appearing slightly twisted as they unfurl from the shoot. Flower heads are spike-like and the plant spreads through underground rhizomes.

Photo credits:
Top: Quckgrass mature flower head, Andrey Zharkikh
Bottom: Quackgrass, Matt Lavin

Ragweed –– Ambrosia artemisiifolia
Emerges early in spring with deeply dissected leaves arranged oppositely when young, and alternately in older parts of the plant. Leaves are hairy on both surfaces.

Photo credits:
Top: Ragweed, F.D. Richards
Middle: Giant ragweed, Friends of Prairie Learning Center and Neal Smith’s NWR photostream
Bottom: Ragweed flower head, Dendroica cerulea

Smartweed –– Persicaria pensylvanica
Leaves are smooth with sparse hairs, sometimes marked with a purple blotch. Vertical multi-branched stems, green or red in color, are jointed at the nodes. Small white to pink flowers grow singly on short stems, forming clusters and branching from a common stem.

Photo credits:
Top: Young smartweed, Kristin
Bottom: Smartweed flower, eyeweed
Spurge –– Euphorbia maculate
Spurge has prostrate stems that can grow up to 20”. Branches alternate along the stem. New leaves are typically hairy, especially lower leaf surfaces. Leaves are oblong to egg-shaped, about 1/6 to 2/3” long, often marked with a dark, reddish spot found midway down the center of the leaf vein. Flowers are grouped in small flower-like cups and surrounded by white to pink petal appendages.

Thistle –– Cirsium arvense
First two leaves emerge oval, thick, dull green and united at the base forming a shallow cup. Subsequent leaves are egg-shaped and have bristly hairs on the upper and lower surfaces. Stems are erect, green and grooved with many branches, growing up to 4’. Flowers consist of as many as 100 purple tubular flowers clustered onto a head and surrounded by scale-like leaves (bracts).

Photo credit:
Top: Young thistle, lostinfog

Wild violet –– Viola papilionacea
Low growing perennial that grows in patches and spreads by underground rhizomes. Leaves are broad, heart-shaped and deep to bright green. Has small flowers that bloom May-June and can be nearly white to deep purple.

Photo credits:
Top: Young wild violet, Joan
Bottom: Wild violet flowers, Paul Cooper

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Visit University of Minnesota Extension’s Weed ID page!