docWeed Identification - Purdue Agriculture
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Weed Identification - Purdue Agriculture
Weed Identification NRCA – 2006 Purdue University Department of Forestry and Natural Resources Plant Characteristics Woody plants Trees-perennial, single main stem or trunk Shrubs-perennial, more than one principal stem, shorter than trees Plant Characteristics Broadleaf Forbs or Herbaceous Plants Non-woody stems that die/dieback each year Broadleaves Netted veins Plant Characteristics Broadleaf Forbs or Herbaceous Plants 2 leaves at germination Coarse root system Plant Characteristics Grasses Narrow upright leaves Parallel veins running length of leaf One leaf at germination Fibrous root system Plant Life Cycles Annual Biennial Perennial Annuals Annuals complete their life cycle in one year. Winter annuals Summer annuals Winter Annual Seeds germinate late summer to early spring, Flower and produce seed in mid-to late spring, and Die the next summer. Wild Geranium Winter Annual Leaves are cut Seedling Summer Annual Seeds germinate in the spring, Flower, produce seeds mid-to late summer, and Die in the fall. Ex-most everything Crabgrass Summer annual 4 part seed structure Flat, spreading Foxtail - Summer Annual Compact seed head bent, Green foxtail straight, Yellow foxtail drooping Giant foxtail Kochia - Summer Annual Multi-branched Small flowers Leaves – stiff and spiny Russian thistle - tumbleweed Annual Round and bushy Reproduces by seed Lambsquarter Annual White patches on interior of leaf Feathery leaves Common Ragweed Summer Annual Giant Ragweed - Summer Annual Leaf – goose foot shape Leaves opposite Marestail - Annual Yellow mustard rosette Water hemp - Annual Biennials Live for two growing seasons. Seeds germinate in spring, summer, or fall of first year. Plants over winter as basal rosette with storage root. After exposure to cold, plants flower and produce seeds in summer of second year. Die in the fall. Sweet Clover Biennial 3 leaflets make up 1 leaf Yellow or white flowers Flowers look like pea plant Wild Carrot Biennial 2nd year – white flower 1st year basal rosette Common Mullein - Biennial 1st year rosette Multiple spikes of yellow flowers Bull thistle - Biennial leaves end in long, sharp spines; Tap-rooted flowerhead bracts tipped with prickles 1st year basal rosettes Musk or Nodding thistle Biennial stems are spiny and winged except below the flower head Large purple flowers droop down or "nod" taprooted thistle leaves are deeply lobed and spiny margined Flowerhead end in a strong, sharp spiny tip Bull thistle biennial larger flower strong prickles spines on leaves Canada thistle perennial -creeping roots smaller flowers weak prickles, no spines on leaves Rosette - Thistle Comparisons Biennials Bull Musk White on edges of leaf Thistle Comparisons Musk Thorns and leaves are near flower head Drooping, flat flower head Bull Thistle Comparisons Musk Canada thistle White midrib Bull Leaf edges wavy Biennial Thorns appear on leaf Perennial Perennials Produce vegetative structure that allows them to live more than two years. Creeping Perennials Overwinters Produces new plants from reproductive structures Most also reproduce from seed Reproductive Structures Rhizomes – horizontal underground stems Tubers - thick underground stems on the ends of rhizomes Bulbs - modified underground leaf tissue Stolons - horizontal above ground stem Creeping roots - underground root modified for food storage and vegetative reproduction, deeper in soil, resistant to control Bermudagrass Perennial – Stolon Stolons – horizontal above ground stems Cattail Perennial – Creeping rhizome Compact brown flower head Long narrow leaves Rhizomes – horizontal underground stems Johnson Grass - Creeping rhizome Reddish flower structure Tall mature plant seedling Reproduces by creeping rhizome - horizontal underground stem Johnson Grass Rhizome Creeping Perennial Simple Perennials Overwinters Reproduce by a perennial root entirely by seed Dandelion - Simple perennial Plantain - Perennial Broadleaf plantain Buckhorn plantain Yellow-star thistle - Annual or Perennial Stems are ridged seedling spines Reproduces from seed Leafy spurge - Creeping perennial Reproduces by seed and extensive creeping roots. The roots can extend as deep as 30 feet and are extremely widespread. Stems show milky sap when cut. Canada thistle - Perennial creeping roots Creeping roots - underground root modified for food storage and vegetative reproduction, deeper in soil, resistant to control Spineless Small flower as compared to others Extensive deep, creeping root system Seedling Knapweed - perennial Common Milkweed Perennial –deep rooted rhizome Flower and seeds Rhizome – horizontal underground stem Curly dock Tap rooted perennial seeds Early stage Mature stage Goldenrod Perennial Flowers in fall Hemp dogbane - Perennial Long seed pods Red Stem has milky sap when cut Opposite branches Horsenettle - Perennial Thorns on leaves and stem Flowers like tomato plant – same family Fruit like tomato plant Pokeweed/pokeberry - Perennial Tall plant Green fruit turning purple St. Johnswort - Perennial Flower with 5 petals Yellow toadflax - Perennial Many leaves along stem Yellow and white flowers – trumpet shaped Stinging Nettle Perennial thorny opposite leaves serrated leaves Vines Ivy-leaf morning-glory Summer annual vine Morning-glory - Annual Blackberry - Woody vines Three leaflets make up a leaf Thorny along stem Fruit Field bindweed Deep tap-rooted perennial White flower Arrowhead shape with slightly rounded tip Japanese honeysuckle Perennial Vine Leaves are opposite Kudzu Perennial vine Leaf with 3 leaflets Poison Ivy Perennial Vine Leaf has 3 leaflets Poisonous all year Poison oak - Perennial vine - Leaf has 3 leaflets Curly edges Locations Poison oak and ivy comparison Poison ivy Poison oak Puncturevine or goathead Annual vine Leaves are opposite and compound. Four to eight pairs of leaflets. Fruit is hard and spiny Breaks into five tacklike sections of seeds It grows low to the ground. Forms a mat with trailing stems, each 1 to 6 feet long and hairy. Virginia creeper - Perennial Grape - Perennial vine Tendrils – climbs by this Trumpet creeper - Perennial vine Compound leaf Woody Black locust Compound leaf with rounded leaflets Two thorns at each leaf Boxelder Green twig Leaf with 3 leaflets Red or slippery elm Serrated edges Off-set base Parallel veins American elm Red elm – scratchy below Elm Siberian elm Siberian elm Slime flux Whitish appearance on bark Opposite branches fruit Flower bud Leaf bud Flowering dogwood Ash Compound leaf Kentucky coffeetree Doubly compound leaf Leaflets have leaflets Sassafras and Mulberry Smooth edges Serrated edges Silver maple 5 lobes 4 3 5 2 Silver beneath Deep sinuses 1 Sugar maple 5 lobes 2 1 3 Shallow sinuses 5 4 Maple Comparison Silver, Red, and Sugar 3 lobes 5 lobes Deep sinuses Shallow sinuses Narrow leaf 5 lobes Shallow sinuses Broad leaf Oak Rounded tips Red oak Bristle or pointed tips White oak Redbud Heart shape leaf Sweetgum Spiny fruit Star shaped leaf Sycamore Tree-of-heaven Large leaf Large stinky twig Numerous bundles of fruit Bracken fern Underground rhizomes Bracken fronds are shaped like triangles Equisetum arvense horsetail Sterile Shaped like a Christmas tree Fertile Equisetum hymale scouring rush sterile fertile
