Flower Color

• Yellow

Inflorescence Type (How the flowers are arranged on the plant)

• Cyme (simple or branched)
• Head
• Solitary, terminal

Number of Petals

• 0 (no petals)
• 5 petals
• more than 10 petals

Petal Separation

• Completely free to base
• United > 75% of length

Petal Tip

• Pointed

Flower Symmetry

• Flowers regular

Flower Length (Head length in the Asteraceae)

• 1.0 cm (.40 inch)
• 1.5 cm (.6 inch)
• 2.0 cm (.8 inch)
• 2.5 cm (1.0 inch)

Flower Width (Head width in the Asteraceae)

• 1.0 cm (.40 inch)
• 1.5 cm (.60 inch)
• 2.0 cm (.80 inch)
• 2.5 cm (1.0 inch)

Number of Sepals

• sepals lacking
• more than 10 sepals

Sepal Separation

• Completely free to base

Sepal Tip

• Pointed
• Spine-like

Flower Sex

• Bisexual (perfect)

Number of Styles

• 1 style

Number of Stamens

• 5 stamens

Stamens Attached to the Petals

• Stamens attached to the petals

Stamens Connate (united)

• Anthers united, syngynoecious

Carpel Separation

• Carpels united (or one)

Number of Carpels

• 1 carpel

Ovary Position

• Inferior (epigynous)

Fruit Type

• Achene

Fruit Length at Maturity

• 2 mm (.08 inch)
• 3 mm (.12 inch)
• 4 mm (.16 inch)

Fruit Width at Maturity

• 1 mm (.04 inch) or less
• 2 mm (.08 inch)
• 3 mm (.12 inch)

Burs

• Fruit or seed NOT bur-like

Leaf Arrangement

• Alternate

Leaf Type

• Simple (including lobed leaves)

Stipules

• Lacking

Tendrils

• Tendrils absent

Venation

• Pinnate

Petiole (leaf stem) Blade Ratio

• Petiole absent (leaf sessile)
• Petiole < 25% total length

Leaf Length (blade PLUS petiole)

• 1 - 2 cm (.40 - .80 inch)
• 2 - 4 cm (.80 - 1.60 inches)
• 4 - 10 cm (1.60 - 4.0 inches)
• 1 - 2 dm (4.0 - 8.0 inches)

Leaf Width

• 5 - 10 mm (.20 - .40 inch)
• 1 - 2 cm (.40 - .80 inch)
• 2 - 4 cm (.80 - 1.6 inches)
• 4 - 10 cm (1.6 - 4.0 inches)

Leaf Shape (simple leaves only)

• Lanceolate
• Linear or filiform
• Lyrate
• Pinnately lobed

Leaf or Leaflet Margin

• Entire
• Lobed
• Parted

Leaf or Leaflet Blade Base

• Acuminate (attenuate)
• Clasping

Leaf or Leaflet Tip

• Acuminate (attenuate)
• Acute

Leaf or Leaflet Blade Surface

• Floccose
• Puberulent
• Pubescent
• Tomentose

Succulence

• Not succulent

Milky Juice

• Juice NOT milky (watery)

Woodiness

• Herbaceous

Spines or Thorns

• Spines or Thorns ABSENT
• Spines on flowers or fruits only

Aromatic (vegetative structures)

• Not aromatic

Life Cycle

• Annual

Growth Habit (while flowering)

• Erect, columnar (narrow)
• Erect, spherical (bushy)

Plant Height at Maturity

• 1 - 2 dm (4.0 - 8.0 inches)
• 2 - 4 dm (8.0 - 16.0 inches)
• 4 - 6 dm (1.3 - 2.0 feet)
• 6 - 8 dm (2.0 - 2.6 feet)
• 8 - 10 dm (2.6 - 3.3 feet)
• 1 - 1.5 meters (3.3 - 5.0 feet)

Wind Dissemination

• Not wind disseminated
• Fruit, seed, or spore wind borne

Moisture Regime

• Mesic
• Arid

Chlorophyll

• Present

Stem Cross Section

• Round
• Winged

Flowering Stem Leaves

• Stem leaves greatly reduced
• Stem uniformly leafy

Main Stem Branches

• Main stem unbranched
• Main stem branched

Root or Vegetative Propagule

• Tap Root

US State

• Connecticut
• Florida
• Illinois
• Kansas
• Kentucky
• Massachusetts
• Michigan
• Missouri
• North Carolina
• New Hampshire
• New Jersey
• New York
• Ohio
• Pennsylvania
• South Carolina
• Tennessee
• Texas
• Virginia
• Wisconsin
• West Virginia
• Indiana
• Maryland
• Rhode Island
• Arizona
• California
• Colorado
• Iowa
• Idaho
• Minnesota
• Montana
• North Dakota
• New Mexico
• Nevada
• Oklahoma
• Oregon
• South Dakota
• Utah
• Washington
• Wyoming
• Nebraska

Canadian Province or Territory

• British Columbia
• Ontario
• Alberta
• Manitoba
• Saskatchewan

• An Illustrated Guide To Arizona Weeds, 1972 (ISBN 0-8165-0288-9) 338 pages. See page: 282
• California Growers Weed Identification Handbook, 1968 - 1998 University of California Publication # 4030-1, See page: 31
• Common Weeds of the Canadian Prairies, 1963 (Cat# A53-1136-1) See page: 29
• Common Weeds of the United States, 1971 (ISBN 0-486-20504-5) See page: 386
• Common Weed Seedlings of the United States and Canada, 1978 Coop Ext. Univ. of Georgia, Athens, See page: 11
• Gilkey`s Weeds of the Pacific Northwest, 1980 (ISBN 0-88246-039-0) See page: 335
• How to Know the Weeds, 1972, (ISBN# 0-697-04880-2) See page: 174
• Manual of Ohio Weeds, 1931 Ohio Ag. Exp. Station Bull. # 475, See page: 108
• Northwest Weeds, 1990 (ISBN 0-87842-249-8) See page: 145
• Selected Weeds of Oregon, 1985 and 1989 Supplement (s) Oregon State Dept. of Agriculture, See page: 78
• South Dakota Weeds 2002 South Dakota Dept. of Ag. 523 E. Capitol, Foss Bldg. Pierre, South Dakota 57501 See page: 219
• S.W.S.S. Weed ID Guide, 1993 Section Number and Five letter code: 13 CENSO
• Weeds, 1955 (1980) Walter Conrad Muenscher, ISBN# 0-8014-1266-8 See page: 443, 444
• Weeds, A Golden Guide, 1972 ISBN#0-307-24353-2 See page: 147
• Weeds and Poisonous Plants of Wyoming and Utah 1987 (ISBN 0-941570-06-1) See page: 168
• Weeds of California, 1970, State of California Publications and Documents. See page: 433, 434
• Weeds of California and other Western States, 2007 (ISBN 13: 978-1-879906-69-3) See Page: 250
• Weeds of Colorado, 1990 Cooperative Extension, Colorado State Univ. Bulletin 521A, See page: 176
• Weeds of Eastern Washington and Adjacent Areas, 1972 (LOC 72-83635) See page: 284
• Weeds of Nebraska and the Great Plains, 1994 (ISBN 0939870-00-4) See page: 103
• Weeds of the Midwestern United States & Central Canada, University of Georgia 2010, ISBN#0-8203-3506-1 See page: 76
• Weeds of the Northern U.S, and Canada, 1999 Royer and Dickinson, (ISBN# 1-55105-221-0) See page: 29
• Weeds of the South, University of Georgia 2009, ISBN#0-8203-3046-9 See page: 62
• Weeds of the West, 1992 (ISBN 0941570-13-4) See page: 94
• Weeds of the West, 2000 (ISBN 0941570-13-4) See page: 96
• Weeds of Utah, 1971 UAES Special Report 21, See page: 94
• Listed as a `Weed` by the Biota of North America Program, 2008 X
• Listed in the WSSA Composite List of Weeds X
• Centaurea stoebe ssp. micranthos / Asteraceae / knapweed, spotted
• The Biology of Canadian Weeds: Canadian Journal of Plant Science Vol54 Pg 687
• Common Weeds of Canada, Mulligan 1987 (ISBN 0-910053-59-9) See page: 105
• Common Weeds of the Canadian Prairies, 1963 (Cat# A53-1136-1) See page: 29
• Common Weeds of the United States, 1971 (ISBN 0-486-20504-5) See page: 382
• Gilkey`s Weeds of the Pacific Northwest, 1980 (ISBN 0-88246-039-0) See page: 333
• How to Know the Weeds, 1972, (ISBN# 0-697-04880-2) See page: 175
• More Turfgrass and Related Weeds: Beyond the Color Atlas, 2011 Clemson University Publishing ISBN# 978-0-9798777-5-9 See Page: 165
• Northwest Weeds, 1990 (ISBN 0-87842-249-8) See page: 149
• Ontario Weeds, 1992 Agdex 640, Publication #505 See page: 243
• Pennsylvania Field Guide, Common Invasive Plants in Riparian Areas, 2004 See Page: 13
• Selected Weeds of Oregon, 1985 and 1989 Supplement (s) Oregon State Dept. of Agriculture, See page: 75
• Some Important Michigan Weeds, 1951 Mich. Ag. Exp. Station Bulletin #304, See page: 213
• South Dakota Weeds, 1967 South Dakota State University, See page: 206
• South Dakota Weeds 2002 South Dakota Dept. of Ag. 523 E. Capitol, Foss Bldg. Pierre, South Dakota 57501 See page: 217
• S.W.S.S. Weed ID Guide, 1993 Section Number and Five letter code: 13 CENMA
• Weed Seeds of the Great Plains, 1993 University of Kansas# 92-125-B ISBN# 0-7006-0651-3 See index #: 204
• Weeds, 1955 (1980) Walter Conrad Muenscher, ISBN# 0-8014-1266-8 See page: 442, 443
• Weeds, A Golden Guide, 1972 ISBN#0-307-24353-2 See page: 147
• Weeds and Poisonous Plants of Wyoming and Utah 1987 (ISBN 0-941570-06-1) See page: 164
• Weeds of Alberta, 1983 Alberta Environmental Centre Agdex 640-4, See page: 183
• Weeds of California and other Western States, 2007 (ISBN 13: 978-1-879906-69-3) See Page: 235
• Weeds of Canada, 1970 Canada Dept. of Ag., Pub. # 948, See page: 193
• Weeds of Eastern Washington and Adjacent Areas, 1972 (LOC 72-83635) See page: 280
• Weeds of Kentucky and Adjacent States, 1991 (ISBN 0-8131-1743-7) See page: 170
• Weeds of Nebraska and the Great Plains, 1994 (ISBN 0939870-00-4) See page: 102
• Weeds of the Midwestern United States & Central Canada, University of Georgia 2010, ISBN#0-8203-3506-1 See page: 73
• Weeds of the North Central States, 1981 Univ. of Illinois, Urbana - Champaign Bulletin # 772, See page: 194
• Weeds of the Northeast, 1956, Univ. of Delaware Field Manual #1 See species #: 306
• Weeds of the Northeast, 1997 Cornell University ISBN# 0-8014-8334-4 See page: 126
• Weeds of the Northern United States and Canada, 1964 Montgomery See page: 177
• Weeds of the Northern U.S, and Canada, 1999 Royer and Dickinson, (ISBN# 1-55105-221-0) See page: 28 - 29
• Weeds of the South, University of Georgia 2009, ISBN#0-8203-3046-9 See page: 60
• Weeds of the West, 1992 (ISBN 0941570-13-4) See page: 88
• Weeds of the West, 2000 (ISBN 0941570-13-4) See page: 92
• Listed as a `Weed` by the Biota of North America Program, 2008 X
• Listed in the WSSA Composite List of Weeds X
• Centaurea virgata ssp. squarrosa / Asteraceae / knapweed, squarrose
• Weeds of California and other Western States, 2007 (ISBN 13: 978-1-879906-69-3) See Page: 235
• Weeds of the West, 1992 (ISBN 0941570-13-4) See page: 96
• Weeds of the West, 2000 (ISBN 0941570-13-4) See page: 98
• Weeds of Utah, 1971 UAES Special Report 21, See page: 94
• Listed as a `Weed` by the Biota of North America Program, 2008 X
• Listed in the WSSA Composite List of Weeds X