Weed Information: Oxalis stricta (woodsorrel, yellow)
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Oxalis stricta (woodsorrel, yellow)

Family: Oxalidaceae

Description

Leaves with 3 leaflets (like a clover); each leaflet shaped like a heart attached at the narrow end. Leaves often dark purple and with a pleasant, sour taste. The flowers are yellow with 5 petals. This species is common in a variety of usually shady sites. The 1979 Nebraska Weeds mentions Oxalis europaea but this is a synonym for Oxalis stricta despite the fact that it is listed by WSSA.

Characteristics

Flower Color
  • Yellow
Inflorescence Type (How the flowers are arranged on the plant)
  • Axillary cluster
  • Cyme (simple or branched)
  • Panicle
Number of Petals
  • 5 petals
Petal Separation
  • Completely free to base
  • United at base only (<25% length)
Petal Tip
  • Rounded
  • Square
Flower Symmetry
  • Flowers regular
Flower Length (Head length in the Asteraceae)
  • 4 mm (.16 inch)
  • 5 mm (.20 inch)
  • 6 mm (.24 inch)
  • 7 mm (.28 inch)
  • 8 mm (.32 inch)
  • 9 mm (.36 inch)
Flower Width (Head width in the Asteraceae)
  • 8 mm (.32 inch)
  • 9 mm (.36 inch)
  • 1.0 cm (.40 inch)
  • 1.5 cm (.60 inch)
  • 2.0 cm (.80 inch)
Number of Sepals
  • 5 sepals
Sepal Separation
  • Completely free to base
Sepal Tip
  • Pointed
  • Rounded
Flower Sex
  • Bisexual (perfect)
Number of Styles
  • 5 styles
Number of Stamens
  • 10 stamens
Stamens Attached to the Petals
  • Stamens NOT attached to the petals
Stamens Connate (united)
  • Filaments or anthers NOT united
  • Filaments united, monodelphous

Carpel Separation
  • Carpels united (or one)
Number of Carpels
  • 5 carpels
Ovary Position
  • Superior (hypogynous)
Fruit Type
  • Capsule, > 3-celled
Fruit Length at Maturity
  • 1.0 cm (.40 inch)
  • 1.5 cm (.60 inch)
  • 2.0 cm (.80 inch)
  • 2.5 cm (1.0 inch)
Fruit Width at Maturity
  • 2 mm (.08 inch)
  • 3 mm (.12 inch)
  • 4 mm (.16 inch)
  • 5 mm (.20 inch)
Burs
  • Fruit or seed NOT bur-like

Leaf Arrangement
  • Alternate
Leaf Type
  • Trifoliolate (3 leaflets)
Stipules
  • Lacking
Tendrils
  • Tendrils absent
Venation
  • Pinnate
Petiole (leaf stem) Blade Ratio
  • Petiole > 75% 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)
Leaf Width
  • 1 - 2 cm (.40 - .80 inch)
  • 2 - 4 cm (.80 - 1.6 inches)
  • 4 - 10 cm (1.6 - 4.0 inches)
Succulence
  • Succulent
  • Not succulent
Leaf or Leaflet Margin
  • Entire
Leaf or Leaflet Blade Base
  • Acute (cuneate)
Leaf or Leaflet Tip
  • Notched (emarginate, retuse)
Leaf or Leaflet Blade Surface
  • Glabrous (NO hairs)
  • Pubescent
  • Strigose

Milky Juice
  • Juice NOT milky (watery)
Woodiness
  • Herbaceous
Spines or Thorns
  • Spines or Thorns ABSENT
Aromatic (vegetative structures)
  • Not aromatic
Life Cycle
  • Perennial
Growth Habit (while flowering)
  • Prostrate
  • Spreading ascending
Plant Height at Maturity
  • 1 - 5 cm (.40 - 2.0 inches)
  • 5 - 10 cm (2.0 - 4.0 inches)
  • 1 - 2 dm (4.0 - 8.0 inches)
  • 2 - 4 dm (8.0 - 16.0 inches)
Wind Dissemination
  • Not wind disseminated
Moisture Regime
  • Mesic
Chlorophyll
  • Present

Stem Cross Section
  • Round
Flowering Stem Leaves
  • Stem uniformly leafy
Main Stem Branches
  • Main stem branched

Root or Vegetative Propagule
  • Rhizomatous
  • Rooting at the nodes
  • Stoloniferous

US State
  • Alabama
  • Arkansas
  • Connecticut
  • Delaware
  • Florida
  • Georgia
  • Illinois
  • Kansas
  • Kentucky
  • Louisiana
  • Massachusetts
  • Maine
  • Michigan
  • Missouri
  • Mississippi
  • North Carolina
  • New Hampshire
  • New Jersey
  • New York
  • Ohio
  • Pennsylvania
  • South Carolina
  • Tennessee
  • Texas
  • Virginia
  • Wisconsin
  • West Virginia
  • Indiana
  • Maryland
  • Rhode Island
  • Vermont
  • Arizona
  • Colorado
  • Iowa
  • Idaho
  • Minnesota
  • Montana
  • North Dakota
  • New Mexico
  • Oklahoma
  • South Dakota
  • Washington
  • Wyoming
  • Nebraska
Canadian Province or Territory
  • British Columbia
  • New Brunswick
  • Nova Scotia
  • Ontario
  • Prince Edward Island
  • Quebec
  • Manitoba
  • Newfoundland
  • Saskatchewan
Other
  • District of Columbia

  • Common Weeds of the United States, 1971 (ISBN 0-486-20504-5) See page: 240
  • Field Guide To The Common Weeds Of Kansas, 1983 (ISBN 0-7006-0233-X) See page: 78
  • Gilkey`s Weeds of the Pacific Northwest, 1980 (ISBN 0-88246-039-0) See page: 177
  • How to Know the Weeds, 1972, (ISBN# 0-697-04880-2) See page: 104
  • Identification Guide to the Weeds of Quebec, 1999 (ISBN# 2-89457-174-7) See page: 118
  • Identifying Seedling and Mature Weeds (Southeastern US) 1980 North Carolina Agricultural Research Service, Bulletin #461 See page: 118
  • Manual of Ohio Weeds, 1931 Ohio Ag. Exp. Station Bull. # 475, See page: 44
  • Nebraska Weeds, 1979 Nebraska Dept. of Ag., Lincoln NE, See page: 95
  • Ontario Weeds, 1992 Agdex 640, Publication #505 See page: 122
  • Some Weedy Plants of North Carolina, 1955 North Carolina Ag. Ext. Circular # 390, See page: 32
  • South Dakota Weeds, 1967 South Dakota State University, See page: 114
  • South Dakota Weeds 2002 South Dakota Dept. of Ag. 523 E. Capitol, Foss Bldg. Pierre, South Dakota 57501 See page: 105
  • S.W.S.S. Weed ID Guide, 1993 Section Number and Five letter code: 11 OXAST
  • Weed Seeds of the Great Plains, 1993 University of Kansas# 92-125-B ISBN# 0-7006-0651-3 See index #: 136
  • Weeds, 1955 (1980) Walter Conrad Muenscher, ISBN# 0-8014-1266-8 See page: 292
  • Weeds of Arkansas 1981 (MP 169-5M-3-81) See page: 48
  • Weeds of Kentucky and Adjacent States, 1991 (ISBN 0-8131-1743-7) See page: 130
  • Weeds of Southern Turfgrasses, 1992 Univ. of Florida, Gainesville Publication # SP-79, See page: 158
  • Weeds of the Midwestern United States & Central Canada, University of Georgia 2010, ISBN#0-8203-3506-1 See page: 251
  • Weeds of the North Central States, 1981 Univ. of Illinois, Urbana - Champaign Bulletin # 772, See page: 111
  • Weeds of the Northeast, 1956, Univ. of Delaware Field Manual #1 See species #: 328, 329
  • Weeds of the Northeast, 1997 Cornell University ISBN# 0-8014-8334-4 See page: 266,370
  • Weeds of the Northern United States and Canada, 1964 Montgomery See page: 101
  • Weeds of the South, University of Georgia 2009, ISBN#0-8203-3046-9 See page: 245
  • Weeds of the Southern United States, 1975, North Carolina Ag. Extension Circular #599 See page: 33
  • Weeds of the United States and Their Control, Lorenzi 1987, ISBN# 0-442-25884-4 See page: 186
  • Weeds of the West, 1992 (ISBN 0941570-13-4) See page: 399
  • Weeds of the West, 2000 (ISBN 0941570-13-4) See page: 399
  • Weeds of Utah, 1971 UAES Special Report 21, See page: 54
  • Listed as a `Weed` by the Biota of North America Program, 2008 x
  • Listed in the WSSA Composite List of Weeds X
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