Weed Information: Lepidium draba (cress, hoary)
Back to Plant List

Lepidium draba (cress, hoary)

Family: Brassicaceae

Description

The genus Cardaria has recently been merged into the genus Lepidium, so the scientific nomenclature here will not be in agreement with many existing weed reference books. There are 3 species of Lepidium referred to as various types of `whitetop.` They are all rhizomatous perennials with flat topped clusters of white flowers that form somewhat inflated fruits. They are distinguished as follows: Sepals and fruits pubescent = Lepidium appelianum Fruits broadest near the base = Lepidium draba Fruits broadest near the middle or tip = Lepidium chalepense

Characteristics

Flower Color
  • White
Inflorescence Type (How the flowers are arranged on the plant)
  • Axillary racemes
  • Corymb
  • Panicle
  • Terminal raceme
Number of Petals
  • 4 petals
Petal Separation
  • Completely free to base
Petal Tip
  • Rounded
Flower Symmetry
  • Flowers regular
Flower Length (Head length in the Asteraceae)
  • 2 mm (.08 inch)
  • 3 mm (.12 inch)
  • 4 mm (.16 inch)
  • 5 mm (.20 inch)
Flower Width (Head width in the Asteraceae)
  • 2 mm (.08 inch)
  • 3 mm (.12 inch)
  • 4 mm (.16 inch)
Number of Sepals
  • 4 sepals
Sepal Separation
  • Completely free to base
Sepal Tip
  • Pointed
  • Rounded
Flower Sex
  • Bisexual (perfect)
Number of Styles
  • 1 style
Number of Stamens
  • 6 stamens
Stamens Attached to the Petals
  • Stamens NOT attached to the petals
Stamens Connate (united)
  • Filaments or anthers NOT united

Carpel Separation
  • Carpels united (or one)
Number of Carpels
  • 2 carpels
Ovary Position
  • Superior (hypogynous)
Fruit Type
  • Capsule, 2-celled
Fruit Length at Maturity
  • 3 mm (.12 inch)
  • 4 mm (.16 inch)
  • 5 mm (.20 inch)
Fruit Width at Maturity
  • 2 mm (.08 inch)
  • 3 mm (.12 inch)
  • 4 mm (.16 inch)
  • 5 mm (.20 inch)
  • 6 mm (.24 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)
Leaf Width
  • 5 - 10 mm (.20 - .40 inch)
  • 1 - 2 cm (.40 - .80 inch)
  • 2 - 4 cm (.80 - 1.6 inches)
Leaf Shape (simple leaves only)
  • Lanceolate
  • Oblanceolate
  • Oblong
  • Ovate
  • Sagittate (arrowhead)
Leaf or Leaflet Margin
  • Dentate
  • Entire
  • Serrate
Leaf or Leaflet Blade Base
  • Acuminate (attenuate)
  • Auriculate
  • Clasping
  • Cordate
  • Sagittate
Leaf or Leaflet Tip
  • Acute
  • Rounded (obtuse)
Leaf or Leaflet Blade Surface
  • Puberulent
  • Pubescent
Succulence
  • Not succulent

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)
  • 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)
Wind Dissemination
  • Not wind disseminated
Moisture Regime
  • Seasonally saturated
  • Mesic
Chlorophyll
  • Present

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

Root or Vegetative Propagule
  • Rhizomatous

US State
  • Connecticut
  • Delaware
  • Illinois
  • Kansas
  • Kentucky
  • Massachusetts
  • Maine
  • Michigan
  • Missouri
  • New Jersey
  • New York
  • Ohio
  • Pennsylvania
  • Texas
  • Virginia
  • Wisconsin
  • West Virginia
  • Indiana
  • Maryland
  • Rhode Island
  • Vermont
  • 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
  • Nova Scotia
  • Ontario
  • Quebec
  • Alberta
  • Manitoba
  • Saskatchewan
Other
  • District of Columbia

  • An Illustrated Guide To Arizona Weeds, 1972 (ISBN 0-8165-0288-9) 338 pages. See page: 144
  • Aquatic and Riparian Plants of the West, 2003 (ISBN# 1-879906-59-7) See page: 175
  • The Biology of Canadian Weeds: Canadian Journal of Plant Science Vol54 PG 149
  • California Growers Weed Identification Handbook, 1968 - 1998 University of California Publication # 4030-1, See page: 61
  • Common Weeds of the Canadian Prairies, 1963 (Cat# A53-1136-1) See page: 28
  • Common Weeds of the United States, 1971 (ISBN 0-486-20504-5) See page: 200
  • Field Guide To The Common Weeds Of Kansas, 1983 (ISBN 0-7006-0233-X) See page: 45
  • Garden Weeds of Southern California, 1981, See page: 48
  • Gilkey`s Weeds of the Pacific Northwest, 1980 (ISBN 0-88246-039-0) See page: 129
  • Nebraska Weeds, 1979 Nebraska Dept. of Ag., Lincoln NE, See page: 75
  • Northwest Weeds, 1990 (ISBN 0-87842-249-8) See page: 43
  • Ontario Weeds, 1992 Agdex 640, Publication #505 See page: 105
  • Selected Weeds of Oregon, 1985 and 1989 Supplement (s) Oregon State Dept. of Agriculture, See page: 32
  • South Dakota Weeds, 1967 South Dakota State University, See page: 17
  • South Dakota Weeds 2002 South Dakota Dept. of Ag. 523 E. Capitol, Foss Bldg. Pierre, South Dakota 57501 See page: 24/25
  • S.W.S.S. Weed ID Guide, 1993 Section Number and Five letter code: 12 CADDR
  • Weed Seeds of the Great Plains, 1993 University of Kansas# 92-125-B ISBN# 0-7006-0651-3 See index #: 69
  • Weeds, 1955 (1980) Walter Conrad Muenscher, ISBN# 0-8014-1266-8 See page: 239, 240
  • Weeds, A Golden Guide, 1972 ISBN#0-307-24353-2 See page: 61
  • Weeds, 1957 Illinois State Dept. of Ag., See page: 16
  • Weeds and Poisonous Plants of Wyoming and Utah 1987 (ISBN 0-941570-06-1) See page: 50
  • Weeds of Alberta, 1983 Alberta Environmental Centre Agdex 640-4, See page: 113
  • Weeds of California, 1970, State of California Publications and Documents. See page: 220
  • Weeds of California and other Western States, 2007 (ISBN 13: 978-1-879906-69-3) See Page: 478
  • Weeds of Canada, 1970 Canada Dept. of Ag., Pub. # 948, See page: 81
  • Weeds of Colorado, 1990 Cooperative Extension, Colorado State Univ. Bulletin 521A, See page: 88
  • Weeds of Eastern Washington and Adjacent Areas, 1972 (LOC 72-83635) See page: 146
  • Weeds of Nebraska and the Great Plains, 1994 (ISBN 0939870-00-4) See page: 202
  • Weeds of the Midwestern United States & Central Canada, University of Georgia 2010, ISBN#0-8203-3506-1 See page: 151
  • Weeds of the North Central States, 1981 Univ. of Illinois, Urbana - Champaign Bulletin # 772, See page: 92
  • Weeds of the Northeast, 1956, Univ. of Delaware Field Manual #1 See species #: 148
  • Weeds of the Northern United States and Canada, 1964 Montgomery See page: 71
  • Weeds of the Northern U.S, and Canada, 1999 Royer and Dickinson, (ISBN# 1-55105-221-0) See page: 272 - 273
  • Weeds of the United States and Their Control, Lorenzi 1987, ISBN# 0-442-25884-4 See page: 156
  • Weeds of the West, 1992 (ISBN 0941570-13-4) See page: 222
  • Weeds of the West, 2000 (ISBN 0941570-13-4) See page: 220
  • Weeds of Utah, 1971 UAES Special Report 21, See page: 43
  • Listed as a `Weed` by the Biota of North America Program, 2008 X
  • Listed in the WSSA Composite List of Weeds X
Back to Plant List