Plant Assessment Form

Lepidium appelianum

Synonyms: Cardaria pubescens

Common Names: hairy whitetop

Evaluated on: 12/28/04

List committee review date: 08/07/2005

Re-evaluation date:


Elizabeth Brusati, project manager
California Invasive Plant Council
1442A Walnut St. #462, Berkeley, CA 94709
Joseph DiTomaso
University of California-Davis
Dept. Plant Sci., Mail Stop 4, Davis, CA 95616

List committee members

Joe DiTomaso
Joanna Clines
Cynthia Roye
Doug Johnson

General Comments

Least common of Cardarias, and least amount of information available.
Removed second scientific name, Cardaria pubescens, and added it to the synonym line 3/28/17. Ramona Robison

Table 2. Criteria, Section, and Overall Scores

Overall Score? Limited
Alert Status? No Alert
Documentation? 3 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes U. Unknown Reviewed Scientific Publication
Four-part score UCUD Total Score
1.2 ?Impact on plant community C. Minor Reviewed Scientific Publication
1.3 ?Impact on higher trophic levels U. Unknown
1.4 ?Impact on genetic integrity D. None Other Published Material
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Other Published Material
Total Points
11 Total Score B
2.2 ?Local rate of spread with no management B. Increases less rapidly Other Published Material
2.3 ?Recent trend in total area infested within state C. Stable Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
B. Moderate Other Published Material
2.5 ?Potential for human-caused dispersal C. Low Other Published Material
2.6 ? Potential for natural long-distance dispersal B. Occasional Other Published Material
2.7 ?Other regions invaded C. Already invaded Other Published Material
3.1 ?Ecological amplitude/Range
(see Worksheet C)
C. Limited Other Published Material
Total Score C
3.2 ?Distribution/Peak frequency
(see Worksheet C)
D. Very low Observational

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".

Section 1: Impact
Question 1.1 Impact on abiotic ecosystem processes? U Reviewed Scientific Publication
Identify ecosystem processes impacted:

Not as common as Cardaria draba. Cardaria draba disrupts the nitrogen cycle or reduce soil moisture availability but there was no information on this for C. pubescens in any of our literature.

Sources of information:

Question 1.2 Impact on plant community composition,
structure, and interactions?
C Reviewed Scientific Publication
Identify type of impact or alteration:

Sources of information:

Question 1.3 Impact on higher trophic levels? U
Identify type of impact or alteration:

May reduces biodiversity and wildlife habitat, but this is unknown. Bees use nectar (1). Very little information available on this species.

Sources of information:

Sheley and Stivers 1999

Question 1.4 Impact on genetic integrity? D Other Published Material

none No native Cardaria species

Sources of information:

Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA

Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
B Other Published Material
Describe role of disturbance:

Primarily inhabits disturbed areas, such as irrigated pastures, rangelands, roadsides, and ditch banks, but can move into meadows and along streams. Needs open areas. Scored as B because establishment seems to depend upon, or at least be greatly facilitated by, disturbance.

Sources of information:

Sheley and Stivers 1999

Question 2.2 Local rate of spread with no management? B Other Published Material
Describe rate of spread:

No specific information on infestations within California but probably does not spread as rapidly as C. draba. Can spread by 0.6 to 1.5 m radius each year.

Sources of information:

DiTomaso J.M. and E. A. Healy. in prep Weeds of California and Other Western States.
Sheley and Stivers 1999

Question 2.3 Recent trend in total area infested within state? C Observational
Describe trend:

Sources of information:

DiTomaso, observational

Question 2.4 Innate reproductive potential? B Other Published Material
Describe key reproductive characteristics:

Perennial, with spreading root system that produces aerial shoots. Spread is primarily by persistent roots (1, 2). Plants are reported to produce about 30-560 (average 300) pods per plant. Self-incompatible. Root fragments can generate new plants (3).

Sources of information:

1. Mulligan and Findley 1974
2. Sheley and Stivers 1999
3. DiTomaso J.M., and E. A. Healy. In prep. Weeds of California and Other Western States.

Question 2.5 Potential for human-caused dispersal? C Other Published Material
Identify dispersal mechanisms:

Not much opportunity to spread my human means. Found along roadsides and in pastures

Sources of information:

Sheley and Stivers 1999

Question 2.6 Potential for natural long-distance dispersal? B Other Published Material
Identify dispersal mechanisms:

Seeds spread by wind and in waterways. Most spread is vegetative, but some seed is produced.

Sources of information:

Sheley and Stivers 1999

Question 2.7 Other regions invaded? C Other Published Material
Identify other regions:

Argentina, central and western Canada and United States (1). Listed as noxious weed in Arizona, Oregon, Utah, Washington, and Wyoming (2).

Sources of information:

1. Mulligan and Findley 1974
2. DiTomaso and Healy in prep

Section 3: Distribution
Question 3.1 Ecological amplitude/Range? C Other Published Material

Introduced sometime in 1800's or early 1900's, possibly in contaminated seeds. Inhabits disturbed open sites, fields, pastures, grain and vegetable crops, especially irrigated crops such as alfalfa and sugar beets, orchards, vineyards, roadsides, ditches. Often grows on moderately moist, alkaline to saline soils, but tolerates a wide range of soil types and moisture conditions. Scattered throughout California but uncommon in desert regions. More frequent in the Sacramento Valley, southwestern region, and Great Basin to 2000m (1). Grows in open, unshaded, usually disturbed areas (2). Scored as A because so widespread, but I'm not sure how to fill out worksheet C

Sources of information:

1. DiTomaso and Healy in prep
2. Sheley and Stivers 1999

Question 3.2 Distribution/Peak frequency? D Observational
Describe distribution:

Typically only found in the northeastern part of the state near streams.

Sources of information:

DiTomaso, observational.

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter No
Populations of this species produce seeds every year. Yes
Seed production sustained over 3 or more months within a population annually No
Seeds remain viable in soil for three or more years Unknown
Viable seed produced with both self-pollination and cross-pollination No
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes Yes
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned Yes
Total points: 4
Total unknowns: 1
Total score: B?

Related traits:

Worksheet B - Arizona Ecological Types is not included here

Worksheet C - California Ecological Types

(sensu Holland 1986)
Major Ecological Types Minor Ecological Types Code?
Marine Systemsmarine systems
Freshwater and Estuarine lakes, ponds, reservoirs
Aquatic Systemsrivers, streams, canals
Scrub and Chaparralcoastal bluff scrub
coastal scrub
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrub
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairie
valley and foothill grasslandD, < 5%
Great Basin grasslandD, < 5%
vernal pool
meadow and seepD, < 5%
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forest
riparian woodland
riparian scrub (incl.desert washes)
Woodlandcismontane woodland
piñon and juniper woodland
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forest
closed cone coniferous forest
lower montane coniferous forest
upper montane coniferous forest
subalpine coniferous forest
Alpine Habitatsalpine boulder and rock field
alpine dwarf scrub
Amplitude (breadth): C
Distribution (highest score): D

Infested Jepson Regions

Click here for a map of Jepson regions

  • CA Floristic Province
  • Cascade Range
  • Central West
  • Great Valley
  • Northwest
  • Sierra Nevada
  • Southwest
  • Great Basin Province
  • Modoc Plateau
  • Sierra Nevada East
  • Desert Province
  • Mojave Desert
  • Sonoran Desert