Plant Assessment Form

Lepidium draba

Synonyms: Cardaria draba

Common Names: heart-podded hoary cress, whitetop

Evaluated on: 4/15/04

List committee review date: 14/05/2004

Re-evaluation date:


Milad Sarkis
Saint Mary's College of California
P.O. Box 4093, MOraga, CA 94575
(925) 631-5384

List committee members

Carla Bossard
Cynthia Roye
Alison Stanton
Peter Warner
Joe DiTomaso

General Comments

Removed second scientific name, Cardaria draba, and added it to the synonym line 3/28/17. Ramona Robison

Table 2. Criteria, Section, and Overall Scores

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

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? B Reviewed Scientific Publication
Identify ecosystem processes impacted:

Possibly disrupts nitrogen cycle in soil Possibly disrupts Nitrogen cycle, thus weekeing out other native species

Sources of information:

Corliss, Julie. Tall Whitetop's Crowding Out the Natives. Agricultural Research, May 16 1993.

Question 1.2 Impact on plant community composition,
structure, and interactions?
B Other Published Material
Identify type of impact or alteration:

Decreases survivorship of native species large dispersal rate of seeds

Sources of information:

Miller, Timothey W. Hoary Cress and Related Whitetops, Nov. 1991. 50/0/50

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

No alteration of higher trophic levels

Sources of information:

none noted

Question 1.4 Impact on genetic integrity? D Reviewed Scientific Publication

Slight chance of hybridiization with other Cardaria sp.

Sources of information:

Mulligan, The biology of Canadian Weeds, 1974. Canadian Journal of Plant Science. 54:149-160

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

Can occasionally establish in undisterved areas, but easily established in disturbed areas Can easily spread through human disturbances

Sources of information:

Stougaard, Robert et al. Weed Technology. 199 Volume 13:581-585

Question 2.2 Local rate of spread with no management? B Anecdotal
Describe rate of spread:

Increasing rate of spread, but less rapidly without control 1,400-4,800 seeds per plant, which can allow for a decent increase. Described as a "prolific seed producer"

Sources of information:

Stougaard, Robert et al. Weed Technology. 199 Volume 13:581-585

Question 2.3 Recent trend in total area infested within state? B Other Published Material
Describe trend:

increasingly slowly due to efforts to stop control. over half of the state (CA) seems to be infested large infestation, but with slow growth effort by seeds

Sources of information:

Question 2.4 Innate reproductive potential? A Reviewed Scientific Publication
Describe key reproductive characteristics:

High reproductive potentional High seed producer, but greatest development from roots

Sources of information:

Stougaard, Robert et al. Weed Technology. 199 Volume 13:581-585

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

Hay, Soil, and cut alfalfa human caused disperal is the most common means of dispersal

Sources of information:

Question 2.6 Potential for natural long-distance dispersal? C Anecdotal
Identify dispersal mechanisms:

no lond distance dispersal noted,unless by humans seed dispersal not important, but people are no abiotic dispersal

Sources of information:

no source noted

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

unshaded, disturbed, grasslands, scrubs, generally alkali soil Grows esily in many dry soils

Sources of information:

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

Unkown when it entered California, but entered US via New York in 1898 Introduced by ballust water, but spread easily

Sources of information:

Question 3.2 Distribution/Peak frequency? C Reviewed Scientific Publication
Describe distribution:

Sources of information:

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter Yes
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 Unknown
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: 6
Total unknowns: 2
Total score: A?

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 prairieD, < 5%
valley and foothill grasslandC, 5% - 20%
Great Basin grassland
vernal poolC, 5% - 20%
meadow and seepD, < 5%
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forestD, < 5%
riparian woodlandD, < 5%
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): B
Distribution (highest score): C

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