Appendix Table 1. The invasive (in bold) and non-invasive confamilial study species – native to Europe and the earliest record in an online US herbarium that we found, plus the name of the herbarium.

Plant family / Species / Year of earliest record / Online herbarium in which we found this record
Asteraceae / Sonchusarvensis / 1881 / Southwest Biodiversity Consortium
Inulasalicina / NA / Present in Consortium of Pacific Northwest Herbaria
Apiaceae / Aegopodiumpodagraria / 1874 / Consortium of Northeastern Herbaria
Peucedanumostruthium / NA / Present in Consortium of Northeastern Herbaria
Poaceae / Poacompressa / 1822 / Consortium of Northeastern Herbaria
Briza media / 1887 / Southwest Biodiversity Consortium
Scrophulariaceae / Linaria vulgaris / 1873 / Consortium of Northeastern Herbaria
Veronica chamaedrys / 1903 / Consortium of Northeastern Herbaria
Lamiaceae / Glechomahederacea / 1850 / Consortium of Northeastern Herbaria
Teucriumscorodonia / 1822 / Consortium of Northeastern Herbaria
Caryophyllaceae / Saponariaofficinalis / 1822 / Consortium of Northeastern Herbaria
Silenedioica / 1885 / Wisconsin Herbaria Plant Specimens

Herbaria checked (Herbaria were assessed on October 3rd, 2012):

  • California: Consortium of California Herbaria,
  • Florida: Atlas of Florida Vascular Plants,
  • Idaho, Montana, Oregon, Washington and Wyoming: INVADERS Database System,
  • Minnesota: Herbarium of the University of Minnesota, (website temporarily unavailable)
  • New York: New York Flora Atlas, (does not list year of sample collection for our species)
  • Wisconsin: Wisconsin Herbaria Plant Specimens,
  • Oregon flora project:
  • North-East North America: Consortium of Northeastern Herbaria,
  • New Mexico: New Mexico Biodiversity collections consortium,
  • South-West USA: Southwest Biodiversity Consortium,
  • West USA: Consortium of the Intermountain Region Herbarium Network,
  • Pacific North-West North-America: Consortium of Pacific Northwest Herbaria:

Appendix Fig. 1Modeled, backtransformed means and upper and lower standard errors of a) clonal growth organ biomass b) belowground biomassc) root biomass and d) aboveground biomass of invasive (black circles) and non-invasive (white circles) clonal plant species in two pot parts:E-W (East andWest pot quarter) and N-S (North and South pot quarter). In the homogeneous treatment, all four pot quarters received an equal amount of nutrients. In the heterogeneous treatment, all nutrients were added to the North and South quarters of the pot (high), whereas the East and West quarters did not receive any extra nutrients (low). Significances of the differences are given in Table 2. For those analyses in which block significantly improved model fit, modeled means and standard errors were calculated using the general linear hypothesis function from the statistical package multcomp(Hothorn et al., 2008).

AppendixFig. 2Modeled and backtransformed means and upper and lower standard errors ofthe total biomass of invasive (black circles) and non-invasive (white diamonds) clonal plant species in homogeneous and heterogeneous nutrient environments. Significances of the differences are given in Table 2. Modeled means and standard errors were calculated using the general linear hypothesis function from the statistical package multcomp(Hothorn et al., 2008).

Hothorn, T., Bretz, F., & Westfall, P. (2008). Simultaneous inference in general parametric models. Biometrical Journal, 50(3), 346–363.