Invasiveness Ranking System for Non-Native Plants of Alaska

Plantago major L.Ranking SummaryEcoregion known or expected to occur inSouth CoastalInterior BorealArctic AlpineYesYesYesPotential Max. ScoreEcological Impact 40 8Biological Characteristics and Dispersal 25 13Amplitude and Distribution 25 16Feasibility of Control 10 7Relative Maximum 44Climatic ComparisonCollected inAlaska regions?common names: common plantain, broadleaf plantainCLIMEXsimilarity?South Coastal Yes –Interior Boreal Yes –Arctic Alpine Yes –Special Note–Nativity: Many experts believe this taxonoriginated in Europe (Dempster 1993, Whitson et al. 2000) andit is now cosmopolitan in distribution. However, according toUSDA Plants Database and ITIS (2003) this taxon is considerednative to Alaska, Hawaii, and the continental U.S. Hultén (1968)reported a variety with upright leaves (var. pilgeri) as possiblynative to Alaska. Hitchcock and Cronquist (1973) recognizeda native variety (var. pachyphylla Piper) of saline habitats andintroduced variety (var. major L.). Therefore, we treat this asa polymorphic taxon of primarily or exclusively non-nativegenotypes. Greater study, using molecular and morphologicalmarkers and paleoecological methods is necessary to tease apartthe patterns of nativity of this species in Alaska.Plantago major has been collected in all ecogeographic regions ofAlaska (Hultén 1968, UAM 2004).Ecological ImpactScoreImpact on Ecosystem Processes (0–10) 1Common plantain has no perceivable effect on ecosystem process(Densmore et al. 2001). Though this plant is only found in highlydisturbed environments it has potential for retarding successionafter sites have been invaded.Impact on Natural Community Structure (0–10) 3Common plantain establishes in a sparsely vegetated herbaceouslayer, increasing the density of the layer in south-central Alaska (I.Lapina pers obs.).Impact on Natural Community Composition (0–10) 1Common plantain has not been observed in undisturbed areasin Alaska, little or no impact on native populations has beenobserved (Densmore et al. 2001).Impact on Higher Trophic Levels (0–10) 3Common plantain is an alternate host for number of viruses andfungi (MAFRI 2004, Royer and Dickinson 1999). Many insectspecies feed on this plant (Sagar and Harper 1964). The seedscontain a high percentage of oil and are desirable to birds (Ohioperennial and biennial weed guide 2004). It may hybridize withnative species of Plantago.Total for Ecological Impact 8/40Biological Characteristics and Dispersal ScoreMode of Reproduction (0–3) 3Common plantain reproduces by seeds and can resprout fromroot and root fragments. Each plant is capable of producingup to 14,000 seeds (Royer and Dickinson 1999, Rutledge andMcLendon 1996, Sagar and Harper 1964).Long-distance dispersal (0–3) 3The seeds are sticky when wet, causing them to adhere to soilparticles, feathers, fur, skin, or vehicles (Ohio perennial andbiennial weed guide 2004, Royer and Dickinson 1999, Rutledgeand McLendon 1996).Spread by humans (0–3) 3The plant travels widely with humans. Seeds can be spreadby vehicles, contaminated topsoil, and commercial seeds(Hodkinson and Thompson 1997).Allelopathic (0–2) 0Common plantain has no allelopathic effects (USDA 2002).Competitive Ability (0–3) 1Common plantain is a moderate competitor if not overgrownby other vegetation (Densmore et al. 2001, Miao et al. 1991).It is known to suppress the growth of corn and oat seedlings(Manitoba Agriculture and Food 2002).Thicket-forming/Smothering growth form (0–2) 0Common plantain does not form thickets. The stem is very short,leafless flowering stalks grow to 2 feet tall (Royer and Dickinson1999). At high densities, common plantain responds by highmortality (Palmblad 1968).Germination requirements (0–3) 0Common plantain is a colonizer of disturbed soil, requiring opensoil for germination and establishment (Densmore et al. 2001).In experiments in Massachusetts (Miao et al. 1991) germinationwas significantly higher in open soil and seed germination wasgreatly reduced in established grass stands. Sagar and Harper(1964) report germination and establishment only on bare soiland sparse plant communities. No establishment was observed inany vegetated or sites with leaf litter.Other invasive species in the genus (0–3) 3Plantago media L., P. lanceolata L., and P. patagonica Jacq. (Royerand Dickinson 1999, Whitson et al. 2000).Aquatic, wetland or riparian species (0–3) 0Common plantain is common on cultivated fields, lawns,pastures, gardens, roadsides, and waste areas (Parker 1990, Royerand Dickinson 1999, Rutledge and McLendon 1996, Whitson etal. 2000).Total for Biological Characteristics and Dispersal 13/25Ecological Amplitude and Distribution ScoreHighly domesticated or a weed of agriculture (0–4) 4Common plantain is one of the most common weeds in gardens,pastures, lawns, and crop fields (MAFRI 2004, Ohio perennialand biennial weed guide 2004, Parker 1990, Royer and Dickinson1999). A red-leaved form is occasionally grown as a cultivar(J. Riley pers. com.).Known level of impact in natural areas (0–6) 1This plant appears to be having little effect on native plantcommunities or successional processes in Rocky MountainNational Park in Colorado (Rutledge and McLendon 1996).B-94