Laserfiche WebLink
254 Appendix 4: Profiles of Colorado State-Lis[ed Noxious Weeds <br />Yellow toadflax (Linaria vulgaris) <br />=List B <br />Yellow toadflax <br />Linaria vulgaris P. Miller <br />Family: Scropliulariaceae (Figwort) <br />Other Names: butter and eggs, wild snapdragon, common toadflax <br />USDA Code: LIW2 <br />Legal Status: Colorado Noxious List B (top ten worst) <br />Identification <br />Growth form: Perennial forb <br />Flower: Flowers are bright yellow and resemble snapdragons. <br />Flowers are arranged in a raceme at the ends of the branches. <br />Seeds/Fruit: Seed capsules are round-ovate, 0.3-0.5 inches long, and <br />two-celled. Seeds are brown or black, circular, and surrounded by a <br />notched wing. <br />Leaves: Leaves aze sofr, lance-shaped, and pale green. Leaves are <br />mainly alternate but lower leaves appear to be opposite due to <br />crowding. <br />Stems: Mature yellow toadflax plants are 1-3 feet tall with 1-25 smooth <br />erect floral stems. <br />Roots: Taproots maybe up to a meter in length. Horizontal roots may <br />grow to be several meters long, and can develop adventitious buds that <br />may form independent plants. <br />Seedling: No information available. <br />Other: Closely related to Dalmatian toadflax (Linaria dalmatica). <br />Similar Species <br />Exotics: Leaves of Dalmatian toadflax (Linaria dalmatica) aze shorter, <br />wider, and broadbased, clasping the stem. <br />Natives: None known. <br />Im acts <br />Agricultural: Yellow toadflax contains a poisonous glucoside that is <br />reported to be mildly poisonous to cattle (Morishita 1991). However, <br />the plant is considered unpalatable and reports of livestock poisonings <br />are rare. <br />Ecological: Yellow toadflax is quick to establish in open sites and is <br />capable of adapting growth to a wide range of environmental conditions. <br />Yellow toadflax aggressively forms colonies through adventitious buds <br />from creeping root systems. These colonies can push out native grasses <br />and other perennials, thereby altering and simplifying the species <br />composition of natural communities and reducing forage production for <br />livestock and wildlife. <br />Human: No information available. <br />Habitat and Distribution <br />General requirements: Yellow toadflax has a highly variable habitat <br />that depends on environmental factors such as shading, grazing, and soil Type (Saner et al. 1995), <br />