The development of spatial pattern in shoots of Linaria vulgaris (Scrophulariaceae) growing on fallow land or in a barley crop

Linaria vulgaris root pieces 10 cm long with 10 cm tall shoots were planted with a barley crop and on fallow land in 1988 and 1989. Positions of new shoots of L. vulgaris were recorded once a week throughout both summers. Densities of L. vulgaris stands growing on fallow land were similar in both 1988 and 1989, ranging from 167 shoots∙m −2 in August to 247 shoots∙m −2 in October. Densities of L. vulgaris stands growing with a barley crop varied between years, ranging between 1587 and 539 shoots∙m −2 from August to October in 1988 and being relatively stable at 95 shoots∙m −2 between August and October in 1989. Stand diameter was consistently greater when on fallow land than in barley, with a maximum diameter of 1 m in 1988 and 2 m in 1989 when on fallow land, and a maximum diameter of 40 cm in 1988 and 1 m in 1989 in barley. In both years, new shoots produced in a week emerged in primary clumps 5–10 cm in diameter, and these were aggregated into secondary clumps that grew larger with time. Primary clumps on fallow land were produced in rings around initial stands, whereas when growing with barley they were scattered around and within initial L. vulgaris stands.