a multivariate statistical analysis was performed on morphological characters of sixty-one populations of avena eriantha dur. a. clauda dur., a. barbata pott ex link., a. wiestii steud., a. fatua l., a. sterilis ssp. ludoviciana l. and a. sativa l. factor analysis revealed that intraspecific morphological variations are due to quantitative characters. interspecific as well as intersectional rel...

This work is inspired by a paper of Hertel and Pott on maximum non-linear functions [8]. Geometrically, these functions correspond with quasi-quadrics; objects introduced in [5]. Hertel and Pott obtain a characterization of some binary quasi-quadrics in a ne spaces by their intersection numbers with hyperplanes and spaces of codimension 2. We obtain a similar characterization for quadrics in pr...