Biosystematic study of Rosa (Sect. Pimpinellifoliaeae) and described R. abrica (Rosaceae) as a new species from Iran

Fifteen populations of Pimpinellifoliaeae section from the species; Rosa pimpinellifolia، R. hemispherica، R. foetida and a new species، R. abrica، were collected from eight provinces of Iran and were studied on the basis of their morphological characters. In each population five plants were randomly selected and some branches were harvested in spring and autumn for studying their vegetative and floral characteristics. Sixty-three qualitative and quantitative characters were grouped using the most suitable method of cluster analysis (WARD) and their ordination diagram based on the most variable factors، were written for each species and the section. The results showed that the effect of ecological factors such as altitude influenced the intra-species variation. Cluster analysis illustrated high similarities between R. hemispherica and R. foetida. In the present research two unique populations of a new species (not recorded in K، W، E، G and Iranian herbaria)، named R. abrica، were also analyzed. Culster analysis separated the R. abrica as a different group compared to other species of this section. Traits such as curved prickles، high number of petals، truncate or seldom emarginated petals، indeterminate state of achenes and stigma were significant in classification of the new rose species. Although، R. abrica is very similar to R. foetida but in characters such as number of leaflets، corymbs inflorescence، entire edge of sepal or seldom with lobes، hairy style، glabrous hips and pedicels، it is significantly different from R. foetida.