The Californian Silene multinervia (Caryophyllaceae) and Eurasian members of section Conoimorpha in subgenus Behenantha are the only Silene species that have calyces with 15 or more prominent parallel, unbranched veins. We show that S. multinervia, which has been considered a recent introduction of the Asian S. coniflora (section Conoimorpha) to North America, is clearly not synonymous with the latter species based on morphological or molecular data. We present a chromosome count of S. multinervia (2n = 24), which is different from the base number x = 10, a putative synapomorphy for section Conoimorpha. Gene trees based on sequences from three different genomes fail to group S. multinervia with the European section Conoimorpha species. The S. multinervia sequences form a monophyletic group placed in an unresolved position within subgenus Behenantha.