Host plants of Oreina speciosissima and their altitudual zonation and habitat. According to literature  and personal observations of the authors, 13 plant species were referred to as putative host plants for Oreina speciosissima. These species belong to four plant associations, i.e. Petasition officinalis, Adenostylion, Petasition paradoxi and Androsacion alpinae , which segregate along altitudinal zonation and bedrock type gradients. Whereas Petasition officinalis and Adenostyles correspond to high forbs habitat, Petasition paradoxi and Androsacion alpinae represent stone run habitats. In particular conditions, the Petasition paradoxi can merge with high forbs (see text). Each association includes bold written codes (see Table 1 for details) of sampled populations. Plant associations are written from left to right as a function of their mean elevation, and also according to a putative scenario of colonization of central Alpine silicious stone run vegetation by specific Oreina speciosissima lineages (high forbs representing the original habitat for most Oreina species). Main host plant species of Oreina speciosissima in each of the four associations are as follows: Petasites albus in Petasition officinalis, Adenostyles alliariae in Adenostylion, Doronicum grandiflorum in Petasition paradoxi, and Doronicum clusii in Androsacion alpinae.