Appendix 1.

Voucher and location information for the Salix humboldtiana populations used in this study. The vouchers are deposited in Herbarium Marburgense, University of Marburg, Marburg, Germany.

Population	Locality	Geographic coordinates	N	Voucher no.	Herbarium ID	Collector
RNo03	Allen, Río Negro, Argentina	39°2′43.50″S, 67°47′44.34″W	29	RNo03-26	MB-001506	Bozzi, J.
RNo13	Beltrán, Río Negro, Argentina	39°16′13.96″S, 65°49′26.86″W	31	RNo13-06	MB-001538	Bozzi, J.

Note: N = number of individuals sampled.