1. Department of Organismic and Evolutionary Biology Harvard University Cambridge MA 02138 USA
2. The Arnold Arboretum of Harvard University Boston MA 02131 USA
3. Jornada Experimental Range Agricultural Research Service United States Department of Agriculture Las Cruces NM 88003 USA
4. Shrub Sciences Laboratory Rocky Mountain Research Station Forest Service United States Department of Agriculture Provo UT 84606 USA
5. Harvard University Herbaria 22 Divinity Avenue Cambridge MA 02138 USA
6. University and Jepson Herbaria University of California Berkeley 1001 Valley Life Sciences Building #2465 Berkeley CA 94720 USA