USDA record of procurement for cancer research (3 pages).  Includes two independent investigations, one from California and one from Arizona

Sambucus caerulea

Treated in Jepson Manual as synonym of S. mexicana, but recognized in the Intermountain Flora by the flat-topped inflorescence.

Sambucus mexicana
Kern River Canyon, Kern Co.,
CA, Apr 2005

Sambucus racemosa
Subalpine meadow, 9600 ft.,
Manti-La Sal National Forest, UT
September 2005

Sambucus racemosa
Kenai Peninsula, AK
July 2003