Adiantum jordanii occasionally hybridizes with A . aleuticum where their ranges overlap in northern California, yielding the sterile hybrid Adiantum × tracyi C. C. Hall ex W. H. Wagner. Adiantum × tracyi , morphologically intermediate between its parental species, can be distinguished from A . jordanii by its broadly deltate leaf blade that tapers abruptly from the 4(--5)-pinnate base to a 1-pinnate apex. It is best separated from A . aleuticum by leaf blades with a strong rachis, and by ultimate blade segments that are less than twice as long as broad. Adiantum × tracyi shows 59 univalents at metaphase; its spores are irregular and misshapen (W. H. Wagner Jr. 1962).