D.D.Palmer No year - Palmer DD (1998) Cibotium Xheleniae Hyb. Nov. (C. chamissoi X C. menziesii; Cyatheaceae): A Naturally Occurring Hybrid from Oahu, Hawaii. American Fern Journal 88: 150-154. doi: 10.2307/1547766.
There is no corrections for Cibotium helenae yet.