INTERNATIONAL CHECKLIST OF CULTIVATED ILEX 7 



or standing, and a precedent for formal validation by potential registra- 

 tion is discouraged. Group names are not to be confused with cultivar names 

 or any other ranks that have valid taxonomic or nomenclatural status. 



Status of Ilex opaca 



The taxonomic status and position of Ilex opaca as a species is clear. 

 However, there are numerous difficulties of cultivar identification between 

 interspecific hybrids, such as between /. opaca and /. X attenuata Ashe, 

 the latter reported to be a hybrid between /. opaca and /. cassine. The puta- 

 tive natural hybrid /. X attenuata and the native species /. cassine, with 

 its variations, are poorly described and inadequately understood. The 

 hybrid swarms involving /. opaca and /. cassine, thought to occur naturally 

 in the geographical zones of overlap, are problematical. A complete taxo- 

 nomic and statistical circumscription of /. cassine and its variations 

 through its entire range has never been published. After several genera- 

 tions of b acker ossing of /. X attenuata to I. cassine and /. opaca, it is 

 doubtful that any means will be developed to diagnose hybridity. 



Some cultivar names that were first published as referring to /. opaca 

 and later transferred to /. X attenuata may illustrate a possible evidence 

 of hybridity. However, some doubtful cultivar names have been retained 

 within /. opaca because of the lack of study materials, data, and any clear 

 evidence of hybridity. 



Appendix C is a separate list of doubtful cultivar names of /. opaca 

 that have never been validated by publication in any form but are known 

 to exist. Many of these names are published here for the first time. This 

 procedure prevents reuse of these obscure names as being validly applied to 

 additional and different clones. Although the plants with these invalid 

 names may be known to be in existence, the reuse of the invalid names 

 would create immense nomenclatural confusion if applied at a later time 

 to different clones. 



Some 40 or more cultivars of /. opaca with varying qualities of yellow 

 fruit are enumerated. The predominant yellow-fruited selections could be 

 referred to f. xanthocarpa Render. 3 However, for convenience, these are 

 not grouped under the botanical rank of /. opaca f. xanthocarpa, but are 

 listed in strict alphabetical order with the other cultivars cited. Many 

 variations in fruit color ranging from clear yellow through orange-yellow 

 and orange-red to red exist among selections of /. opaca. The original 

 description of f. xanthocarpa is inadequate to delimit all the known 

 parameters of fruit color. 



3 Dudley, T. R., and Eisenbeiss, G. K. handbook of hollies. Amer. Hort. Mag. 

 49(4) : 316. 1970. 



