This species is rather variable Figure 2. All drawn from R.-L. Zhu 497. Botanical Bulletin of Academia Sinica, Vol. However, C. ryukyuensis is characterized by the absence of basal ocelli, the presence of subfloral innovations, and the distal hyaline papilla. But, from our study on the type specimen and Hong Kong material, the trigones are quite variable.
Most material has small, rather indistinct trigones.
But the former is autoicous while the latter is dioicous. Representative specimen examined. Tai Po Kau. It is also found in Guangdong and Hainan as a new record. In all Chinese material examined, the innovation leaf sequence is often lejeuneoid.