Author: C. F. Chang and B. M. Xia
J Integr Plant Biol 1964, 12 (2): -.
Gracilaria foliifera (Forssk.) Borgs. was first described from the Red Sea by Forsskal in 1775 under the name Fucus foliifer Forssk., among whose synonyms, Borgesen (1932: 7) listed G. lacinulata (Vahl) Howe and G. multipartita (Clem.) J. Ag., G. textorii (Suring.) De Toni was originally described from Japan by Suringar in 1867 under the name Sphaerococcus (Rhodymenia) textorii Suring., among whose synonyms, Dawson (1944, 1949) and Ohmi (1955) listed G. vivipara S. et G., G. sinicola S. et G., G. johnstonii S. et G. and G. vivesii Howe. In China, G. foliifera has previously been reported from Peitaiho (Collins, 1919, under G. multipartita; Howe, 1924, under G. lacinulata), Tsingtao (Howe, 1934; Tseng and Li, 1935) and Chefoo (Tseng and Li, 1935). G. textorii has already been reported from Tsingtao (Tseng and Li, 1935; Tseng and Chang, 1952, 1959, 1963). The latter is a very common species in the northern Chinese marine flora. As pointed out by De Toni (1897; 449) and May (1948: 42), G. textorii has a close resemblance to G. foliifera and it is rather difficult to distinguish the two species. Although Okamura (1900) and Ohmi (1955) each gave a detailed account of G. textorii, but no one seems to have published a critical study of G. foliifera (Forssk.) Borgs. Very fortunately, some foreign specimens including a few authentic specimens from various sources deposited in the Herbarium of the Institute of Oceanology, Academia Sinica, were available for our study, thus rendering the present study possible. The writers were at first tempted to refer G. textorii as a forma of G. foliifera, but later, after a thorough study of the specimens available, we found two differences between the two related species in the structure of cystocarp. In G. foliifera, the pericarp consists of many layers of cells, of which cells of the outermost layer are pigmented and anticlinally erect, whereas those of the inner layer are colorless, connected radially and periclinally with each other by means of distinct connecting filaments with indistinct cell walls; the gonimoblast is composed of large vacuolated cells. In G. textorii, the pericarp consists of 2–3 superficial layers of anticlinally erect pigmented cells, and 6--12 inner layers of colorless, irregularly shaped, more or less loosely arranged cells with very distinct cell walls; the gonimoblast is composed of smaller vacuolated cells. After reexamination of the Chinese specimens on the basis of the above discussed characteristics, we have come to the conclusion that all of them are referable to G. textorii. The record G. foliifera should, therefore, be removed from the algal list of China. In the present paper, a discussion has been made on the geographical distribution of G. foliifera and G. textorii, on the former being an Atlantic on the latter a Pacific species. Whether both species do occur concurently in the Indian Ocean as previously reported by various algologists must be verified by reexamination of this specimens involved.