Changes

*''Fucus gelatinus'' Esper (1797), *''Eucheuma gelatinum'' ("''gelatinae''") (Esper) J. Agardh (1847), *''Sphaerococcus gelatinus'' (Esper) C. Agardh (1922).

*Philippines: tamso. *China: qing-zhi, shihua, shihuacai. *Japan: katamen, kirinsai.

''B. gelatinus'' has long been collected in Hainan (China) and used as a gelatinous substance in food and for wall sizing. Around 1930 the agar factory in Ningbo (Zhejiang, China) was already using this seaweed as a raw material in the manufacture of shred agar. At that time 40% of the ''Betaphycus'' (then as ''Eucheuma'' ) was mixed with 60% of the agarophyte ''Gelidium amansii'' (J.V. Lamour.) J.V. Lamour. In recent years in China, ''B. gelatinus'' has also been used in salted salad, replacing ''Eucheuma denticulatum'' (Burm.f.) Collins & Herv. Now it is especially used to produce beta carrageenan, which is mainly applied in food. In Vietnam this alga is used for making jellies, cakes, and sweet soup. In Indonesia (Lesser Sunda Islands) it is used to prepare vegetable soup (with coconut milk), and it is also applied as a vermifuge. In Chinese herbal medicine, however, ''B. gelatinus'' is not used as a vermifuge but for the treatment of goitre, scrofula, cough, tonsillitis, asthma, stomach ailments, haemorrhoids and anal fistulas.

The thick cell walls of ''B. gelatinus'' are composed of D-galatan carrageenans, which are, according to some reports, principally of the beta type mixed with small quantities of the gamma and kappa types. Beta carrageenan, which lacks sulphate groups, is relatively non-ionic and quite stiff. It is used mainly in the food industry, in the making of soft sweets with a jam centre, and canned food. Other reports, however, suggest that only low percentages (6-7%) of beta carrageenan occur in ''B. gelatinus'' , and much higher percentages of kappa carrageenan. It is probable, however, that in these cases the studied material did not belong to ''B. gelatinus'' , but in fact to ''B. philippinensis'' Doty. This is a recently described species, and is the type species of the genus ''Betaphycus'' Doty ex P.C. Silva. Gel produced by (Philippine) " ''B. gelatinus'' " has characteristics which are similar to furcellaran, the carrageenan found in the European red algal genus ''Furcellaria'' Grev. In the trade ''B. gelatinus'' is often confused with and called " ''serra'' ". This results in further considerable confusion, because genuine ''Eucheuma serra'' (J. Agardh) J. Agardh produces iota carrageenan and certainly not beta and/or kappa carrageenan.

*Thalli prostrate, entangled, attached to rocky substrate by well-developed haptera arising from crustose base and ventral side of branches, purplish-red or yellowish-green when living, leathery, pliable, irregularly branched, 10-20 cm in diameter. *Branches, arising from simple, marginal proliferations, compressed, ventral surface and margins densely covered with rows of spinose branchlets, upper surface smooth, 3-5 mm broad and 1-2 mm thick. *Rhizoidal filaments compacted, thick-walled, tortuose, central in medulla, often in a flattened core. *Life cycle triphasic, diplo-haplontic and isomorphic. *Tetrasporangia zonately divided, embedded in cortex region of main axes, clustered near and on determinate laterals. *Cystocarps borne towards the ends of proliferations from ventral or dorsal surfaces. *Spermatangia in superficial sori.

''B. gelatinus'' was originally included in ''Eucheuma'' J. Agardh section ''Gelatiforma'' Doty & J.N. Norris. The description of the type species of the genus ''Betaphycus'' ( ''B. philippinensis'' ) includes some suggestions that it contains material originally described as " ''Eucheuma gelatinus'' " from the Philippines, although its synonymy is not officially indicated. ''B. philippinensis'' has only been recorded so far from a 60 km stretch of coast near Bulusan, eastern Sorsogon Province (the Philippines) where it was collected in October and November 1987. This nomenclatural uncertainty may have resulted in different records for carrageenan types isolated from ''B. gelatinus'' . On the basis of data on carrageenan types of other taxa that were originally considered to belong to ''Eucheuma'' section ''Gelatiforma'' , it is clear that not all these species can be included in the new genus ''Betaphycus'' .

*C.K. Tseng & G.C. Trono Jr