218 BIOCHEMICAL SYSTEMATICS 



Roberts et al. (1958) investigated the phenolic constituents of 

 tea varieties as well as other species of the genus Camellia, and their 

 results are of considerable interest because of the type of problem in- 

 volved. It is rather Ukely that prolonged cultivation of the tea plant 

 may have almost obliterated the recent natural species history. In 

 fact, according to Kingdon-Ward (1950) "wild tea" as such, no longer 

 occurs, and despite the fact that tea taxa are recognized, the large 

 number of cultivated "varieties" must be subjectively assigned to one 

 of several major cultivar types or else they are classified as putative 

 hybrids. Roberts et al. initiated their study on the premise that, "If 

 the chemical compound could be shown to be a feature of one or the 

 other of the taxa conceived by botanists, then the chemical definition 

 could be accepted as relevant to a natural system of classification and 

 need not be regarded as a special or artificial classification restricted 

 to the circumstances of cultivation." 



Tea plants are usually considered derived from Camellia 

 sinensis (China tea) or C. sinensis var. assamica (Assam tea). A 

 rather extensive phenolic complex is typical of the vegetative shoots 

 of the species, including several catechins, depsides such as galloyl- 

 quinic and chlorogenic acids, flavonols, anthocyanins, and leucoantho- 

 cyanins. Trihydroxy derivatives (for example, galhc acid, gallocate- 

 chin, myricetin, and leucodelphinidin) of these classes are prominent 

 in the species. Anthocyanin is more characteristic of shoots of the 

 China variety. In general, Assam tea lacks anthocyanin. The so- 

 called "southern" form of Assam, in the opinion of Roberts et al., has 

 been crossed with the China variety, and this accounts for the appear- 

 ance of anthocyanin in the form. It is interesting that these authors 

 reported that leucoanthocyanins were of sporadic occurrence, some- 

 times absent, sometimes abundant, and it was not possible to 

 associate them with a particular kind of tea. 



These investigators further found that triglycosidic flavonols 

 were common in the China variety but not in the Assam tea variety 

 (except in trace amounts in some instances). An independently iso- 

 lated southern form contained a substance known as IC, which gave 

 an orange color with aluminum chloride, but which unfortunately was 

 not further characterized. The substance was absent from all other 

 tea varieties tested but was present in two other species of the section 

 Thea, namely Camellia taliensis and C. irrawadiensis. The authors 

 considered that this evidence opened the possibility that some popu- 

 lations of cultivated tea were derived as species hybrids. While such 

 statements are conjectural at present, the work illustrates another 

 possible apphcation of biochemical data to systematics. It is noted 

 that otherwise the three species which comprise the section Thea are 



