142 BIOCHEMICAL SYSTEMATICS 



Quercus, but not as a family character. In contrast, pinitol is signif- 

 icant at the family level. While pinitol is common in the Pinaceae, it 

 is not the pines that provide the example to be cited, for pinitol occurs 

 in other families of conifers. Even in the Leguminosae, where pinitol 

 apparently occurs throughout most of the tribes, it is not widespread 

 among the tribes Vicieae and Phaseoleae (Dangschat, 1958). However, 

 in the Caryophyllaceae pinitol approaches a family diagnostic charac- 

 ter. Plouvier (1954) examined forty-five species of this family rep- 

 resenting all sub-families (Paronychioideae: four genera, five species; 

 Alsinoideae: six genera, thirteen species; and Silenoideae: six genera, 

 twenty-seven species) and found pinitol to be present in forty-three of 

 the forty-five species. Repeated attemps to detect pinitol in Stellaria 

 media and Silene schafta were negative, so one could not consider 

 pinitol to be infallibly diagnostic. Yet, Plouvier states: 



It appears as a constant chemical character of the Caryophyllaceae 

 providing biochemical homogeneity in this morphologically hetero- 

 geneous family; it establishes a connection between the three sub- 

 families particularly between the Apetaly and Dialypetaly which many 

 authors consider to be separate families. 



Plouvier then extended his investigation to include twenty- 

 seven species belonging to related families, including Chenopodiaceae, 

 six genera; Amaranthaceae, four genera; Nyctaginaceae, two genera; 

 Aizoaceae, three genera; Phytolaccaceae, one genus; and Portulacaceae, 

 one genus. All of the above-mentioned families were included in the 

 Centrospermae of Engler and Diels (1936). In addition selected 

 famihes of the order Geraniales, which, according to some workers, are 

 phylogenetically close to the Caryophyllaceae were examined. These 

 included Oxalidaceae, one genus; Geraniaceae, three genera; Tropaeo- 

 laceae, one genus; Linaceae, one genus; and Zygophyllaceae, two 

 genera. Although the sample in each family was small, it is note- 

 worthy that only six of the twenty-seven species contained pinitol, 

 and it was absent from the families Amaranthaceae and Chenopodi- 

 aceae. The six positive species were: Nyctaginaceae, Mirabilis jalapa, 

 M. longiflora, and Bougainvillea glabra; Phytolaccaceae, Phytolacca 

 americana; Aizoaceae, Tetragonia expansa; and Zygophyllaceae, 

 Zygophyllum fabago (in low yield). Only the last-named famiily is 

 placed in the order Geraniales. Evidence with respect to the presumed 

 affinity between the two orders concerned is too limited to be 

 significant. 



Since pinitol is shown to be present in several families of the 

 Centrospermae however, it appears that the utilization of pinitol as a 



