67 



(fig. 3-4). A tubular calyx characterizes the Silene sub-family 

 of the Caryophyllaceae; an angular calyx is found in Lychnis 

 and other genera of Caryophyllaceae. A calyx very suggestive 

 of Frankenia is found in Plumbago; the possible relationship of 

 Plumbaginaceae to Caryophyllaceae has been pointed out by 

 Wettstein and others. In several Frankenia species the calyx 

 is somewhat twisted, a characteristic of Loasaceae and of 

 Mesembryanthemum. The petals with claw and ligule is another 

 character very frequent in the two families (fig. 5-6) ; the margin 

 is often fringed. The stamens, usually in two whorls, often have 

 filaments broadened below and are sometimes slightly united, 

 the anthers are extrorse in both families. 



In both families, the pistil is one-celled, frequently of three 

 carpels, developing into a capsular fruit. In numerous Frankenia 

 species there is a slight bend at the base of the style, suggestive 

 of the style of Viola. The placentation in Frankeniaceae varies 

 from parietal to basal (fig. 7-10). In Hypericopsis, and in 

 most of the Mediterranean and South American Frankenias 

 there are 20-30 ovules on parietal placentae. In F. grandifolia 

 and a number of other species only the lower parts of the 

 placentae bear ovules. In Anthobryum triandrum there are two 

 ovules just below the middle of each of the three placentae. 



In the Basigonia section of Frankenia there are usually three 

 basal ovules, in F. Jamesii and F. Fischeri three ovules basally 

 attached almost fill the ovary. In Niederleinia juniperoides three 

 ovules are attached to a single placenta. In the Silene sub- 

 family of Caryophyllaceae, the placentation is central, in the 

 Alsine sub-family there is usually one basal ovule. In another 

 family of the Centrospermae, the Aizoaceae, a parietal placenta- 

 tion occurs in species of Mesembryanthemum. In Lewisia Cotyle- 

 don in the young flower the ovules appear to be in a parietal posi- 

 tion, later with an apparently central placentation three thread-like 

 structures continue from the funiculi to the top; in dissecting, 

 three groups, each with about four ovules, readily separate. A 

 very persistent character not only in the Caryophyllaceae but 

 also in other families of the Centrospermae is the granular or 

 pearly surface of the seed, and the same character occurs gener- 

 ally in the Frankeniaceae (fig. 11). Another important char- 

 acter of the Centrospermae is the curved embryo. While this 

 character perhaps does not occur in the Frankeniaceae, it does 



