CISTIFLORJE. 413 



Order 10. Dilleniaceae. Gynoeceum usually apocarpous, seed arillate. The 

 flower has most frequently S5, P5, and compound stamens (one or more 

 bundles) ; sometimes irregular. 200 species ; Tropical ; woody plants, many 

 lianes. Dillema, Candollea, Pleurandra, Davilla, etc. 



Order 11. Elatinaceae (Water-worts). About 25 species belong to 

 this order ; especially in temperate climates. They are small, creeping, rooted, 

 aquatic plants, with opposite or verticillate leaves and stipules. The flowers 

 are solitary or situated in small dichasia in the leaf-axils, they are small, 

 regular, $ , hypogynous, with free petals, the same number in all 5 whorls 

 (Sn, Pn, An + n, Gn), 3-merous (e.g. Elatine hexandra), 4-merous (e.g.E. hydro- 

 piper), or 5-merous (Bergia) ; the corolla-stamens are sometimes suppressed ; 

 petals imbricate without being twisted ; the ovary is 3-4-5 -locular, with 3-4-5 

 free styles the capsule dehisces septicidally. The seeds are orthotropous or 

 curved, often transversely ribbed, endosperm wanting. The order is most 

 nearly allied to Hypericaceffl, whose primitive form it appears to represent. 



FIG. 426. -Diagram of Hypericum quadran- FIG. 427. Hypericum. Flower with 



gulum: S indicates the bud of the helicoid three bundles of stamens. 



cyme in the axil of the bracteole /3. 



Order 12. Hypericacese (St. John's-worts). This order 

 is recognised by its always opposite or verticillate, simple, and 

 entire, penninerved leaves, without stipules, and usually dotted 

 with pellucid glands ; by the always J , regular, hypogynous flowers 

 in a cymose inflorescence ; the generally 5-merous calyx and 

 corolla, with sepals and petals free ; the stamens 3-5, numerously 

 branched (Figs. 426, 427) ; and the gynoeceum, 3-5-carpellate, 

 styles usually free. The ovary is 3-5-locular, or unilocular with 

 3-5 parietal placentae. Fruit a capsule (dehiscing septicidally) or 

 berry. Endosperm absent. 



The inflorescence is a dichasiurn or helicoid cyme. The structure of the 

 flowers is the same as that of the foregoing orders : S5 , P5 ; succeeding these 

 in some cases are t',vo 5-merous whorls of stamens in regular alternation, of 



