PHANEROGAMIA 



563 



free carpels, while in the Myrtiflorae, with the exception of the 

 group Halomgidaceae, the union of the carpels is complete, extending 

 also to the stigmas. 



The vegetative organs of this order in no wise resemble those of 

 the Rosiflorae. The Myrtiflorae, on the contrary, have usually opposite, 

 entire leaves, never compound ; the leaves also are either exstipulate, 

 or the stipules are small and fugacious. In 

 this order, unlike the Rosiflorae, many of the 

 plants possess internal glands, which secrete 

 ethereal oils. 



Family Onagraceae. — Flowers epigyn- 

 ous, actinomorphic, tetramerous through- 

 out; stamens diplostemonous (Figs. 540, 

 541). 



Fig. 540. — Floral diagram of 

 Oenotlwra (Ojiat/roceae). 



The Onagraceae include only herbs and shrubs. 

 Their flowers are usually large and conspicuous, hav- 

 ing often an elongated, tubular receptacle. Their fruit is many-seeded, and may 

 be either dry or juicy. 



Representative Genera. — Epilobium (Willow-herb) has a capsular fruit with 

 hairy seeds ; Circaea (Enchanter's Nightshade), with two-ranked leaves, fruit a 

 nut ; Trapa (Horn-nut) ; Oenothera (Evening Primrose) ; Fuchsia (Fig. 541), with 

 corollaceous calyx and tubular receptacle, cultivated. These are chiefly represented 



in Northern Europe by the red- 

 flowered species of Epilobium, which 

 grow in damp places and on river- 

 banks ; and by two large yellow- 

 flowered species of Oenothera from 

 North America. 



Geographical Distribution. 

 — The Onagraceae are native chiefly 

 of the temperate zones of North 

 and South America. 



Family Haloragidaceae. — 

 Flowers very small and reduced, with 

 fp.ee stigmas ; seeds with endo- 

 sperm : e.g. Myriophyllum (Water 

 Milfoil) and Bippuris (Mare's-tail), 

 aquatic plants growing partially or 

 wholly submerged. 



Family Lythraeeae. — 



Flowers perigynous, regular 

 or zygomorphic, in perianth 



Yia.til.-FwMa.gUHma. Flowers (nat. size). ^ mdrrecium HEXAMEK0US) 



DIPLOSTEMONOUS ; gyncecium of two to six carpels. 



This family occurs for the most part in tropical America, and contains chiefly 

 herbs, rarely shrubs or trees. The flowers are usually small, either apetalous or 

 provided with a red or violet corolla ; they produce a dry indehiscent fruit. The 



