264 SYSTEMATIC BOTANY. 



2-4-celled ovary, calyx-teeth valvatein the hud, or obsolete; the epigynous 

 petals convolute ; stamens as many, or twice as many, as the petals, and 

 inserted with them ; ovary 2-4-celled ; styles united ;" stigma capitate or 

 4-lobed ; fruit capsular or succulent, with 2-4 cells ; seeds numerous, 

 without perisperm. Illustrati ve Genera : (Enothera, L. ; Clarkitij Pursh. ; 

 JEpilobium, L. j Fuchsia, Plum, j Circaa, Tournef. ; Trapa, L. 



Affinities, &c. Onagrads are allied to Haloragese, but differ in their often 

 coloured calyx, absence of perisperm, and simple style, from Trapa in 

 their convolute imbricate corolla, from Combretaceae % their plurilocular 

 ovary. The parts of the flower in this Order are sometimes 2-merous, as 

 in Circaa, while in Lopezia only one stamen exists. Sometimes the petals 

 are absent ; and occasionally the flowers are unisexual. Trapa is a genus of 

 water-plants sometimes placed with Haloragaceae, from which, however, 

 its single style and aperispermic embryo separate it. The floating leaves 

 are flat, wedge-shaped, and entire, while the submerged ones are cut up 

 into numerous very fine segments. The germination of Trapa resembles 

 that of some endogenous plants. 



Distribution. The Order consists of a considerable number of species, 

 natives chiefly of temperate Europe, North America, and India. 



Qualities and Uses. Harmless, sometimes slightly astringent. The 

 berries of some Fuchsias are edible. They are best known by the nume- 

 rous garden plants belonging to the Order, most of which are very showy. 

 Epilobium has many native species, which are mostly weeds. E. angusti- 

 folium, however, and E. hirsutum are tall and handsome plants. Some 

 of the CEnotherce are called Evening-Primroses, from the yellow flowers 

 opening in the evening. Trapa produces a large horned fruit with amygda- 

 loid seeds with unequal cotyledons. T. natans is the Water-chestnut of 

 the French. The seeds of t. bispinosa, the SiniHiara-nut (Kashmir), and 

 T. bicomis (China) furnish important articles of food. 



HALOKAGACEyE are aquatic plants, with small axillary 2-4-merous 

 flowers, often imperfect ; calyx adherent, its teeth obsolete ; petals often 

 wanting; stamens 1-8; fruit indehiscent, 1-4-celled, with a solitary 

 suspended seed in each cell; perisperm fleshy. Illustrative Genera: Hip- 

 puris, L. ; Myriophyllum, Yaill. ; Halorauis, Forst, They are distinguished 

 from Onagraceee by the reduced calyx and the solitary pendulous and 

 perispermic seeds ; the corolla is absent from Hippuris and Proserpinaca. 

 The former genus has a very simple flower, consisting merely of an ad- 

 herent calyx with a. very short limb, an ovary of one < arpel, and a single 

 stamen. The whorled foliage of Hippuris and Myriophj/llum is curious, 

 giving the first the appearance of an Equiaetum, while the latter are like 

 some of the branched freshwater Alga3. Most of the Order are aquatic ; 

 but Haloragis and Loudonia are terrestrial and more or less shrubby. 

 They are universally diffused, but of little importance. 



LYTHBACEJ?. THE LOOSESTRIFE OEDER. 



Diagnosis. Herbs, shrubs, or trees, with mostly opposite entire leaves ; 

 no stipules ; the calyx enclosing, but free from, the 1-4-celled, many- 



