30 DIFFERENT STRUCTURES OF THE PERICARP. 



The dissepiments are either parallel to the valvules, as in Luna* 

 ria and l)R.\BA;...or placed the contrary way, as in Biscutella 

 and Thlaspi. 



The most considerable differences in the Figure of the pericar- 

 pium, with the names assigned for each, have been explained in 

 Chap. VI. It varies farther in being turbinate, narrowing like a 

 child* s top, as' in Pyrus inflate, puffed, as in CardiosperMum 

 and Staphyl.ea membranaceous, composed of thin membranes, as 

 in UlMus j.. r triquetrous, tetragonous, pentagonous, of three, four, 

 or jive sides, as in Averrhoa, Zygofhyllum, &e....or articulate, 

 jointed, as in Ornithopys, Hedysarum, and Raphnus. 



The Opening of the pericarpium for discharging the seeds 

 when the fruit is ripe, is either at the apex, which may be qua- 

 dridentate, split into four segments, as in DiantHus; ...quinqueden- 

 tate, into five, as in Alsine;...oi- decemdentate'i into ten, as in 

 Cerastium ; . ..opening at the base into three parts, as in Triglochin 

 and Campanula;. ..or into five parts, as in Ledum ;...at the angles, 

 corners, longitudinally, lengthways, as in Oxalis and Orchis 

 through a pore, hole, as in Campanula or horizontally across 

 the middle, as in Anagallis, Plantago, Amaiianthus, Portulaca, 

 and Hyoscyamus. 



All fruit that is articulate, jointed, opens at every one of the 

 joints, each of which is monospermous, single seeded. 



The Confinement of the seeds is sometimes elastic, bursting 

 like a spring, as in Oxalis, Elaterium, Momordica,Tmpatiens, 

 Cardamime, Phyllanthus, Euphorbia, Justicia, Ruellia, Dic- 

 tamnus, Hura, Ricinus, Tragia, Jatropha, Croton, Clusia, 

 Acalypha. 



The Situation of the pericarpium is at the receptacle of the 

 flower, either placed under it, as in Vaccinium and Epilobium ; 

 ...over it, as in Arbutus and Tulip a ;...or both above and below 

 it, as in Saxifraga and Lobelia. 



