TETRANDRIA MONOGYNIA. 315 



HAB. Sandy sea-coast. Aug. ^ ; stem, a foot high, erect, Jirm, much 

 branched ; leaves vlllose at base. 



71. PROSERPINACA. 



P. palustris: leaves linear-lanceolate, serrate; the lower ones pin- 



natifid. 

 HAB. In water. July Aug. *2J.; root creeping ; stem partly stib- 



merg., red; Jl. small, axillary. 



TETRANDRIA. 

 MONOGYNIA. 



A. Flowers superior. 

 Genera. t Monopetalous. 



72. CEPHALANTHUS. Common calyx ; proper minute, angular, 

 4-cleft ; corolla tubular, slender, 4-cleft ; style much exserted ; stig- 

 ma globose ; capsule 2-celled, 2-seeded, (mostly 2-partiIe ;) recepta- 

 cle globose, hairy. 



73. DIPSACUS. Flowers in an ovate or roundish capitulum; com- 

 mon calyx (involucrum) many-leaved, foliaceous; proper superior, 

 of one leaf; corolla tubular, 4-cleft ; seed solitary ; receptacle conic, 

 paleaceous ; pappus cyathiform. 



74. GALIUM. Calyx 4-toothed; corolla monopetalous, rotate, 4-cleft; 

 seeds 2, globose. 



75. HOUSTONIA. Calyx 4-toothed; corolla infundibuliform, 4-cleft; 

 capsule half-superior, 2-celled, 2-valved, many-seeded, opening trans- 

 versely. 



76. MITCHELLA. Flowers by pairs upon the same germen; calyx 

 4-toothed; corolla infundibuliform; tube cylindric; limb 4-parted, 

 spreading, villous on the inner side; stamens scarcely exserted; 

 stigma 4-cleft ; berry, by the union of 2 germens, didymous, 4- 

 seeded. 



77. LINN^EA. Calyx double; that of the fruit 2-leaved, inferior; oi 

 the flower 5-parted, superior ; cor. turbinate, subcampanulate, 5- 

 lobed, equal; stamens somewhat didynamous; stigma globose; 

 berry dry, 3-celled, (only one of the cells bearing a perfect seed.) 



t t Polypetatous. 



78. SANGUISORBA. Calyx 2-leaved; cor. 4-cleft, rotate; cap* 

 quadrangular, between the calyx and corolla, 1 2-celled. 



79. CORNUS. Flowers sometimes aggregated in a 4-leaved involu- 

 crum ; calyx 4-toothed ; pet. 4 ; drupe with a 2-celled nut. 



80. LUDWIGIA. Calyx 4-parted, persistent; cor. 4-petaled or 0; cop*, 

 quadrangular, 4-celled, inferior, many-seeded. 



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