TETRANDRIi. MONOGYNIA. 103 



Species. 1. F. Walteri. From Canada to Carolina. 

 In the di-y and oj^en v/oods of western Pennsylvania and 

 New-York, in certain localities abundant. It is there 

 called Columbo-root, and appears to be a tonie no way in- 

 ferior to the Genticuia lutea. 



A genus peculiai'to tlie United States. 



152. OBOLARIA. Z. 



Calix 0, or in the form of 2 bract es. Corolla 

 campanulate, 4-cIeft, segments entire, (the mar- 

 gin somi'times crenately turn.) Stamina equal, 

 proceedins; from the clefts of the corolla. Stig' 

 ma emai'.^inatp. Capsule ovate, 1 -celled, 2-vaiv- 

 ed, many-seeded,- seeds minute. 



A very small vernal plant, with a simple stem, and op- 

 posite leaves; flowers sessile, terminal and marcescent, 

 collected by pairs or by llwees towards the summit of the 

 stem; stigma minutely biiid. (Bitter, and probably tonic.) 



Species. 1. O. virginica. I'erennial? abotit 3 or 4 

 inches higli, with a small branching root; leaves thick, 

 ^- green, almost carnose, frequently purplish on the un- 

 der side; flowers bluish-white, subtended by foliaceous 

 bractes. 



Peculiar to Nortli America. — In the neighbourhood of 

 Philadelphia, rare.— Dr. W. P. Barton. Near West Ches- 

 ter, (t'cnsylvania.) — Dr. W. Darlii^gton. Abundant in 

 the shady Vorests of Luke Krie, (Oiiio.) In the revision 

 and arrangement of this gmus, which distinctly apper- 

 tains to the Natural Oi'der G'e;j^/fine(fof Jussieu, lam hap- 

 py to have been corrDborated by the interesting remarks 

 of Dr. W. Darlingcon, who for four yeais in succession 

 %. has been in the habit of examining the Obolaria. 



ft Flowers tetrapetalaus* 



153. AMMANNIA. Z. 



Calix 1 -leaved, striate, 8-tootbed, inferior. 

 Corolla of 4 petals, or none, inserted upon the 

 calix. Capsule 4-celled, many-seeded. 



Subaquatic herbs with opposite leaves; flowers very 

 small, axillary, sessile, or shortly pedunculate, opposite, 

 and sometimes almost verticillate. In ^2. indica, and .i. 

 verticillatoy the calix is 4-toothed, and shorter than the 

 capwile. 



