90 TETRANDRIA, MONOGYNIA. 



in his late work (1817), Anlekung zur Kenntniss der Gewcichse, of 

 which I have been favoured with two volumes from the author, 

 lias boldly imposed the name Andrewsia, after Mr. Andrews, 

 the well-known author of a beautiful work on the Roses ; and 

 I have, without hesitation, followed him, for this reason, among 

 others, which doubtless actuated Sprengel in giving the new 

 name, that Centaurella, as the diminutive termination of Cen- 

 . taurium, a genus already established, is in direct violation of 

 the commonly received rules for botanical nomenclature : but 

 a more cogent motive is, that the name Banonia, formerly 

 given by Dr. Muhlenburg, may be entirely disused, as applied 

 to this plant. A splendid genus, first discovered by Mr. 

 Nuttall on the borders of the Missouri, he has, with a very 

 honourable sense of the genius, learning, and botanical attain- 

 ments of the late Professor Barton, dedicated to him ; in which 

 name Mr. Pursh acquiesced, and published in his Flora. 



Andrewsia panicuiata is easily recognized by its nearly sim- 

 ple, upright, rigid yellowish stem, and inconspicuous whitish 

 flowers. It grows among mosses, and particularly among 

 sphagnum, in the cranberry-swamps of Jersey. It is not very 

 frequent; and on the Pennsylvania side is more rare. It de- 

 lights in shade, moisture, and retirement. Annual. September. 



83. OBOLARIA. Gen. pi. 1044. (Gentian*.) 



Calix 0, or in the form of 2 bractes. Corolla 

 campanulate, 4-cleft, segments entire, (the 

 margin sometimes crenately torn.) Stami- 

 na equal, proceeding from the clefts of the 

 corolla. Stigma emarginate. Capsule ovate, 

 1-celled, 2-valved, many-seeded ; seeds mi- 

 nute. — Nutt. 



Vh'simca. 1. O. stem simple ; leaves oblong truncate, fleshy, 

 purple underneath ; flowers axillary solitary, ses- 

 sile. — Wiitd. and Pursh. 



Icon. Pink. aim. t. 209. f. 6. 



A very beautiful and interesting little plant, seldom attaining 

 a greater height than three inches. Root branching. Leaves 

 opposite, apple-green above, pale purple underneath, some- 

 what fleshy. Flowers collected by pairs or threes towards the 

 top of the stem; they are of a skimmed milk-white colour, 

 and form, with the numerous conspicuous, purplish bracteas, 

 a delicate and pleasing contrast. The whole plant has the 

 appearance of an artificial wax flower. Very rare. On the 

 high banks of the Wissaluckon, about three quarters of a mile 



