240 GENTIANACE^E. 



Style erect. Stigmas 2, roundish. Capsule linear, 1 2-eelled, 

 2-valved. Seeds minute. 



1. E. Centaurium Pers. : stem erect, nearly simple ; leaves ovate-oblong, 

 nerved ; flowers subsessile, fasciculate-cymose ; calyx half as long as the 

 tube of the corolla. Chironia Centaurium Wittd. 



Dry grounds. Near Oswego, and in Putnam county, N. Y. ; rare. July, 

 Aug. (J). Stem 8 12 inches high. Leaves variable ; the lower ones broader 

 than the upper. Flowers rose-color, in fasciculate cymes near the top of the 

 stem. Common Centaury. 



2. E. MMenbergii Griseb. : stem simple or branching ; leaves ovate-ob- 

 long, somewhat obtuse ; flowers in loose dichotomous cymes, the central ones 

 pedicellate ; corolla after flowering twice the length of the calyx ; the lobes 

 oblong-lanceolate. (D. C.) E. pulchella Darlingt. 



Wet meadows. Flushing, N. Y. Torr. Penn. and Virg. Darlingt. July. 

 3D- Stem 2 6 inches high, sharply 4-angled. Flowers smaller than in the pre- 

 ceding ; limb bright-purple. It is perhaps not distinct from the preceding. 



Muhlenberg's Centaury. 



7. EXACUM. Linn. Exacum. 



(From the Latin ex, out, and ago, to drive ; it being supposed to have the 

 power of expelling poison from the stomach.) 



Calyx deeply 4-parted. Corolla 4-lobed, with the tube glo- 

 bose. Stamens 4. Style 1. Stigma 2-cleft. Capsule bi- 

 sulcate, 2 -celled, many-seeded. 



E. pulchellum Pursh : lower leaves roundish, the rest subulate ; panicle 

 corymbose ; peduncles filiform ; calyx 4-parted, segments subulate. Cicen- 

 dria pulchella ? Griseb. in D. C. 



Sea coast, N. J. ; rare. Aug. (J). Flowers small, rose-color. 



Pretty Exacum. 



8. CENTAURELLA. Mick. Centaurella. 

 (A diminutive of Centaurea.) 



Calyx 4-parted, appressed. Corolla subcampanulate, 4- 

 parted ; segments somewhat erect. Stamens 4. Stigma thick, 

 glandulous and partly bifid. Capsule 1 -celled, 2-valved, many- 

 seeded, surrounded by the persistent calyx and corolla. 



C. paniculata Mich. : stem somewhat branched, smooth ; peduncles op- 

 posite, the lower ones branched ; leaves minute, subulate, alternate below, 

 nearly opposite above ; flowers in panicles ; corolla as long as the calyx ; 

 style very short. C. autumnalis Pursh. Bartonia tenella Muhl. 



Damp grounds. N. Y. to Car. Aug., Sept. (1). Stem 48 inches high, 

 square, often twisted. Leaves scarcely 2 lines in length. Flowers small, green- 

 ish-white, on the ends of the branches. Late-flowered CentaureUa, 



