112 Botany of Illinois and Missouri. 



Art. XVII. — Contributions towards the Botany of the States 

 of Illinois and Missouri ; by Lewis C. Beck, M. D. 



(Continued from Vol. XI, p. 182.) 

 ICOSANDRIA. MONOGYNIA. 



Cactus opuntia. Lin. 



Hab. Sandy banks of the Illinois river, near Fort Clark, 

 frequent. 



Prunus pennsylvanica. Ait. 



Hab. Barrens, near St. Louis — May. 



Obs. Lower surface of the leaves somewhat pubescent, 

 their shape usually oblong-oval. Pedicels about an inch long, 

 smooth. This species can be readily distinguished from P. 

 americana. Marshall. (P. nigra. Ait?) by the serratures 

 of the leaves which in the latter are very sharp, — almost spi- 

 nose. 



Lythrum alatum. Pursh. 



Hab. Marshes, four miles west of St. Louis — June. 



Obs. Stem two to three feet high, winged. Leaves close- 

 ly sessile, sub-cordate, ovate-oblong, opposite, and alternate. 

 Flowers hexandrous, solitary, longer than the leaves, sessile 

 or on very minute pedicels. 



ICOSANDRIA. DI PENTAGYNIA. 



Agrimonia eupatoria. Lin. 

 Hab. Prairies near St. Louis, frequent — July. 



Agrimonia suaveolens. Pursh. 



Hab. Borders of marshes near St. Louis — July. 



Obs. Stem one and a half to two feet high, densely cov- 

 ered with long brownish hairs. Leaves interruptedly pin- 

 nate ; leafets thirteen to fifteen, with smaller ones interpos- 

 ed, terminal one sessile, all more or less hairy beneath. 

 Flowers small, and nearly sessile. 



Crata3gus crus-galli. Ait. 

 Hab. Prairies near St. Louis — April. 



Crataegus coccinea. Lin.? 

 Hab. Alluvions of the Illinois — April. The confusion 

 which attends this genus leaves me in doubt concerning this 

 plant. 



