POLEMONIUM REPTANS. 

 CREEPING GREEK VALERIAN. 



NATURAL ORDER. POLEMONIACE^E. 



PoLEMONiUM REPTANS, LinHDsus. — Smooth and succulent; branched and leaning; leaflets five 

 to eleven, usually seven to nine, mostly opposite, the terminal one lance-obovate, about 

 an inch long; common petiole half an inch to two inches in length below the leaflets, 

 slightly winged, pubescert-ciliate ; corymbs few-flowered, nodding; corolla blue, about 

 three times as long as the calyx; the lobes short, obovate, rounded. Capsule on a short 

 stipe, in the enlarged, persistent, veined, green, and somewhat membranous calyx. (Dar- 

 lington's Flora Cestrica. See also Gray's Manual of the Botany of the Northern United 

 States, Chapman's Flora of the Southern United States, and Wood's Class- Book of Botany.') 



HE Greek Valerians, known botanically as Polcmonhtm, 

 form a genus of great interest to the American student, 

 having been selected by Jussieu, one of the chief founders of the 

 natural system of Botany, as the type of the natural order Pole- 

 77ioniacca:. The original Greek Valerian, Polcmoniiini cwj-uleiun, 

 is a native of northern Europe and Asia; but it is also indige- 

 nous to our own country, and by far the greater bulk of the 

 whole order are American. Indeed, we may regard Polenioniacccr 

 as in the main an American order of plants. Botanists regard 

 them as somewhat allied in structure to the Bind-weeds or Con- 

 vohmlacccr — but they are very different in their aspect. On the 

 other hand, they have much the general appearance of the 

 Hydrophyllaceo' or "water-leaf" family, but differ essentially in 

 placentation, or manner in which the seeds are connected with 

 the ovarium. In PolemoniacccE the placenta is axile, while in 

 Hydrophyllacece it is central, in which case the seeds do not seem 

 attached to the sides of the capsule, but to a soft mass in the 

 centre. The two great genera of the eastern United States are 



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