846 REPORT OF STATE GEOLOGIST. 



PASSIFLORACE.E. Passion Flower Family. 

 PASSIFLORA L. 



P. lutea L. Yellow Passion Flower. 



Found only in a few localities in the southern counties. Mr. 

 Blatchley reports it from four stations in Monroe County, and 

 Dr. Hessler as rare in Fayette County. I have found it on a sin- 

 gle hillside in Jefferson County, trailing over limestone rocks. In 

 Monroe County it is found on hillsides and in thickets. In our 

 area it is a lime soil plant. 



It blooms somewhat sparingly during June, July and the 

 earlier part of August, and is one of the most delicate and grace- 

 ful members of our flora. 



Gibson. 



CACTACE.E. Cactus Family. 

 OPUNTIA Mill. 



O. humifusa Raf. Western Prickly Pear. 



(0. Rafinesquii Engelm.) 

 This is the only member of the Cactus family within our 

 bounds. It is found in great abundance in the northwestern cor- 

 ner of the State in dry sand. In July and August its large yellow 

 flowers (two to four inches broad), and prostrate, deep green stem, 

 make it a marked feature. The Pennsylvania Railway is skirted 

 for-miles with this unique form. In 1885 it w r as found at Lafay- 

 ette Junction, in Tippecanoe County, by Dr. Barnes, but failed 

 to maintain itself. It was also reported from near Attica, Warren 

 County, but a visit to the locality showed that if it had been 

 present it had not maintained itself beyond a single season. It 

 seems to be spreading somew T hat along the line of several rail- 

 ways entering Chicago, but will probably not extend permanently 

 beyond the sand covered region. 



THYMELEACEJE. 

 DIRCA L. 



D. palustrts L. Leather-wood. Moose-wood. 



A well known shrub, flowering in April and May. While found 

 in many parts of the State it is nowhere abundant, and is in some 

 places rapidly disappearing. The cause of its failure to maintain 

 itself has not yet been made out. The plant is poisonous, the 

 poison being very abundant in the bark. Applied to the skin, the 



