192 IRIS VIRGINICA. BOSTON IRIS. 



water stands In them in winten All the authors who mention 

 it, speak of it as growing in wet or muddy places, with the excep- 

 tion of Mr. Ruger, who, in a note to the " Bulletin of the Torrey 

 Botanical Club," in- the volume for 1875, says that it grows on 

 rocks at New Durham, In the State of New York, in company 

 with Sileiie injlata. But whatever may be the circumstances 

 under which it is forced to exist in a state of nature, there Is no 

 doubt that it prefers dry, rich garden ground to the swampy 

 places In which it is originally found. Our Boston Iris is, in- 

 deed, one of the prettiest of cultivated plants. It blooms in 

 June, and the flowers follow one another In close succession, 

 keeping up the display for several weeks. The flowers produce 

 seed in great abundance, and seedlings could no doubt be easily 

 raised, but the plants can be propagated more readily by divid- 

 ing the rhizomas or creeping stems. In English gardens our 

 species was under cultivation before the year 1758. 



The fertilization of the plant Is a very interesting process to 

 the student. From the arrangement of the stamens and pistils, 

 it might be supposed that its pollen cannot reach the stigma 

 without external aid. But the writer of this, for the purpose of 

 keeping off the insects, placed fine gauze bags over some flow- 

 ers which were about to expand, and yet these flowers produced 

 perfect seed as well as those which had not been protected. We 

 can infer from this that there Is something still to be learned In 

 regard to the fertilization of our species. 



The flower stem has a much more branching character than 

 the size of our page would permit us to show, but the peculiarly 

 wavy or twisted growth of the branchlcts, which, together with 

 the delicate, narrow leaves, is very characteristic of this species, 

 is well shown on the plate. 



Our drawing; is from a Massachusetts specimen, kindly fur- 

 nished by Mr. Jackson Dawson. 



Explanation ok the Plate.— i. Rhizoma, with a primary and secondary terminal growth, 

 from the latter of which the flower-stem will grow the next year. — 2. Branchlet, show- 

 ing flower in bloom with an unopened bud. 3. — ]5ranchlet, showing that the first ilower 

 is faded before the second is ready to expand. — 4. Cross section of the ovary. 



