1904] Brainerd, — Hybridism in the Genus Viola 219 



are so closely allied that they might without much impropriety be 

 regarded as phases of one species. 



4. Viola affinis x septentrionalis. — My first and most im- 

 portant station for this is Knight's Island in northern Lake Cham- 

 plain, on which I have camped in summer for many years, and whose 

 two hundred acres I have thoroughly explored. I never observed 

 there but two species of blue stemless violets, V. affinis and V. sep- 

 te?itrionalis ; but these grow in abundance in moist thickets of arbor- 

 vitae, under old appletrees and in moist meadow-land. While 

 studying these species critically in August, 1903, I was perplexed to 

 find several specimens that I could not satisfactorily place in either 

 category. The leaves were too acuminate and narrow for K septen- 

 trionalis^ but not sufficiently so for V. affinis ; there was a slight 

 pubescence on the petiole and on the margin of the leaf and on the 

 auricles of the sepals, such as V. affinis never had, but not enough 

 pubescence for V. septentrio?ialis. What added to my embarrassment 

 was the fact that I was totally unable to find plump, full grown cap- 

 sules, though there were plenty of small seemingly immature ones. 

 I carefully weeded and mulched the large clump that I had left 

 growing, and waited for further developments. I visited the station 

 last May and frequently during the following July, and became thor- 

 oughly satisfied that the plant was a hybrid between the two species 

 so common on the Island. 



A further incident is of interest, as sliowing that the seeds of this 

 hybrid, though few, are fertile and will produce vigorous plants. 

 When I finally on July 24th dug up the clump for herbarium speci- 

 mens, I found thirty-three seedlings closely clustered about its roots, 

 bearing each only one or two leaves. These seedlings I carried home 

 and planted ; they have all lived and fiourished. Many of them 

 produced in September cleistogamous capsules ; but all of the cap- 

 sules show the same paucity of seeds as those on the mother plant. 

 I found several specimens of this hybrid last May in an open 

 grove of sugar maples near Middlebury. The ground was gay with 

 the large violet flowers of V. septentrionalis, and in the moister hol- 

 lows of the ledge there was an almost equal profusion of V. affinis. 

 Careful search revealed intermediate forms. One of these trans- 

 ferred to the garden has produced more than fifty capsules, all show- 

 ing the characteristic infertility of the hybrid. 



I have collected a few specimens of the same thing at a third 



