82 MINNESOTA BOTANICAL STUDIES. 



Cornus florida Linn. 

 Seedlings of the " flowed ncr doofwood " resemble those of C. 

 amonuc7n. 



STYRACACE^. 

 Mohrodendron carolinum (Linn.) Britt. 



Seeds of this plant, the "snow-drop tree," planted in the 

 spring of the year following their ripening lie dormant an entire 

 year before germinating. 



The cotyledons are thin, oval-oblong in outline, rather short- 

 petiolate. The blades are at first 20 mm. long and 8 mm. 

 broad. They do not increase much in size. The hypocotyl is 

 stout, from 25-35 mm. long. 



The epicot}^ is about 20 mm. long. The leaves are all alter- 

 nate, ovate-acute, serrate, petiolate. Save in size there is no 

 difference between the first and the later leaves. 



BIGNONIACE^. 



Tecoma radicans (Linn.) DC. 



This is a woody climber, the "trumpet creeper," indigenous 

 to eastern North America and frequently cultivated. The seeds 

 germinate in about ten days. The large flat wing of the seed 

 is sometimes, though not usually, carried up. 



The cotyledons are broadly orbicular and deeply notched at 

 the apex. They are almost sessile. When first above ground 

 they are 5 mm. wide, but when fully open are 9 mm. wide. 

 They do not increase in size after that time. The hypocotyl is 

 20-30 mm. long, green or pale, sometimes pinkish. 



The epicotyl is at first quite short, but lengthens, when the 

 foliage leaves open, to about 15 mm. The first leaves are 

 simple, ovate, dentate, petiolate, distinctly veined. The next 

 leaves are tri-foliate. Leaves at length are pinnately com- 

 pound. 



Catalpa speciosa Warder. 



This large tree is a native of the southern United States. 

 Seeds germinate in from one to two weeks. The flat winged 

 seedcoat is sometimes carried up, but more usually remains in 

 the soil. 



The cotyledons are face to face. They are dark green, 



