36 REPRESENTATIVE PLANTS 



in very early spring : Strawberry, five-finger, yellow straw- 

 berry {ijotentilla sp.), rose, clover, all divided forms, besides 

 which various toothed and lobed leaves may be vised, pref- 

 erably oaks, which as dry leaves are present all winter. 



Special leaves. Examine each leaf furnished, determine 

 the method of division (palmate or pinnate), the amount of 

 division, and the features of the leaflets. Examine for 

 stipules. Draw each leaf, showing all the features. 



A leaf discussion will follow later, but determine at this 

 point, if you can, the value to the plant of divided leaves. 

 Is it a common feature or not ? Is it more abundant among 

 herbs or among trees ? Some reasons for this may appear 

 later. 



General terms. Many terms are in use, especially in the 

 older editions of our botanical textbooks, expressing all 

 degrees of variation in form and amount of division, but 

 the following seem sufficient for the purpose of the aver- 

 age student : (1) Entire margin (lilac) ; (2) serrate margin 

 (willow) ; (3) dentate margin (catnip) ; (4) crenate margin 

 (5) lobed margin (oak, maple) ; (6) cleft margin (hemp) 

 (7) trifoliate leaf (clover) ; (8) quinate leaf (five-finger) 

 (9) odd pinnate leaf (locust) ; (10) even pinnate leaf 

 (11) decompound leaf (yarrow) ; (12) ternately divided leaf 

 (meadow parsnip) 



4. Winter and Spring Rosettes and Leaf Mosaics. 

 Leaf Arrangement 



Material. Rosettes are very easily obtained in the late 

 fall or early spring, from mullein, shepherd's purse, thistle, 

 evening primrose, and five-fingers. A growing plant of 

 begonia, geranium, or primrose in a window will do well to 

 show the mosaic arrangement on the stem. For many pur- 

 poses, specimens mounted on bristol board behind glass are 

 admirable for this work, and, in truth, for practically all the 

 study of ordinary leaves. 



