THE LEAF. 



The parts of a leaf are the stipules, the petiole, and the blade. 

 The absence of either the first or the second of these parts is ex- 

 pressed by the terms, " exstipulate " and " expetiolate. " 



The general characters of a leaf (blade), so far as its gross 

 anatomy is concerned, pertain to its (i) venation, (2) form, (3) 

 sitrface and (4) texture. 



Each student is expected to select leaves illustrating the charac- 

 ters indicated by the following terms, and sketch them in the 

 same order in which the terms are given, emphasizing the charac- 

 ters indicated by the terms. 



I Venation. 



1. Palmately netted. 3. Palmately parallel. 



2. Pinnately netted. 4. Pinnately parallel. 



II. Form. 



There are several lines of difference among leaves as to form. 



A. General Outline. 



(a) Leaves tapering, if at all, from the middle tbWatd each end 

 I. e. , widest at the middle. 



1. filiform. 4. oval. 



2. linear. 5. oblong. 



3. elliptical. 6. orbicular. 



(b) widest toward the base. 



1. subulate. 3. ovate. 



2. lanceolate. 



(c) widest toward the apex. 



1. oblanceolate. 3. obovate. 



2. spatulate. 

 B. Apex. 



1. acuminate. 6. cuspidate. 



2. acute. 7. aristate. 



3. obtuse. 8. retuse. 



4. truncate. 9. emargiuate. . 



5. mucronate. 10. obcordate. 



