19 



I. Composition. 



1. SIMPLE, (simplex^) without divisions. 



2. COMPOUND, (compositus) when a common petiole 

 gives origin to several PARTIAL PETIOLES, which either 

 support leaflets immediately, or divide into other par- 

 tial petioles, Ex. Locust, Robinia, arid Sumach. 

 Ehus. 



II. Appendages. 



1. BEARING TENDRILS, (drrAi/br.) Ex. Common 

 Pea. 



2. WINGED, (alatus) furnished on each side with a 

 leafy appendage. Ex. Dwarf Sumach, Ehus copalli- 

 num. 



III. Form. 



1. ROUND, (teres.) Ex. Common Hollyhock. 



2. HALF-ROUND, (semiteres.) Ex. Yellow Water 

 Lily, JVjjrtipKcetl advena. 



3. FLATTENED, (compressus.) Ex. Lombardy Pop- 

 lar, Populus dilatata. 



4. CLUB-SHAPED, (clavatus) growing gradually 

 thicker towards the top. Ex. Cacalia suaveolens. 



IV. Direction. 



1. ERECT, (eredus] nearly perpendicular. 



2. SPREADING, (patens") forming an acute angle 

 with the stem. 



3. RECURVED, (recurvatus) curved downward. 



4. CLIMBING, (scandens) performing the office of a 

 tendril. Ex. Virgin's bower, Clematis Virginiana. 



Observation. 1. In length, the petiole is compared with the leaf, 

 as the peduncle is with the flower. See p. 18. 



2. Several terms, defined under caul-is, are occasionally applica- 

 ble to the leafstalk. 



6. Frond. 



FROND, (/rons.) PL 2, fig. 8. A species of trunk in 

 which the stem, leaf, and fructification are united as in 

 the Ferns, Filices. 



