VEINS. 



87 



a. In our description of individual forms, we shall select only the most remark- 

 able, leaving others for explanation in the Glossary. 



The most obvious arrangement is that which is founded upon the modes of the 

 veining ; but it should be premised that different forms of venation often give rise 

 to the same outline. 



232. Of FEATHER-VEINED leaves, the following forms depend 

 on the length of the veinlets in relation to each other, and to the 

 mid vein. If the middle veinlets are longer than the rest, the leaf 

 will be 



1, Orbicular (roundish), as in Pyrola rotundifolia. 



FIG. 29. Figures of feather- veined leaves. The numbers refer to paragraphs, a, deltate 

 leaf of Populus. 



2. Elliptical (oval), as in Lespe^eza prostrata; or 



3. Oblong (narrow-oval). Ex. Arenaria lateriflora. 



If the lower veinlets are longer than the rest,the leaf will be 



4. Ovate (egg-shaped), as in the Mitchella repens, or 



5. Lanceolate (lance-shaped), narrow, and tapering to each 

 end. Ex. sweet-william. 



When the veins are most developed towards the summit of 

 the leaf, it becomes 



6. Obovate (inversely egg-shaped), as in the walnut; or 



7. Spathulate (shaped like a spathula), as in the daisy. 

 Again, if the lowest veinlets are longest, sending off veinulets 



backwards, the leaf will be 



8. Cordate (heart-shaped), like the ovate fcirm, with a hollow 

 (sinus) at the base, as in the lilac. 



9. Auriculate, having ear-shaped lobes at the base. Ex. 



sage. 



8* 



