TERMS. 



Most of the terms used are those common to Botanical des- 

 criptions, but those referring to the venation may be so unfa- 

 miliar as to require definition. They are based on a most excel- 

 lent paper by Dr. Glatfelter (Rep. Mo. Bot. Gard 5:46-60. 1894.) 

 on the venation of the willows. 



Primary. A main vein branching directly from the midrib. 



Costal. A smaller vein from the midrib, of considerable 

 size but not reaching as far as the primaries. 



Secondary. A vein of the second order given off from a pri- 

 mary. 



Tertiary. A vein given off from a secondary. 



Arch. The joining near the margin of a primary with a 

 fork sent off from the one next above, the two branches together 

 forming the arch which rests upon the two primaries. 



Loop. Formed by a primary near the margin curving 

 forward and inward and merging into the next above, similar 

 to an arch but lacking the angle at the apex. 



Regular. Veins parallel. 



Bract. 1 In his treatment of the genus in Britton's Manual 



Scale, j Mr. P. A. Rydberg applies the term bract to the 

 rudimentary perianth of the flower, a small leaf subtending the 

 essential organs, whereas previous writers have termed this a 

 scale and reserved the former term for the bracts which support 

 the aments. This departure from the accepted usage seems to 

 me almost as confusing and unjustifiable as the departures from 

 the rules of priority in nomenclature which the New York Botan- 

 ists condemn so strongly. Further the meaning given the terms 

 in the glossary at the end of the book, accords better with the 

 older usage than with Rydberg's application of them. Those 

 definitions are here followed. According to Britton, a "Bract" 

 is "A leaf, usually small, subtending a flower or a flower cluster 

 or a sporange. " That is, in this case one of the leaves which ap- 

 pear at the bases of the aments. And a "Scale" is "A minute 

 rudimentary or vestigial leaf." — In this case one of the small 

 leaves in the axils of which the flowers are borne. To make the 

 matter worse, Rydberg uses bract in both senses thus introducing 

 ambiguity also. 



