82 THE AMERICAN BOTANIST. 



the stem they are leaving and a tendency to grow perpen- 

 dicularly upward. In the hardwoods the white oak seems to 

 be the most successful in driving its lower branches out hori- 

 zontally, which gives a particularly sturdy appearance. — El- 

 wyn Waller,, Morristozvn, N. J. 



Cleavage Planes of Smilax. — The common green 

 briar or cat briar {Smilax) of low thickets and fence rows 

 is uique in several respects. For one thing it, and the other 

 species of the genus, are the only woody monocotyledons in 

 the Northern States and in some places comes near to com- 

 peting with the yucca for the title of the only evergreen 

 monocot. Late in the year the green briar reluctlantly drops- 

 its leaf blades and then we discover that unlike monocots in 

 general it has developed cleavage planes to assist in getting 

 rid of them. It is interesting to know that monocots can de- 

 velop cleavage planes when necessary and still more interest- 

 ing in this particular case to discover that the plane is not 

 developed where the leaf joins the stem of the plant as in 

 most species, but occurs where the leaf-blade joins the petiole 

 and leaves the latter as a short hard stub guarding the lateral 

 bud all winter. It is possible that this protection to the bud 

 is one of the reasons why the petiole is not cut off, but the 

 most important is evidently the fact that the stipules act as 

 tendrils and to cut off the whole leaf would leave the plant 

 without support. 



Curious Forms of Gaillardia. — On the prairie of the 

 middle west and extending into Louisiana and Texas grow 

 several species of showy composites that have been introduced 

 into cultivation under the name of blanket flower. Some of 

 the species are annual and others perennial, but from various 

 indications it is likely that those cultivated may be hybrids. At 

 any rate they are among the showiest of our garden plants be- 

 ginning about mid-June to put up large daisy-like heads whose 

 rays are bright yellow at the tips and deep red at the base. The 



