THE KANSAS UNIVERSITY 

 SCIENCE BULLETIN. 



Vol. X, No. 9.] January, 1917. [ Zl^Tx^Tl 



Ecological Morphology of Abutilon theophrasti. 



BY LOUISE LUCKAN. 



ABUTILON THEOPHRASTI, commonly known as velvet 

 leaf, is an upright-growing mallow which may attain the 

 height of six feet. It thrives at the edge of cultivated fields or in 

 rich waste lands, such as lots, where it often occurs in dense 

 patches. 



During the summer of 1916 drought conditions prevailed for a 

 month. The last rain of early summer fell about Jime 28 or 29, 

 and the drought was not broken until the 26th of August. This 

 meant that plant life would probably suffer for lack of water for 

 at least a month. Many plants showed the effect of this lack of 

 moisture very much, but Ahutilon theophrasti remained fresh and 

 gi'een and attained its normal height. Here, then, an interesting 

 problem offered itself as to what provisions the plant had made to 

 withstand the drought. 



The material for this study was collected on the south slope of 

 the University campus. Both preserved and fresh material was 

 studied. The standard histological methods were used and the 

 drawings were made by the use of the camera lucida on the mi- 

 croscope and with the projectoscope. 



ANATOMY. 



The Leaf. 



The leaves, borne on long, slender petioles, are roundish heart- 

 shaped with an acuminate apex, and when full grown measure 

 from four to five inches across. When the leaves are picked off 

 they soon wither. During the hottest part of the day the edges of 

 the leaf curl, but it requires only a short time for leaves to regain 

 their turgor. 



(219) 



