CONOVER ON ASPARAGUS PLUMOSUS. 63 



ASrAEAGUS PLUMOSUS. 



L. LENORE CONOVER. 



Asparagus plumosus grows from the seed and during the first year 

 forms a croAvn which sends up primary stems bearing branches with 

 scale leaves and Cladophylls or false leaves. When grown in five-inch 

 crocks for the first year or two, the stems attain a maximum length of 

 thirty-eight to forty-five cm. This stage of the plant exhibits a habit of 

 growth which first called out questions for investigation. Each of the 

 primary stems is orthotropic, or erect, until it attains a height of from 

 twelve to twenty-five cm., according to the vigor of the growth, when 

 it curves to the horizontal and the uj)per portion becomes a dorsi-ventral 

 member. Lateral off-shoots do not develop until the primary stem 

 has approximately attained its full length and established its curve, 

 but these branches, whether above or below the curve, always assume 

 the horizontal position; in fact, stem, branches, and cladophylls take 

 the common horizontal plane w'hich becomes permanent for all except- 

 ing the cladophylls. As the plant grows older the cladophylls may form 

 radiating clusters at each node. 



When transplanted to a rich bed of earth the roots form a flat mat 

 near the surface, evidently to obtain the surface organic matter. The 

 crown then sends up more and more vigorous growths, some of which 

 become twining stems of various heights. Under ordinary conditions 

 the twiners grow from five to seven feet high but under special cultiva- 

 tion in old plants they may grow thirty feet high. 



The questions to which I gave my attention under Dr. Newcombe's 

 direction are: 



1. What are the directive agents of the dorsi-ventral organs? 



2. Are the branches sensitive to the same stimuli and in the same 

 degree as the stem? 



3. Is there a morphological upper and lower side which is permanent? 



4. Xutation and circumnutation of the erect and horizontal stems. 



5. To determine the phenomenon and conditions of climbing; whether 

 the stem is sensitive to contact; and the dependence of climbing on the 

 general vigor of the plant. 



I reviewed literature on the subject of dorsi-ventral or plagiotropic 

 plant organs and although there was no mention of this plant, I could 

 not but note the variety of conclusions reached by investigators as to 

 the causes of this horizontal grow^th. 



By experimenting with the plant in various positions, i. e., on one 

 side with the vertical portion lying horizontally and the horizontal por- 



