252 THE PI.ANT WORI.D 



Briefer Articles. 



PROPAGATION BY PETIOLE BUDS. 



In September, 1898, while collecting algae along the north branch of 

 the Chicago River I found a phaenogamous plant growing in the mud, 

 which I hoped might be made to grow in an aquarium. I placed it there 

 and a few days later noticed that four or five of its lower leaves had 

 dropped upon the water and had developed plantlets at the base of their 

 petioles. Other leaves fell which likewise developed plants. I then 

 pulled off leaves, hit or miss, and searched with a lens for a rudimentary 

 bud but failed to find one. Placing these leaves in water they soon de- 

 veloped young plants, as in the instance just mentioned, at the base of 

 the petiole where it had been torn off from the stem. 



A dozen of these plantlets thus started in water were transferred to 

 moist soil and placed under glass and allowed to develop in the hope that 

 the species might be satisfactorily determined. Their growth was observed 

 for nearly a year. For three months they were living in open garden soil. 

 But the experiment proved a failure, all the plants dying before a flow- 

 ering stem could be produced. So far as one could judge from leaf form 

 and arrangement the plant may have been a species of Lobelia, probably 

 L. Kahili L. 



The interesting point to which I would call attention is that here we 

 have a plant growing by the riverside, upon the flood plain, which by the 

 dropping of its leaves when its environment is disturbed may be propa- 

 gated by adventitious buds at the base of the petiole and distributed by 

 the flotation of these budding leaf -stalks to new localities. 



Buds do not arise from these leaves otherwise than at the base of the 

 petiole even though the leaf be cut or injured to induce their develop- 

 ments, as is commonly done with the leaves of begonias. 



C. B. Atwell. 



HYBRIDIZATION IN THE HONEY LOCUST. 



The Honey Locust, while nowhere abundant, is found here in almost 

 all situations, from the poorest, dry est hill sides to the richest alluvial 

 bottom lands. Within these variations of surroundings there grow many 

 different types of this species, from a low, spreading, useless, short-bodied 

 tree, to a majestic forest giant over 150 feet high, with a trunk clear of 

 branches 40 to 70 feet. In the former condition the bark is close and 

 inclined to be smooth, while in the latter the bark becomes more rough 

 and broken into large flakes, similar to those of the Shag-Bark Hickory. 

 In this last form there are few thorns, while in the upland form the body 



