l8 9i] Briefer Articles. 117 



grow." I was unable to decide whether the young plants sent out 

 runners as soon as they were well rooted, but there were some indica- 

 tions that such was the case, as they became densely crowded in places 

 where apparently there were but few specimens in the beginning. If 

 there were such runners they soon disappeared and the plants stopped 

 sending them out Two other possible explanations suggested them- 

 selves to me; one, that such part of the stems of the old plants as were 

 well covered with mud retained their vitality much longer than those 

 not so protected, and appeared like runners, as the surface of the mud 

 became drier and shrunk away; the other, that part of these young 

 plants were seedlings, but if they were such their growth was exceed- 

 ingly rapid, for the plants in given clusters were very nearly of the 

 same size. At the date given above, the axes of the plants had not 

 increased materially in length. The leaves were practically all radical 

 and because of the crowded condition of the plants, long petioled. 

 Shortly after the middle of September the fall rains set in, and water 

 began to collect again in the ponds. At this time the stems began to 

 grow, at first with very short nodes, but later, as the water became 

 deeper, with longer ones. The greater number of plants sent out 

 branches from the nodes of the stem even when the internodes were 

 short. As the water grew deeper during the fall, the leaves which were 

 submerged died and new ones, more finely cut, replaced them, and 

 by the time the plants were entirely covered the foliage was as finely 

 dissected as that of the aquatic flowering form. On the 18th of Oc- 

 tober I found two plants in bloom. The water had hardly reached 

 them and the stems were trailing with rootlets projecting from the 

 underside of the nodes. The leaves of these specimens were petiolate 

 and between the dissected form of the aquatic plant and the cleft and 

 parted form characteristic of the terrestrial plants of the summer. The 

 flowers were somewhat smaller than the usual aquatic ones. On my 

 last visit made late in November, just as the ice was beginning to form, 

 1 found that the depth of water in the ponds had materially increased 

 and that the submerged plants had made strong and rapid growth, and 

 were entirely typical in foliage and other particulars. The summer 

 leaves were all dead and brown, while the new ones were green and 

 vigorous. Some plants which I had transplanted above high water 

 mark, were still living, but showed no marked growth as in those 

 under water, and the leaves were unchanged. From these considera- 

 tions, if we consider the observed conditions of growth and propaga- 

 tion normal, and there is no evidence to the contrary, our plant is 

 truly perennial, since the old stems live long enough to nourish and 

 thoroughly establish the plantlets which develop at their node> 



