68 Staten Island Association of Arts and Sciences 



serpentine ridge, the nearest station being at Oakwood, several 

 miles distant. Around the margin of the pool of water which yet 

 remains in the deepest part of the basin a dense stand of Typha 

 latifolia L. has become established (pl. i, /. 2), all the fertile 

 spikes of which are deeply constricted above the middle. I have 

 previously seen this character in isolated specimens but never 

 before as a prevailing feature of the species. This stand prob- 

 ably originated from seed blown from the few plants growing at 

 the upper end of the Clove valley. A number of seedlings of 

 Salix nigra falcata (Pursh) Torr. have also found a soil that 

 evidently suits them there, and their origin is somewhat problem- 

 atic, inasmuch as this variety has not heretofore been reported 

 from Staten Island and the species is not known elsewhere in the 

 vicinity. 



As an ecological subject of study Silver Lake basin has proved 

 to be of considerable interest. The ground exposed by the drain- 

 ing of the lake is virgin soil, so far as terrestrial and semiaquatic 

 vegetation is concerned, and the fact is significant that several 

 species new to our local flora, and others previously unknown, in 

 the vicinity, immediately established themselves there. Appar- 

 ently these plants had not heretofore found suitable soil condi- 

 tions in any of the adjacent marshy areas, or else these areas were 

 too densely populated by other species better able to prevail in the 

 struggle for exiistence. It would be interesting to note what the 

 dominant floral elements would be after a lapse of several years ; 

 but it is doubtful if existing conditions will continue through 

 another season. 



In order to obtain an adequate idea of the change that has 

 taken place in the flora during the past year the views selected to 

 illustrate this paper may be compared with certain of those used 

 to illustrate the first paper on the locality, previously mentioned. 

 Thus, figure i of plate i represents the present appearance of 

 the same portion of the lake basin as is shown in figure i, plate 

 2, volume 5, and figure 2 of plate i represents almost identically 

 the same point of view as figure 2, plate 2, volume 5. 



