95 



by the specific name conferred by Mr. Nelson rather than by 

 the varietal form proposed by Mr. Fernald. 



My own observations on the two plants were made near 

 Van Cortlandt, New York City, where both occurred near to- 

 gether in the same marshes, S. robustus mostly along muddy 

 ditches, S. pahidosus on the open salt meadows or along their 

 borders. I have since found .S". paludosus abundant on muddy 

 or sandy flats along the coast as far east as Mt. Desert. 



Not the least noteworthy distinction between the two plants 

 where they occur together is in their time of flowering, 6". 

 paludosus coming into bloom three or four weeks before its near 

 relative, sometimes being in full bloom while yet its companion 

 species shows not the first signs of developing spikes. I have 

 found it blooming as early as the third week in May, while the 

 spikes of S. robustus do not usually appear until towards the 

 middle of June. Furthermore S. paludosus often or usually 

 grows in close colonies, 6". robustus in scattered groups. My 

 field notes record the following comparative differences between 

 the two as they occur at New York : S. robustus is habitually 

 much taller and more leafy, mostly with longer and broader 

 leaves and stouter culms ; S. paludosus is lower and stiffer, with 

 much shorter and narrower leaves. It is in fact often extremely 

 slender throughout, and though becoming 6 dm. or more tall 

 often bears dense clusters of fruiting spikes when only a few 

 inches high. 6". robustus becomes 1.5 meters tall, and small ex- 

 amples are usually sterile or only imperfectly floriferous. The 

 dense clusters of mostly ovate, sessile spikes have already been 

 described by Mr. Fernald. In addition I find the scales to be 

 usually darker and relatively shorter, finally becoming more 

 lacerate and the achenes often also darker, thicker and more 

 broadly obovate or sub-orbicular, and the styles shorter. The 

 underground tuber-bearing stems also appear to be quite con- 

 stantly shorter than those of 5. robustus. 



S. paludosus has undoubtedly much the habit of S. campestris 

 Britton, of the prairie region, which is also rated by Mr. Fernald 

 only a variety of S. robustus. Of the perfect distinctness of .S". 

 campestris, however, I can feel no doubt after the examination of 

 fully matured examples showing a form of achene which in 



