612 BIcKNELL: FERNS AND FLOWERING PLANTS OF NANTUCKET 
PENNSYLVANIA: Smithville, Lancaster County, J. K. Small & 
Io Fe Carter. 
MARYLAND: Hyattsville, Aug. 13, 1904, H. D. House. 
NorTH CAROLINA: Mica, June, 1898, C. W. Hyams. 
In herb. Columbia University: 
New York: Springfield, L. I., 1896, Elizabeth G. Knight; 
New Dorp, Staten Island, Aug. 31, 1890, N. L. Britton. 
SAROTHRA GENTIANOIDES L. 
Abundant in dry sandy places, stems appearing June 15, 1911; 
in full flower in September. The plant may be actually minute, 
its simple stem bearing only a single flower, or densely branched 
to form a firm convex mass I-1.5 dm. in diameter. 
TRIADENUM VIRGINICUM (L.) Raf. 
Very common in wet swamps and about the borders of muddy 
ponds. Earliest leaves May 31, 1908; no flowers remaining in 
September. 
ELATINACEAE 
ELATINE AMERICANA (Pursh) Arn. 
Common in some of the sandy ponds, growing in shallow water 
near the shore.. Observed especially in Maxcy’s Pond, Miriam 
Coffin Pond, and Miacomet Pond. At Maxcy’s Pond on Sept 
12, 1907, it grew as profusely on the damp sand where the water 
had receded as beneath the surface along the shore. At one spot 
in heavy mud ten yards or more from the water’s edge it had 
formed compacted moss-like mats, some of them six inches across, 
a mode of growth remarkably unlike that of the submerged plant. 
Correlated with this difference in habit ran a variation in characters 
which was brought out strikingly by comparison of the living 
plants. In water and on damp sand the individual plants were 
separate in growth, uniformly simple-stemmed, and whitish or 
pale green in color. In the mud form the matted stems were often 
divergently much branched and the general color a lively green 
tinged with reddish or purple, these tints deepening on the cap- 
sules into bright crimson; instead of greenish white the petals 
were rose color and were sometimes as large as 1.5 mm. in breadth. 
The capsules, some being four-valved, were larger than those of 
