88 THE RELATION OF PLANTS TO TIDE-LEVELS 
and the general scattered distribution of the plant is indicated by that shown for 
a typical area on plate VII B. 
On the west shore Limonium has been found at only three points, all of which 
are artificially gravelly areas. A few plants are at 750 north, on a dilapidated 
boat-landing. About a dozen specimens were found at 1,070 north and the 
same number at 2,090 north. 
At the Spit, Zimonium is most abundant on the western quarter of the south 
shore (plates v, X B, XII, and xv). In the broad band of Spartina patens here 
between 700 and 900 north several dozens of this species are scattered, sometimes 
4 or 5 ina square meter. On the eastern half of the Spit, Lamonium is scattered 
very sparsely; ¢. g., only 10 plants were found between 0 and 260 east. Beyond 
this, eastward to 840 east, the plants may be locally somewhat more abundant, 
but on the whole they are evenly scattered, and not more than 100 plants are 
present altogether on this half. 
The large majority of the plants of Iimonium about the whole harbor are 
found between the 6.75 and 7.75 foot levels. On well-drained peaty soil, such 
as turfs of Spartina patens, Limonium may get down to 6.5 feet, while on hard, 
gravelly beaches, out of reach of fresh water, it may go up to 8 or, in one 
instance, to 8.25 feet. It is found only in sunny situations. 
Plantago decipiens on the upper littoral belt: This narrow-leafed fleshy 
perennial is found in this belt at three or four points about the head of the 
harbor, on gravelly or half-drained peaty soils between the 6.25 and 8.25 foot 
levels (160 south by 1,090 east, 400 to 480 north by 1,040 east, and 20 south 
by 730 east, etc.) (plate x11). It is rather surprising that this plant has not 
been seen on some of the gravelly beaches of the Spit and west side of the harbor, 
unless it be the abundance of fresh water in the latter case and perhaps the poor 
drainage of the former, due to humus packed between the pebbles. 
Samolus has been seen at but one point in the upper littoral belt (200 north 
- by 1,050 east), where it grows between the 7.5 and 8.25 foot levels associated 
with Juncus Gerardi and Salicornia, and near its upper limit bordered by 
Teucrium canadense and Psedera quinquefolia. 
Scirpus nanus is a diminutive species that occurs in the upper littoral belt 
somewhat more abundantly than either of the last two species. It usually forms 
dense turfs, sometimes a meter or more square (122 south by 1,089 east), and 
grows on fine-grained peaty soils that are often bare, or nearly bare, of other 
vegetation, except alew such as Rhizoclonium and Vaucheria (plates xx1 and 
xx11). The seed plants most often found with this Scirpus, when any are 
present, are Salicornia europea, Distichlis, Atriplex patula, and occasionally 
Spartina glabra. Scirpus nanus is confined to a half dozen locations on the 
Marsh (e. g., 500 south by 700 east, 25 north by 1,100 east), one area on the east 
shore near the mill (400 to 480 north), and two areas on the west shore (660 
north at 7.5 feet and 850 north at 7 feet). The soil on which this plant grows 
is always pretty completely saturated with salt water, the fine texture of the soil 
enabling it to hold the water well from one high tide to the next. At 6 south by 
1,050 east, at 7.33 feet, this plant was growing well at the margin of a tide-pool, 
the surface of which, for the purpose of killing mosquito larvee, had been kept 
covered during the summer with crude petroleum. The Scirpus we are discuss- 
ing occurs chiefly in sunny spots, and between 6.5 and 7.5 feet, although it has 
been found as low as 6.25 and as high as 8 feet. 
