358 BOTANICAL GAZETTE [NOVEMBER 
mit the occasional immersion which the plant undergoes at 
the higher tides, but is insufficient to permit immersion so pro- 
longed as that of Spartina. It is this feature that determines 
the difference in position of the two plants; the Salicornia can 
apparently stand as much salt as. the Spartina, but it cannot 
stand long immersion, and hence it is confined to a higher 
position on the river banks.39 
The physiological correlations of the species appear not to 
have been studied. I have, however, found that the root-hairs 
of the seedlings can withstand without plasmolysis a solution of 90 
per cent. pure sea-water, which fact helps to explain its halophytic 
capacity. It is wind-pollinated, and apparently, wind-dissemi- 
nated, though the seeds are provided with hooked hairs. It 
appears to me to be polyembryonic.. 
SUAEDA MARITIMA Dumort. Dondia maritima (L.) Druce.— 
Appears to have no local name. Occurs most commonly inter- 
mixed with the Salicornia, though extending into less salt places, 
and forming the second member of the Salicornetum (fig. 72). 
Vegetation-form in a general way approaching that of Sali- 
cornia, but a leaf- instead of a stem-succulent and much less 
markedly xerophytic. Its root-hairs can endure 60-70 per cent. 
salt water without plasmolysis. Fibrous-rooted annual with semi- 
succulent stem, usually prostrate but sometimes in saltless places 
erect, with efficient epidermis having a thick cuticle and much 
collenchyma, bearing numerous somewhat succulent bluish green 
slender leaves which can be up to 2™ (5™) long. Leaves 
with large rounded epidermal cells, and stomata about equal on 
all faces, dense palisaded chlorenchyma and some water-storing 
cells. The leaves afford some protection against transpiration 
to one another and the stem by overlapping. Little trace 
of air-storing system, and hence not enduring immersion well, 
which explains why it grows rather higher on the beaches than 
the Salicornia. It is wind-pollinated and apparently wind- 
disseminated. 
SPERGULARIA BOREALIS Robinson. Tissa Canadensis ( Pers.) 
39 Diehl’s conclusions that this plant has a power of removing salt chemically from 
its tissues are not substantiated. ; 
