702 Part IV. Chapter 7. 
water ponds, especially at Walsingham, are fed by underground channels so 
that the water in them rises and falls with the tide. Here grow several 
interesting marine algae, such as: Valonia utricularis, Caulerpa plumaris, C. 
racemosa and Colpomenia sinuosa. Thalassia testudinum grows in all shallow 
bays. 
Mangrove Formation. The mangrove swamps occur at the heads of bays 
especially along the south shore of the Bermudas and in the salt water ponds 
which are here and there found distributed over the islands. The vegetation 
consists either of a pure growth of Rhizophora mangle with its prop roots 
extending in all directions, or a pure growth of Avicennia nitida (in. flower in 
June) with its numerous asparagus-like root knees projecting through the sticky 
mud at low tide. In some places, as in Castle Harbor, both Avicennia and 
Rhisophora are in association and frequently one finds arising from the mud 
the green brush-like tops of Penicillus capitatus. Little else grows beneath 
the dense shade formed by the overarching crowns of these trees. Frequently 
a morass is formed by either Rhisophora, or ae taking possession of 
a shallow inland pond which thus becomes a swa 
Salt Marsh- and Brackish Marsh Formation. This is found at the head 
of bays and elsewhere where the soil is influenced by the tides. In such a 
marsh along Harrington Sound the writer noted Saliwornia ambigua, Helio- 
tropium curassavicum, Sesuvium portulacastrum, a number of sedges and a 
single tree of Avscennia. The rare Statice Lefroyi, identic with Siatice Limo- 
nium var. carolinianum is a salt marsh plant. The Brackish Marsh For- 
mation exists in depressions some distance inland, where marshes occur, such 
as Smiths Parish Marsh, Devonshire Marsh, Pembroke Marsh, all of which 
were investigated by me. Paget Marsh was visited by N. L. BRITTON and 
STEWARDSON BROWN?) | 
Smiths Parish Marsh is devoid of trees. Here in the soil rendered brackish by under- 
ground channels grow Typha angustifolia in pure association, Baccharis glomeruliflora, Myrica 
cerifera in thickets, Dichromena colorata, Seirpus lacustris, while Osmunda einnamomea is frequent. 
Acrostichum aureum forms pure associations at the edge of this marsh. — Devonshire Marsh 
is a er area with a few pools of water in the depressions. It gives evidence that it was once 
a pond. Juniperus Bermudiana, Sabal en and Baccharis glomeruliflora have encroached 
on this marsh so as to shade it. e ground in the wettest places according to COULTER?) 
are Hydrocotyle asiatica, Herpestis ee Mentha viridis, M. piperita and a white bracted sedge, 
Dichromena colorata. On the drier ground, Osmunda regalis and O. cinnamomea become abun- 
dant, while in the still drier peaty soil, according to my observations, Pteris aquilina var. caudata 
is growing vigorously. Typha angustifolia is in some places in pure association. 
aureum also forms pure associations here and there in this marsh. 
two species of Sphagnum, Proserpinaca palustris and Lemna minor). 
Acrostichum 
The pools are occupied by 
1) BROWN, STEWARDSON, Notes on the Flora of the Bermudas. Proc. Acad. Nat. Sci. 1909: 
486—494. 
2) CoULTER, S. M.: An ecological Cömpasison, of some typical Swamp Areas, ı5th Report 
Missouri Bot, Garden 1904: 62. 
According to N, L, BRrrron and STEWARDSON BROWN who visited the islands August 31 
—September 20, 1905, it is Lemna cyclotosa, 
