- S. G. Heritiera littoralis.
- G. Smythea pacifica.
- G. Dalbergia monosperma.
- S. G. Derris uliginosa.
- S. G. Pongamia glabra.
- G. Desmodium umbellatum.
- G. Gyrocarpus jacquini.
Section IV. The floating power is derived from empty seed-cavities, where owing to abortion of the ovule or some similar cause the seed is not developed.
- S. G. Morinda citrifolia.
- G. Premna tahitensis.
Note.—Professor Schimper, in the case of Morinda citrifolia, holds the view that we have here a special adaptation to dispersal by currents.
Second Group.—Here the floating power is due mainly or entirely to buoyant kernels. In the case of seeds the tests are non-buoyant; but with “stones” the floating capacity may be aided by a layer of air-bearing tissue inside the shell.
Section I. Non-Leguminous.
- S. G. Ximenia americana (drupe).
- S. G. Calophyllum inophyllum (drupe).
Note.—Professor Schimper would place these two plants in the second section of the third group on account of the layer of air-bearing tissue inside the shell of the “stone”; but they are assigned to this section, since the floating power is mainly due to the buoyant kernel.
Arenaria (Honckeneya) peploides, a British beach plant, belongs here.
Section II. Leguminous seeds.