Scævola sericea (Forst.), a hairy variety of this littoral plant, will probably prove in some localities to be the inland form of the species. Dr. Reinecke, who mentions only this variety for Samoa, says that it is found in very moist ground in river-ravines, and no other station is referred to. It would seem that both the glabrous and hairy forms occur in Hawaii. Dr. Seemann speaks of the hairy variety as littoral in Fiji.
NOTE 56 (page [149])
On the Capacity for Dispersal by Currents of Sophora tomentosa, S. chrysophylla, and S. tetraptera
(1) Sophora tomentosa, Linn.—The moniliform pods will float for few weeks, but it is to the seeds liberated by the breaking down of the pod that the wide dispersal of this beach-plant by the currents is due. When experimenting on the freshly obtained seeds in Fiji I found that four-fifths of them floated after three months in sea-water. With seeds that had been kept for three years, half floated after twelve months and retained their sound condition. The seeds owe their floating power to the buoyant kernel.
(2) Sophora chrysophylla, Seem.—The dry pods of this Hawaiian mountain species float between one and two weeks in sea-water, but being brittle they readily break down and the seeds escape. The seeds have no buoyancy even after drying for four years.
(3) Sophora tetraptera, Ait., from the coast of Chile.—After floating from ten to fourteen days in sea-water, the dry pods become sodden and begin to break up, the seeds escaping. Since, however, the pods tend to decay and break open on the tree they would not be available for dispersal by currents. Out of a number of freshly gathered seeds all floated buoyantly after a month in sea-water, when the experiment ended; and of seeds that had been kept over a year six out of ten floated after four months in sea-water, two of them germinating afterwards in soil. Like those of S. tomentosa the seeds possess buoyant kernels to which the floating power is due. On account of the hardness of the tests the seeds to ensure rapid germination require to be filed.
NOTE 57 (page [153])
On the Species of Ochrosia
Schumann distinguishes the following species:
(a) O. parviflora, Hensl., widely spread in the Pacific islands.
(b) O. compta, Schumann, confined to Hawaii and corresponding to var. B. of O. sandwicensis as given by Hillebrand.
(c) O. borbonica, Spr., synonym O. oppositifolia, Lam., from Mauritius and Madagascar to Java and Singapore.