2 THE PI^ANT WORIvD 



weather coast. Trees with thick foliage would probably be uprooted, 

 but the wind sweeps through their leafless branches with little resistance, 

 though the trees here have a battered appearance and are twisted and 

 gnarled from the effects of the many storms and hurricanes which have 

 visited the island. They scarcely bore any resemblance in their general 

 contour to the straight, slender saplings from which the Samoans make 

 their spears or the perfect trees which form avenues at Waikiki, near 

 Honolulu, yet they are the same species. In Eastern Polynesia they are 

 called toa, which also signifies "warrior"; here they are called gago. 

 It is interesting to note that though they grow well with their roots im- 

 mersed in sea-water they are not necessarily dwellers of the beach. On 

 the upland regions of this island, called sab anas, they occur sparsely 

 scattered among the sword-grass {.Miscanthus florididus) . These sabanas, 

 or savannas, are characterized by lack of drainage, and it may be that 

 the conditions necessary for the growth of the iron wood are moisture 

 just below the surface, plenty of sunlight, and a free sweep of the wind. 

 Some of the finest specimens on the island grow on the south coast of the 

 island, between Merizo and Inarahan. (See figure.) The branches, which 

 are jointed like horse-tails {.Equiseta) , look from a distance like pine- 

 needles, and the many-celled woody fruit are like certain pine-cones, but 

 are of a spherical shape. Many of these were strewn on the beach and some 

 of them still contained seeds. Throwing a number of them into the sea 

 they floated like corks and were soon brought back by the waves, and 

 when I tossed a handful of the winged seeds into the air they were 

 carried inland by the fresh breeze which was blowing. This is an inter- 

 esting demonstration of the forces which play a part in the distribution 

 of plants. The buoyant fruits may be carried from island to island by 

 ocean currents and gain foot-hold upon the sandy beaches ; and the 

 winds will carry inland the seeds, which will establish themselves where 

 conditions are favorable. The delicate membranous wing of the seed is 

 strengthened bj- a slender rigid rib, evidently the persistent style. 



Back of the outer line of vegetation and sometimes mingling with it 

 grew typical trees of what Schimper has called the " Barringtonia Form- 

 ation": Barringtonia speciosa, Barringtojiia raceniosa, Terminalia catappa, 

 Hibisctis tiliacetis, Thespesia populnea, Calophylliivi ijiophylhini, Her7iandia 

 peltata, Morinda citrtfolia, and an Apocynaceous tree resembling Cerbera 

 (probably Ochrosia viarian7iensis) . Nearly all these trees have fruit or 

 seeds specially adapted for floating.* In the Barringtonias and the Apocy- 

 naceae there are fibrous husks ; in Morinda citrtfolia there is a distinct 

 air-chamber, and in some of the sea-beans (^Muaina gigantea and Entada 

 scandens^ there is a large air-space between the kernels (cotyledons) and 



♦See Guppy, H. B.— " The dispersal of plants as illustrated by the flora of the Keeling or Cocos 

 Islands," Tratisactions of the Victoria Institute, 1890. Also Schimper—" Die Indo-malayische Strand- 

 flora, p. 165." Taf. vii. Jena, 1891. 



