236 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. 



SUMMARY 



This reconnaissance of a full series of isolated and grouped sub- 

 tropic sand keys, appears to prove that such species as are able to 

 avail themselves of avevectent and aquavectent transportation, and 

 can withstand, or actually need, a surcharged saline soil and atmos- 

 phere avail themselves, with more or less heterogeneity of association, 

 of those sands upon which their seeds are cast; there to spread in just 

 so far as their demands for nourishment and needful space will permit. 

 Ventevectant transportation appears to play no part whatever in the 

 vegetal colonization of such isolated portions of land. 



DISTRIBUTIONAL NOTES 



Agave decipiens : 



This species undoubtedly has been planted qn Marquesas "E" by 

 the charcoal burners who once camped thereon. There are abou* a 

 dozen of the plants together not far from the location occupied 

 formerly by their hut.* It was probably planted there that it might 

 serve in lieu of soap when stores of that detergent failed. 

 Amaranthus viridis: 



See note under Argemone leiocarpa. 

 Argemone leiocarpa : 



This species is one of the forms of the common Antillean weed 

 A. mexicana, appearing, like its frequent companions Bidens leucantha, 

 Sonchus oleraceus, and Amaranthus viridis, frequently about the hab- 

 itations of man. Their introduction on Garden Key is doubtless due 

 to ballast shifting, as are also Capraria biflora, Euphorbia adenoptera, 

 Heliotropium curassavicum and Sesbania sericea. 

 Avicennia nitida: 



Occurs only in association with the mangrove and even then only 

 on the receding, and drying borders. (On the south side of New 

 Providence, in the Bahamas, it is, however, found in the open but 

 shallow sea fully a hundred yards or more from the shore.) 



* See under Rhitophora mangle. 



