238 PROCEEDINGS OF THE AMERICAN ACADEMY. 



They are neither so numerous nor conspicuous as iu the tropical parts of 

 continental America, and it may be noticed that the climbers of the 

 Galapagos Islands are herbaceous, the true woody liana, so common in 

 tropical jungles, being almost unknown upon these islands. 



Epiphytes occur only at the higher altitudes and are neither abundant 

 nor showy. Their ecological class is chiefly represented by one Tilland- 

 sia, one Epidendrum, and several Peperomiae. Of phanerogamic para- 

 sites there are four species of Phoradertdron and two of Cuscuta. 



The phanerogams of the Galapagos Islands have prevailingly small 

 and inconspicuous flowers, although exceptions are not infrequent. It is 

 also worthy of remark that the flowers are in most cases regular and of 

 a rather simple structure. Zygomorphic flowers are not numerous, and 

 even in such genera as Epidendrum, Salvia, etc., where zygomorphy is 

 universal, the Galapageian species show this trait only moderately devel- 

 oped. Similarly, flowers with other highly developed mechanisms for 

 securing cross-pollination seem to be very rare in the islands. Fruits 

 with hook apparatus or spines to aid their distribution by mammals are 

 found in Cenchrus, Tribulus, Acanthospermum, Bidens, and Lecocarpus ; 

 but by the decided reduction in the spines of most of the species of 

 Cenchrus, and in a variety of Tribulus cistoides, as well as in Acantho- 

 spermum microcarpum, it is easy to remark a tendency toward abortion 

 in this apparatus, — a fact readily explained by the paucity of indigenous 

 mammals. Of course the settlement of the islands has brought intro- 

 duced mammals in considerable quantity, but it is too recent to have had 

 a perceptible influence in this matter. 



Affinities of the Flora. 



The flora of the Galapagos Islands is almost wholly American in char- 

 acter. It contains, it is true, a very few plants which are not found in 

 America. Thus a slight relationship to the flora of the Hawaiian 

 Islands might be inferred from the genus Lipochaeta, of which one 

 species is Galapageian and the others Hawaiian. There is also a report 

 of a Vigna common to the Hawaiian Islands, the Galapagos, and Chili, 

 — a matter which I have been unable to verify. Ipomoea campanulata 

 of the East Indies and Malayan Archipelago occurs on the Galapagos 

 Islands, but not to my knowledge upon the continent of America. This 

 is probably a chance introduction. Several species of the Old World, 

 such as Vitis vinifera, mentioned by Caruel (1), 623, Brassica campes- 

 tris, B. Sinapistrum, and Raphanus sativus, are of course relics of 

 cultivation or introduced weeds. Eleocharis Jistulosa, ascribed by Caruel 



