FLORA OP THE GALAPAGOS ISLANDS. 251 



about 50 km. away. Tower rises only 65 m. above sea level. It 

 has been visited by Dr. Baur, 2 September, 1891, and by Messrs. Snod- 

 grass and Heller, June, 1899, who have together secured only 19 dif- 

 ferent kinds of plants upon it. Of these, 5 are Euphorbiaceae, and 3, 

 Convolvulaceae. There are no ferns, and what is more remarkable, no 

 Amarantaceae , Leguminosae, Rubiaceae, or Gompositne^ all of which 

 are families exceptionally well represented u[)on most of the other 

 islands. The only plant peculiar to the island is Euphorbia viminea, 

 forma castellana, merely a well marked leaf-form of this polymorphous 

 species. It is worthy of note, however, that in the size, shape, and 

 thickness of its leaves, this form on Tower represents the opposite 

 extreme from the variety of the same species found on the adjacent 

 island of Abingdon. Eleven of the 19 plants observed on Tower are 

 confined to the Galapagos Islands. 



Wenman Island. 



Wenraan is a rocky islet, which, like Culpepper (43 km. distant), lies 

 considerably to the northward of the other islands. For botanical pur- 

 poses it has been visited only by Messrs. Snodgrass and Ileller, who 

 remained there from the 12th to the 18th of December, 1898. Mr. 

 Heller's field notes, so far as they relate to plants, are as follows : 

 "The main part of the island is largely inaccessible, but, like Culpepper, 

 covered with a fair growth of vegetation. Through a glass the larger 

 plants appeared to be Croton, Optintia, and on the north side a cluster 

 of leafless trees, each about a foot in diameter and twenty to thirty feet 

 high, with a smooth brownish bark. In an inaccessible cave a Polypo- 

 dium was seen. Our collecting was confined chiefly to a low detached 

 islet north of the main island. Its vegetation consisted of a low Opuntia 

 \Helleri'], which grew in thick beds near the edges of the cliffs. Many 

 of these were covered with greenish-yellow flowers and others with dry 

 and prickly fruit. The central [)art of the islet was covered by a heavy 

 growth of Croton [^Scoideri, var. brevifoUus] bushes. These were largely 

 leafless, although a few were in flower. In habit they resembled sap- 

 lino-s, with straight trunks ten feet high and an inch or two thick. An 

 Ipomoea \_Kinberfji'\ was common, twining among the Crvtun bushes. 

 This had large white flowers. A Telanthera [Helleri, var. obtasior'] 

 was also common about the cliffs and near the Opuntia thickets. Dried 

 stalks of a Cyperus were noted. On a talus slope of the main island the 

 following species were collected : Scalesia [Snodgrass ii], bushes two or 



