FLORA OF THE GALAPAGOS ISLANDS. 241 
tween the flora of the Galapagos group and that of Cocos Island. The 
latter is situated about three-sevenths of the way from the coast of Costa 
Rica to the Galapagos Archipelago. Until very recently the flora of 
Cocos Island has been scarcely known at all. Largely through the 
efforts of Professor H. Pittier and Messrs. Snodgrass & Heller, about 
eighty plants have now been secured on the island, and of these only 
the following eighteen are common to the flora of the Galapagos group: 
Plagiochila Anderssonii Paspalum conjugatum 
Acrostichum aureum Paspalum distichum 
Asplenium rhizophyllum Caesalpinia Bonducella 
Nephrolepis acuta Euphorbia pilulifera 
Polypodium aureum Ricinus communis 
Polypodium lanceolatum Hibiscus tileaceus 
Polypodium Phyllitidis Ipomoea biloba 
Eleusine indica Ipomoea Bona-nox. 
Panicum sanguinale 
It will be noticed that with the exception of the hepatic (Plagiochila 
Anderssonii) all of these species are weeds or plants of wide tropical 
distribution, 
CoMPOSITION OF THE FLORA. 
As with most insular floras, the vegetation of the Galapagos Islands is 
striking rather by the absence of certain great, groups than by the 
number and diversity of the genera and families represented. For in- 
stance, in the pteridophytes there is a total lack of arborescent forms on 
the one hand and of the filmy ferns ( Zrichomanes, Hymenophyllum, ete.) 
on the other. There are no gymnosperms; and among the monocotyle- 
dons there are no palms, aroids, rushes, or Liliaceae. Indeed, if we 
except the grasses and sedges (both well represented), the monocotyledons 
are shown only by some half-dozen scattered species. Among the di- 
cotyledons the families best represented are the Amarantaceae, Nyetagi- 
naceae, Aizoaceae, Leguminosae (about 10 per cent of the phanerogamic 
vegetation), Euphorbiaceae (about 12 per cent), Malvaceae, Cactaceae, 
Convolvulaceae, Boraginaceae, Verbenaceae, Labiatae, Solanaceae, 
Rubiaceae, and Compositae (about 13.5 per cent). Several great dicoty- 
ledonous families, widely distributed and abundant in the tropics of 
continental America, such as the Sapindaceae, Myrtaceae, Melastomaceae, 
Lythraceae, and Onagraceae, are scarcely or not at all represented in the 
VOL. xxxvi11.—16 
