212 CALIFORNIA ACADEMY OF SCIENCES LProc. 4th Ser. 



moisture present is greater than is ordinarily the case. Those 

 species which are decidedly hydrophytic, or show tendencies 

 in this direction, are some of the species of Adiantum, Asplen- 

 ium cristatum, and the species of Hymenophyllum and Tricho- 

 manes. Epiphytic species include Asplenium praemorsum and 

 sulcatum, Nephrolepis pectinata, Polypodium angustifolium, 

 aureum, lanceolatum, lepidopteris, polypodioides, and thyssan- 

 olepis. Over one half of the species of Polypodium found on 

 the islands are epiphytic in habit, all but one, in fact, being 

 habitually so. Fern brakes of considerable size are formed 

 by Nephrolepis hiserrata, and Pteris aquilina var. esculenta, 

 while Polypodium squamatum often forms low brakes one to 

 two feet high in moist shady places in the transition region. 

 Hemitelia midtiHora is the only tree fern, and is confined to 

 the upper parts of three of the higher islands. Ferns have 

 now been found on all of the important islands of the group 

 except Barrington, Culpepper, Seymour, and Tower, the con- 

 ditions on these islands being too dry to support even the more 

 xerophytic species. The water ferns are of relatively little 

 importance in the archipelago, being represented by a species 

 each of Asolla and Salvinia. 



The Lycopodiaceae are represented by five species of Lyco- 

 podium, all of which occur in the moist and grassy regions of 

 the islands. Two of the species are epiphytic and the remain- 

 ing three terrestrial. The Equisetaceae are represented by a 

 single species, Equisetum hogotense, which occurs in a very 

 small area on the top of one of the mountains on Albemarle 

 Island. 



SPERMATOPHYTA 



Monocotyledoneae 



The Cramineae are the fourth largest family, in number of 

 species, found on the islands. By far the largest number of 

 the species are confined to the dry and transition regions, the 

 moist region being too shady, in most places, to support an 

 abundant growth of grass. The only grass of any importance 

 which occurs above the transition region is Paspalum conju- 

 gatum, which often covers extensive areas in the grassy region 

 and forms an important forage grass for the cattle and other 

 domesticated animals on the islands. Grasses which occur 



