218 CALIFORNIA ACADEMY OF SCIENCES  [Proc. 47H Srr. 
The Compositae stand second in number of species of all of 
the families of vascular plants occurring on the islands. Many 
of the common herbaceous annuals of the dry and transition 
regions, as well as some of the most important bushes, belong 
to this family. The Compositae are however most strikingly 
represented in the moist regions, where extensive forests of 
Scalesia, made up for the most part of S. pedunculata, occur. 
This genus is also well represented in both the dry and transi- 
tion regions by shrubby species, which sometimes occur in 
large numbers over considerable areas. Other noteworthy 
members of the family are the species of Erigeron and Lipo- 
chaeta, both of which are important where they occur. 
The remaining families of vascular plants represented on the 
islands contain but few species and for the most part are of 
relatively little importance. 
The plants which occur under halophytic or semihalophytic 
conditions are included in the following genera: Ammophila, 
Atriplex, Avicennia, Batis, Cacabus, Conocarpus, Coldenia, 
Cryptocarpus, Eleocharis, Heliotropium, Hibiscus, Hippomane, 
Ipomoea, Laguncularia, Lycium, Maytenus, Najas, Rhizo- 
phora, Ruppia, Salicornia, Scaevola, Sesuvium, and Sporo- 
bolus. 
Hydrophytes are comprised in Azolla, Callitriche, Eleo- 
charis, Lemna, Myriophyllum, Jussiaea, and Salvinia, all of 
which are of little importance in the composition of the flora, 
as they mostly occur periodically when there is a supply of 
fresh water in the ponds and brooks. 
Outside of a few species of ferns, the only vascular epiphytes 
are three species of orchids, two or three species of Peperomia, 
and a Tillandsia, the last of which is the most common and 
largest of the epiphytic plants. All of the above are practically 
confined to the transition and moist regions, occurring above 
the last in only a few instances. Phanerogamic parasites are 
represented by four species of Phorodendron, only one of which 
is sufficiently abundant to be of importance in this respect, and 
two species of Cuscuta. The first of these parasites is found in 
all of the regions, but is most abundant in the moist, while the 
second is confined to the dry and transition zones and so far 
as was observed only appears for a short time during the spring 
months. 
