100 
PACIFIC SCIENCE, Vol. XXI, January 1967 
Fig. 2. Prof. W. H. Goodenough, during his 
lengthy visit on Romonum. 
was helpful in many ways. Prof. W. H. Goode- 
nough and Mrs. Goodenough provided house 
and sustenance on Romonum, and Oliver 
Goodenough acted as guide. Finally, I must 
thank the College of Guam and especially Dr. 
A. C. Yamashita for the opportunity and sup- 
port provided for the work undertaken on this 
trip ; and thanks are also due to the many other 
friends who were of assistance. 
THE FLORA OF ROMONUM ISLAND 
The following key and species list is un- 
doubtedly not complete, but it includes the 
most common species of vascular plants on 
Romonum. There are probably additional spe- 
cies on the northeastern part of the island, 
which I did not cover thoroughly ; and no doubt 
some weeds and cultivated plants were missed, 
or will be introduced in the future; still, the 
species cited here represent, I believe, the 
bulk of the island’s vegetation. A key to species 
is provided, but of course it can only account 
for the species listed, and additional discoveries 
will have to be added. A number of plants are 
absent or represented very sparsely; Messer- 
schmidia , for example, common on atolls and 
limestone areas of other islands, was not found ; 
Pemphis was seen only once, and as an isolated 
individual; Ipomoea pes-caprae was not found, 
but may well occur on the north beach (its com- 
mon associates, such as Canavalia maritime i, 
W edelia bi flora, and Scaevola were found) ; 
Polys cias grandifolia, Soulamea amara, Suriana, 
Pisonia grandis, and other representative atoll 
species, found elsewhere in Truk, did not ap- 
pear. In this respect Romonum resembles 
Yanagi Islet, only a few miles away in Truk 
Lagoon, the vegetation of which was described 
a few years ago (Hill and Stone, 1961), and 
which interestingly is also deficient in species 
typically associated with coral atolls. 
KEY TO SPECIES 
Only the vascular plants are accounted for here ; for bryophytes the reader is referred to Miller, 
Whittier, and Bonner (1963) ; for marine algae to Okamura (1915) and Taylor (1950) ; for 
other groups there is no comprehensive treatment for Truk, but papers on lichens and fungi have 
been written by Imazeki (1941), Kobayasi (1939), Jatta (1903), and Sydow and Sydow (1921). 
I. Flowerless plants bearing spores in sporangia, these usually borne on the backs or edges of fronds (Ferns) 
1. Fronds simple, to several feet long, forming a large nest or rosette; epiphytes; sori (groups of sporangia) oblique, 
linear Asplenium nidus 
1. Fronds lobed or divided 
2. Sporangia covering the entire lower surface of the leaflets; fronds to several feet long, leathery, somewhat dimor- 
phic; 1-pinnate; swamp ferns Acrostichum aureum 
2. Sporangia in groups (sori) 
3. Fronds deeply parted, the lobes entire; sori sunken in pits, these evident on the upper surface as bumps; ter- 
restrial or epiphytic ferns with creeping rhizomes Phymatodes scolopendria 
3. Fronds pinnate or bi- or tripinnate 
4. Fronds 1-pinnate . 
5. Sori kidney-shaped; lobes of pinnae crenate Nepbrolepis 
