The Flora of Namonuito and the Hall Islands 
Benjamin C. Stone^ 
Approximately 160 miles northwest of Truk, 
in the Caroline Islands, lies Namonuito Atoll, 
straddling the 150th W. meridian. Lying suc- 
cessively to the east are Fayu, Nomwin, and 
Murilo atolls, comprising the Hall Islands. 
Together these strips of land amount to no 
more than a few square miles, but they are 
scattered over three and a half degrees of 
latitude, approximately eight and a half de- 
grees north of the equator. Namonuito con- 
sists of some seven major islets and several 
minor ones. Beginning at the southwest, 
these are: Ulul (or Olol), Namonuito, Mage- 
rerik (Magurchuk), Magur (Magerlap) , Ono, 
Onari, Weltot, and Pisarach. Sixty miles east 
is Fayu, an uninhabited island which is visited 
from time to time because of the abundant 
hsh and turtles. Thirty miles farther east is 
Nomwin Atoll, with its two inhabited islets, 
Nomwin and Fananu, and other smaller islets. 
East again of Nomwin is Murilo Atoll, of 
which Ruo and Murilo islets are inhabited. 
These major islets are strips of coralline land, 
rising to a height of 5 feet or rarely somewhat 
more, usually with a central depression. 
The general aspect of any one of these islets 
is much like any other; a reef, a strip of beach, 
and the coconut-palm skyline. Granted the 
sparse flora and the omnipresent coralline 
soils, they have rather considerable variation. 
The three atolls here considered differed not 
only among themselves but also as a group 
differ from other atoll groups, such as the 
Marshall and the Gilbert islands. There are 
important differences in the floristic make-up 
and, consequently, in the ecological balance 
of the species present. Yet in a broader sense 
there is a remarkable sameness about the 
forested atolls of the Pacific, and many of the 
1 Department of Botany, University of Hawaii. 
Manuscript received November 4, 1957. 
species herein recorded might reasonably be 
expected to occur on any of the Micronesian, 
or even Polynesian, atolls. This applies not 
only to indigenous species but to weeds and 
crop plants. 
Namonuito, Nomwin, and Murilo were 
visited by the author in June and July of 1957 
while collecting Fandamis specimens for Dr. 
Harold St. John’s National Science Founda- 
tion Project, which was begun at the Uni- 
versity of Hawaii in 1955. 
These atolls have a fairly constant tempera- 
ture usually ranging from 75° to 90° F.; 
breezes are nearly always present; rainfall, 
though scattered, supports a thriving forest 
flora in the less disturbed islets. Extreme dry- 
ness, such as may be encountered in the 
northern Marshall Islands, is not a feature of 
this area, though droughts may occur. The 
heat is most extreme on sandy spits with little 
or no plant cover, situations which are un- 
favorable to many species but which may be 
colonized by Ipomoea pes-caprae, Scaevola fru- 
tescens, Fimbristylis atollensis, and Lepturus repens. 
Several of the islets have swampy central 
depressions, and on Pisarach there is a true 
swamp at the southern end with characteristic 
swamp species including Acrostichum aureum^ 
Cyclosorus goggilodus^ and Bruguiera conjugata. 
On certain islets, ordinarily uninhabited, a 
rather well-developed Pisonia forest flourishes, 
usually in company or codominant with Eu- 
genia. The trees are large-boled and may rise 
to 70 or 80 feet. The undisturbed forests have 
little or no ground cover beneath the trees. 
These presumably native forests are now 
much cut-over and cleared, or burned for 
clearings. In these clearings a wide array of 
species, both native and weedy, occurs; near 
villages various crop plants are cultivated, 
namely, coconut palms, taros, bananas, pa- 
payas, and tobacco. Other large trees fre- 
88 
