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II• V ascular plants of Tern Island, French Frigate Shoal 
Through the courtesy of the United States Coast Guard and Dr. Harold ‘ 
F. Coolidge, the author was able to visit Tern Island on September 2, 1961 . 
Since only half an hour ashore was available, during which time a circuit 
of the island was made, the observations reported here should be consid¬ 
ered as "preliminary”. I wish to express my appreciation to H. Ivan 
Rainwater who supplied me with a list of his collections from French 
Frigate Shoal, and to Dr. V. J. Krajina and Miss Marie Neal who assisted 
in the identification of the material designated here as A triplex muel - 
leri. 
French Frigate Shoal, about 480 miles northwest of Honolulu, is a 
crescent-shaped atoll on which are a number of sand islets. A few miles 
to the southwest are two rock islets, remnants of the original volcanic 
island.- Tern Island, one of the sand islets (23° 5^ f N. Lat., l 66 ° 19* 
W. Long.), is now the site of an airstrip and a United States Coast Guard 
loran station. 
The botanical history of Tern Island is brief. The Tanager Expedi¬ 
tion in I 923 (Christophersen and Caum, 1931) found five species of 
vascular plants growing there: Lepturus repens, Chenopodium sandwicheum, 
(now C. oahuense ), Boerhavia diffusa , Portulaca lutea and Tribulus cisto - 
ides . During World War II the. airstrip was constructed and some time 
later the loran station was built. H. Ivan Rainwater made plant collec¬ 
tions on Tern and other islands in October, 1953* The second published 
observations were by Svihla (1957), who visited the island in 1956 , and 
reported that the flora consisted of ‘’various grasses”-, Ipomoea pes - 
caprae , Scaevola (probably S. sericea although no species was cited), 
and cultivated plants of Cocos nucifera and Casuarina sp. 
Most of the surface of Tern Island is now occupied by the crushed 
coral airstrip which is 3100 feet long and drops off sharply into the 
water at the east and west ends. Along the south, edge of the airstrip 
is an unpaved area 10 to 50 meters wide on which the living quarters are 
located. There is an extensive sandy beach along the south shore. On 
the north edge of the airstrip the unpaved area is up to 20 meters wide 
and there are only a few small sandy beach areas. The island is about 
two meters high. It is likely that little, if any, of, the' surface of the 
island was left untouched when the airstrip was constructed (see note p. 10 \ 
The unpaved area south of the airstrip is rather densely covered 
with shrubs of Messerschmidia argentea and Pluchea odor at a , and an herb¬ 
aceous cover in which the predominant species are Ipomoea pes~caprae, 
Boerhavia diffusa,- Cenchrus echinatus, Setaria verticillata7~Sonchus 
11 ,l ’ 1 1 *" IILI 1 " 1 ll """ 111 11 1 111 1(1,11 1 , nn mi ww w ji .an ■ i ' mi wm m « ■ —nf i w w Mij mu»mm M W 
oleraceus , and Conyza bonariensis . Of less frequent occurrence here are 
Eleusine i ndica , Lepturus repen s, Portulaca lutea and P. oleracea. One 
large clump of Scaevola sericea is present southwest of the living 
quarters. Spergularia marina is abundant on the margins of the airstrip. 
The unpaved area on the north side of the island is less densely vegetated 
than that on the south. Pluchea odorata is present, but the shrubs are 
widely scattered. Very few plants of Messerschmidia argentea are present. 
