Flora of Namonuito “■ STONE 
fragments. In depth this soil may reach six 
inches, a fairly good soil for an atoll. 
Ono Islet consists chiefly of coconut groves 
and the usual strand species. Fisonia is absent, 
and so, apparently, is Glochidion. 
Pisarach Islet has both the largest village 
(over 100 people) and the most varied vegeta- 
tion. Although no Pisonia forest was seen, the 
abundant large breadfruit trees, mixed with 
Eugenia, Ficus, Ochrosia, Crataeva, and coconut 
palms make up a tall shady forest with a sparse 
under-story over much of the islet. The south- 
ern end of the islet is a natural swamp. Irriga- 
tion channels crisscross part of it, and 
Cyrtosperma, Colocasia, and bananas are planted. 
Most of the swamp is, however, a tangled 
mass of small trees, clambering vines, and 
clumps of marsh fern, all rooted in mud or 
standing pools. The seaward margin of the 
area is sandy, and behind this is a line of coral 
fragments, which quickly merges into the 
inner area of black, sandy, then mucky soil. 
Coconuts grow here to some extent. Trees of 
the swamp are Hibiscus tiliaceus, Barringtonia, 
Premna, Pandanus, Eugenia, and Bruguiera. In 
the cultivated portions, besides the taros, 
there are Ekocharis, Cyclosorus, Cyperus, Jussiaea, 
Vigna, Clerodendrum, and Digitaria, Forming 
thickets or clumps, often over large areas, is 
Acrostichum, and Vigna and Clerodendrum 
scramble over the other species. In the muddy 
but not water-covered areas coconut palms, 
breadfruits, Ficus, Eugenia, and Crataeva are 
found, with Nephrolepis, Microsorium, Piper, 
Thuarea, and Digitaria as ground cover. 
Nomwin Atoll is notable for the abundance 
of Glochidion, which is the dominant shrub in 
the forest under-story. It accounts for at least 
fifty per cent of the ground cover on Nomwin 
Islet. The eastern extremity of Nomwin Islet, 
however, is a wind-swept savannah dominated 
by dwarf stunted pandanus and the rosette- 
forming Eimhristylis atolknsis. The usual strand 
shrubs occur only as severely stunted indi- 
viduals. The weedy Eragrostis amabilis is 
abundant here also, complete flowering speci- 
91 
mens of which may measure only one inch in 
length. The soil is a rough mass of coral frag- 
ments slightly intermixed with fine sand, and 
no organic layer except fallen pandanus leaves. 
Murilo Atoll is very similar to Nomwin, 
being dryish, with no swamps, the soil light, 
thin, and sandy. The islet profile shows a con- 
siderable central dip, the seaward rim being 
built up of coral boulders forming a "cliff” 
some eight feet in height, sloping steeply to a 
narrow sandy beach fronted by a reef of coral 
pavement. The forest is chiefly coconut palms, 
breadfruits, Eugenia, Pandanus, Crataeva, and 
the strand trees. The forest under-story is 
mainly Wedelia, both species of Piper, Calli- 
carpa, Vigna, Morinda, and Ipomoea gracilis 
Glochidion is conspicuously absent. The la- 
goon shore is dry, wind-swept, and open; it 
is notable for the presence of Suriana, Sophora, 
and Euphorbia Chamissonis, all in great abund- 
ance, as well as the usual strand species. 
As can be seen from the brief summaries 
above, the floristic composition and the eco- 
logical patterns of the various islets differ to a 
surprising extent. The abundance of Piper on 
many islets, and the abundance of Glochidion, 
on Nomwin especially, though also to a lesser 
extent on Ulul, is in marked distinction from 
atolls in the Marshall Islands, or from Mokiel, 
Pingelap, Ngatik, Nukuoro, or Kapingama- 
rangi. Curiously, the reef islets of Truk, like 
Nomwin, abound in Glochidion; but on most 
of Namonuito and Murilo it is apparently ab- 
sent. On the high islands of Truk is a large 
shrub, abundant on low hillsides, which is 
probably Glochidion ramiflorum Forst. Whether 
the atoll Glochidion is conspecific is a matter 
of doubt, and until a monographic treatment 
appears, there seems little value in appending 
one of the dubious names to these plants. As 
Croizat (1943) shows, the delimitation of spe- 
cies in the genus is still highly problematic. 
Another plant quite common on both the 
high and low islands of Truk, but which 
apparently does not occur at all in Namonuito 
or the Hall Islands, is Polyscias grandifolia. 
