I 
\ 
% 
4 
11 
i 
i 
4 
i 
1 
) 
\ 
i 
< 
t 
I 
i 
t 
* 
1 
j 
l 
4 
t 
i 
J 
i 
i 
i 
J 
I 
f 
i 
L 
The Vegetation 
The vegetation of Nihoa is dominated by a low heibaceous cover comprised 
of the following: Sida fallax, Chenopodium oahuense, and Panicum torridum . 
Solanum nelsoni and Euphorbia_ c elastroides are important members of this 
vegetation type. At the time of our visit (September, 1964) the island Was 
very dry and the common grass Eragrostis variabilis did not appear as 
plentiful as previous reports on the vegetation of the island would indicate. 
This grass is probably a seasonal dominant after the rainy season. The 
Euphorbia appears to prefer exposed volcanic rock sites. No leaves were 
present on the plants observed in 1964. 
Portulaca caumii was common in the soil pockets of crevices on the 
middle and upper slopes. Portulaca lutea was dry on the lower and middle 
slopes and not obviously abundant in these areas while on the flat area 
near Miller's Peak which receives more precipitation the plants were plump 
and in flower. 
• 
Rumex glganteus vas found on the north cliff face near the top of Tanager 
Peak. Collections of lichens vere made and determinations of these are 
being made by various collaborators. The RUmex vas sterile at this time. 
Panicum torridum vas most conspicuous on the upper slopes. Sesbania 
tomentosa and Trip ulus clstoides vere found on the south side of the cliffs 
on the upper slopes - the plants flattened and very dry. Most of these 
herbs shed much of their leaves during the dry season. 
Pritchardia remota, endemic to Nihoa Island, is found in the dry 
stream beds and middle slopes of the east and vest canyons and on the east 
upper slope of East Palm Canyon and on the upper vest side of West Palm 
Canyon. A count of the Pritchardia revealed the folloving numbers: 
a) West Palm Canyon: 107 seedlings, 148 non-flovering and fruiting trees, 
127 flovering and fruiting trees; b) East Palm Canyon: 52 seedlings, 
69 non-flovering and fruiting trees, 46 flovering and fruiting trees. 
The folloving plant associations vere observed: h) on rocky upper 
slopes vith thin soils: Euphorbia - Chenopodium - Sida - Solanum ; Panicum 
- Portulaca ; Eragrostis - Sida - Chenopodium ; b~J middle and lover slopes 
vith deeper soils, some formerly held by terraces: Chenopodium - Sida - 
Eragrostis; Euphorbia on volcanic rock ridges; c) vet north face cliffs 
vith soil pockets or bare rock: lichens; Panicum - Rumex - Portulaca lutea ; / 
on middle and upper slopes in soil pockets: Portulaca caumii ; vet vest 
and south face cliffs, thin soil on bare rocks: Chenopodium - Portulaca ; 
dry lichens; stream beds and sheltered cliff bases: Pritchardia ; Chenopodium 
Sida - Solanum . At the base of West faim Valley is a sand beach vhich 
shifts prbbably on a seasonal basis. Heliotropium vas collected from this 
site in 1964. Boerhavla diffusa vas collected from this site in 1925# Ro 
evidence of Tetragonia or Schiedea vas found in 1964. Both vere Very local 
in distribution in 1923 (Christophersen and Caum, 1931)* 'Twenty-seven 
plants of Heliotropium vere counted, mainly on the slopes above the beach. 
