Aluminum in Some Hawaiian Plants^ 
J. C. Moomaw, Martha T. Nakamura, 
and G. Donald Sherman^ 
The recent interest in Hawaiian gibbsitic 
soils (Sherman, 1957; Tamura, Jackson, and 
Sherman, 1955) as a potential commercial 
source of aluminum has stimulated concurrent 
interest in the plants of these latosols. 
The major and closely related questions 
that arise concern (1) the role of plant species 
or plant communities as indicators of alumi- 
num, (2) the ecological significance of plant 
accumulators of aluminum, and (3) the role 
of aluminum in plant metabolism and its re- 
lation to plant tolerance and toxicity. It is the 
purpose of this paper to discuss data on a 
selection of Hawaiian plants with emphasis 
on the latter two questions. The floristics and 
ecology of study sites on gibbsitic soils will 
be considered later. 
REVIEW OF LITERATURE 
Much of the early development of infor- 
mation concerning aluminum in plants was 
stimulated by the interest in plant materials 
as mordants for the dye industry. Aluminum 
is one of the most abundant elements in the 
soil and is almost universally present in plants 
but varies widely in amount. Robinson and 
Edington (1945) deline an "accumulator” 
plant as one which takes up "the particular 
element in quantities very far above, some- 
times many thousands of times above, the 
average for 'normal’ plants.” If the mean 
A1+++ content of herbaceous vegetation is 
taken to be about 0.02 per cent of the dry 
matter (Hutchinson, 1943) or 200 p.p.m., the 
criterion of 1000 p.p.m. or 0.1 per cent used 
by Webb (1954) in a semiquantitative test 
Published with the approval of the Director of the 
Hawaii Agricultural Experiment Station, University of 
Hawaii, as Technical Paper No. 431. Manuscript re- 
ceived September 4, 1958. 
^ Assistant Agronomist, Junior Soil Scientist, and 
Head of Agronomy and Soil Science, Hawaii Agricul- 
tural Experiment Station, respectively. 
would seem to be adequate to qualify a plant 
as an aluminum accumulator. Many workers 
have reported aluminum contents of non- 
accumulator plants, corn for example (Meyer 
and Anderson, 1952), that equal this level. 
Several studies have attested to the variability 
of aluminum content within individual plants, 
usually with higher concentrations in roots 
and stems than in leaves and variability within 
a species when grown on different substrates 
(Webb, 1954). The extensive work of Webb 
and of Chenery (1948, 1948^, 1951) on local 
and world-wide floras has resulted in compila- 
tion of lists of aluminum accumulators. The 
highest content of aluminum found in plant 
tissue is reported for Symplocos spicata (Webb, 
1954), 7.1 per cent, and for a Carpinus species, 
8.5 per cent (Howard and Proctor, 1957). Mas- 
sive deposits of almost pure aluminum suc- 
cinate have been found in the heartwood 
cavity of Cardwellia sublimis (Webb, 1953) 
and Orites excelsa. Costin (1954) stated Poa 
caespitosa to have an aluminum content of 
7.8-10.4 per cent and showed that it produced 
a material richer in sesquioxides than the 
parent rock from which the soils of the region 
were derived. 
Chenery (1951) challenges the emphasis of 
some Russian workers on the role of alumi- 
num accumulators in podzolization and offers 
other explanation for the observed soil alu- 
minum distribution. Howard and Proctor 
(1957) studied the floristics of the bauxitic 
soils of Jamaica and found few of the families 
of accumulator species in Jamaica and fewer 
still on the bauxitic soils. They used neither 
tissue nor soil analyses but reported no spe- 
cies they could call indicators of aluminum 
and, on the contrary, concluded that factors 
other than the aluminum content of the soil 
controlled the success or failure of plants on 
Jamaican bauxite. 
335 
