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PACIFIC SCIENCE, Vol. IV, July, 1950 
nature of the substances which are present 
in the plant juices. In other words, and as 
herbalists and pharmaceutists long ago real- 
ized, it is the possession of chemical proper- 
ties peculiar to itself that makes a plant dif- 
ferent from its neighbors and superior to 
some of them for use as a medicine. The 
medicinal plants in Hawaii are no exception 
to this obvious rule. We are not able to say 
what substances in the tissues of the more 
effective of the Hawaiian plants are respon- 
sible for their efficacy. 
The results of the tests with the actual 
extracts show that of the 101 species studied, 
13 possess a considerable degree of effective- 
ness against the test bacteria (Table 3). Four 
of these plants — koa, Acacia Koa; mountain 
apple, Eugenia malaccensis; ohia lehua, Me- 
trosideros macropus ; and guava, Psidium 
Guajava — the Hawaiians have employed in 
the treatment of cuts and wounds and "skin 
diseases,” or of bacterial infections like "diar- 
rhoeas and dysenteries,” but most of the 
others are plants which do not appear to have 
played much of a part in the treatment of 
conditions caused by bacteria. Most of them — 
Alpinia purpurata, Tamarindus indica, Citrus 
aurantifolia, Hura crepitans , the three Passi- 
flora species, and Punica Granatum — do not 
seem to have been used at all by the Hawai- 
ians, possibly because of their relatively re- 
cent introduction into Hawaii. One plant, the 
uluhe, Dicranopteris linearis, was used by the 
Hawaiians as a laxative, but not, as far as 
we know, in the treatment of conditions in 
which bacteria were implicated as the caus- 
ative agents. All of these plants are worthy 
of further study to see if it is possible to ob- 
tain from any of them a useful antibacterial 
substance. 
An even greater number of plant species 
is moderately effective in the action against 
the test bacteria (Table 4). Among these 
are several of the more famous and the more 
favored of the Hawaiian remedies: the kukui, 
Aleurites moluccana\ the popolo, Solanum 
nodiflorum; the noni, Morinda citrifolia ; the 
laukahi, Plantago major. ; and Bidens pilosa, 
a relative of the native "tea,” ko’oko’olau. 
All of these plants had a great number of 
uses in Hawaiian medicine, and the popolo 
in particular has been called "ke kumu o ka 
lapaau o Hawaii nei” — "the foundation of 
Hawaiian pharmacy” (Handy et ah, 1934: 
18 ) . The juices of its leaves and berries were 
used, either alone or in combination with 
other ingredients, for diseases of the skin, in 
the treatment of cuts and wounds, in "dis- 
orders of the respiratory tract,” and for "ton- 
ing up the digestive tract” (Handy et ah, loc. 
cit . ) . 
Our studies showed that each of the favor- 
TABLE 5 
Extracts Which Exhibit Slightly Effective Antibacterial Properties 
( with zones of inhibition less than 10 mm. in diameter) 
NAME OF PLANT 
PART OF PLANT 
PROVIDING EXTRACT 
pH 
OF EX- 
TRACT 
DIAMETER OF ZONES OF 
M. 
pyogenes E. coli 
INHIBITION 
Ps. aeru- 
ginosa 
Cihotium Chamissoi 
stems of fronds 
5.1 
0 
0 
8 
B ambus a sp. 
leaves and stems 
qns 
7 
0 
0 
Peperomia latifolia 
whole plant 
5.7 
0 
0 
8 
PittosporumT obira 
bark* 
6.2 
0 
0 
8 
leaf* 
6.1 
0 
0 
9 
Sida fallax 
stems 
6.2 
9 
0 
0 
Waltheria americana 
water extract of 
leaves and stems 
5.5 
0 
0 
8 
Eugenia malaccensis 
stems 
4.3 
8 
0 
0 
Lantana Camara 
leaf 
7.3 
8 
0 
not tested 
* See Table 6. 
