Hawaiian Hibiscus—- Roe 
29 
flowered Kauai hibiscus was distinct from both 
H. Arnottianus and H. Kokio, and he described 
it as H. waimeae. 
In 1900 Hochreutiner published his revision 
of the genus Hibiscus, including the Hawaiian 
species. He presented a new interpretation of 
H. Arnottianus. While Hillebrand and Heller 
had applied Gray’s description to the plant col- 
lected during Beechey’s voyage, Hochreutiner 
felt that the name H. Arnottianus belonged to 
the plant collected by Diell, called by Hillebrand 
H. Kokio. 
Hochreutiner classified the plants in question 
as follows: 
H. Waimeae Heller 
var. Hookeri Hochr. 
var. Heller i Hochr. 
(white-flowered 
species) 
(Beechey plant) 
(Kauai white) 
H, Arnottianus Gray (red-flowered species) 
var. Kokio Hochr. (Hillebrand’s 
H. Kokio ) 
var. genuinus Hochr. 
(Byron’s Bay- red- 
Macrae, Diell) 
Rock (1913^) makes no mention of Hoch- 
reutiner ’s revision, which leads one to believe 
that he was not familiar with it. He was aware, 
however, of the original problem regarding H. 
Arnottianus and, to verify his classification, he 
sent a specimen of the white-flowered H. Ar- 
nottianus to the Gray Herbarium, where B. L. 
Robinson made comparisons and replied, "There 
can be no question that the white-flowered 
species (No. 8831) from Oahu is precisely the 
real H. Arnottianus Gray.” As far as Rock was 
concerned the case of H. Arnottianus was set- 
tled. However, in 1914, T. A. Sprague began 
again to dispute its nomenclature. He wrote 
in the Kew Bulletin, "So much confusion has 
arisen in the past in connection with the name 
H. Arnottianus that it is perhaps desirable to 
abandon the use of it altogether.” Sprague 
claimed that Gray had a red-flowered species in 
mind when describing H. Arnottianus, for he 
sent a specimen of this species collected by Diell 
to Sir William Hooker under the name H. Ar- 
nottii Gray (later altered to Arnottianus) . How- 
ever, Sprague disregarded the name H. Arnot- 
tianus entirely and retained H. Kokio Hbd. for 
the red-flowered species. 
Skottsberg (1926), in reviewing the nomen- 
clatural history of H. Arnottianus, exclaimed, 
"The confusion is very complete.” His conclu- 
sion, however, is very sound and offers the only 
logical solution to the problem. He rebuked 
Hochreutiner and Sprague for their "inadmis- 
sible” treatment given to the species in ques- 
tion, and joined Rock in his view of the situa- 
tion. 
It is concluded that Gray had two species on 
hand when he described H. Arnottianus — the 
white-flowered Oahu hibiscus bearing the long 
staminal column, and the small red-flowered 
plant. The red plant was the material sent to Sir 
William Hooker and the white-flowered species 
was retained in the Gray and the U. S. National 
Museum herbaria. This white species compares 
to our Oahu white according to the judgment 
of Dr. Robinson. In a recent letter, Reed C. 
Rollins, director of the Gray Herbarium, also 
testified that H. Arnottianus from the Wilkes 
Expedition is "white-flowered, with a very long, 
apparently red, staminal column.” 
Likewise, Richard S. Cowan of the U. S. 
National Museum, in a letter dated June 28, 
1958, confirmed this belief regarding the mate- 
rial deposited there. Cowan wrote: 
We have one sheet bearing one flowering 
branch collected by the U. S. Exploring Ex- 
pedition; the label is the standard label for this 
Expedition but the locality is in long-hand and 
reads: "Oahu, S. Islands.” The only other nota- 
tion is the name "Hibiscus Arnottianus Gray.” 
I have compared both the quoted items with a 
scrawl of Gray’s in our holograph collection 
and I feel certain that they were made by the 
same person. There is no question in my mind 
that the specimen is of the white-flowered 
element, for red-flowered H. Kokio clearly shows 
red flowers even in the dried condition. The 
length of the staminal column in one of the 
two flowers on our specimen is 10.5 cm. In most 
respects, this specimen appears very similar to 
the following collections in our herbarium as- 
signed to H. Arnottianus: Mann & Brigham 
530 and Christopherson 1373. 
