14 
PACIFIC SCIENCE, Vol. XV, January 1961 
SUMMARY OF DISTINGUISHING CHARACTERS 
OF H. Brackenridgei POPULATIONS 
Upon observation of the H. Brackenridgei 
populations, it is evident that four groups are 
distinct. Var. molokaiana stands apart for its 
long petioles and small, deeply lobed leaves; var. 
kauaiana has larger leaves, entire to shallow 
lobed; and var. mokuleiana is definitely arbores- 
cent, bearing larger flowers. Table 2 compares 
the differentiating characters. 
6. Hibiscus Kokio Hbd. 
Figs. 9-11 
Hibiscus Kokio Hillebrand. Flora of the Ha- 
waiian Islands, p. 173. 1873. 
H. Boryanus Hook & Arn. Bot. Beechey Voy., 
p. 79. 1841. 
H. Arnottianus A. Gray in Bot. U. S. Expl. 
Exped. 1: 176 (pro parte). 1854. 
H. Arnottianus var. Kokio Hochr. Ann. 
Conserv. Jard. Bot. Geneve 4: 133. 1900. 
H. Arnottianus forma Sinclair. Indig. FI. Haw. 
Isl, p. 9. 1885. 
DESCRIPTION: Tall shrub with straggly 
branches from the base, growing to 20 ft.; few 
lateral branches. Stipules 8 mm. long, glabrous. 
Petioles, 2-4 cm. long. Leaves 9-12 cm. long, 
4-6 cm. wide, elliptical-ovate, long-acuminate 
apex, margin sinuately crenate, smooth surface, 
scarcely palmately veined. Peduncle 3.0 cm., 
articulate 5 mm. from involucre base. Involucre 
6-7 lanceolate bracts, 1.3 cm. long, 1.5 mm. 
wide, slightly puberulent. Calyx 2. 5-2. 8 cm. 
long, 1.3 cm. wide, 10-veined, cleft 1 cm. from 
tips, 5 lobes, lanceolate, no glands, "lettuce green” 
in color, glabrate. Flowers axillary. Staminal 
column 5.5 cm. long, "scarlet red.” Free filament 
tips extend 4 mm. from column, occupy apical 
1.5 cm. of column. Style extension 4 mm.; style 
branches (horizontal) 8 mm. long. Petals 5.5 
cm. long, 3.5 cm. wide, "scarlet red.” Ovary 
truncate-conical, 6 mm. long, 4 mm. wide, 
pubescent (short, colorless hairs). Capsule gla- 
brous, 2.5 cm. long. Seed reniform, 4 mm. long, 
brown, coarsely pubescent. 
The nomenclature of this taxon is closely 
correlated with that of H. Arnottianus Gray. A 
discussion of their confusion can be found in 
the section of this paper dealing with the latter 
species. Gray’s original description of H. Ar- 
nottianus included a fragment of a red-flowered 
hibiscus as well as the white. 
TABLE 2 
Distinguishing Characters of H. Brackenridgei Population 
CHARACTERS 
H. Brackenridgei 
VAR. molokaiana 
VAR. kauaiana 
VAR. mokuleiana 
Growth habits 
shrub 
rambling shrub 
rambling shrub 
tree to 30 ft. 
Leaf lobing 
deeply cleft (5-7) 
deeply cleft (5) 
shallow-lobed (3) 
moderately lobed 
Leaf length 
5 cm. 
3-5 cm. 
7-9 cm. 
9-1 1 cm. 
width 
5 cm. 
5-6 cm. 
7-9 cm. 
8-10 cm. 
Stipules 
0.5-1 cm. long 
1 cm. long 
1 cm. long 
1—2 cm. long 
Petiole 
nearly glabrous 
puberulent 
densely pubescent 
puberulent 
Bract number 
8-10 
8-9 
5 
7-8 
Bract shape 
setaceous, terete 
subulate, terete 
hastate, not terete 
subulate, terete 
Bract glands 
none 
glands on inner 
side 
none 
none 
Bract surface 
almost glabrous 
hirsute 
hirsute 
hirsute 
Bract length 
1 cm. 
2.5 cm. 
3.0 cm. 
2-3 cm. 
Calyx venation 
1 0-veined 
5 -veined 
5 -veined 
10-veined 
Calyx length 
1.5 cm. 
1.5 cm. 
2.5 cm. 
3—4 cm. 
width 
1.5 cm. 
1.0 cm. 
1-1.5 cm. 
1.5 cm. 
Calyx glands 
present 
none 
present 
none 
Petal length 
3.5 cm. 
5.0 cm. 
6.0 cm. 
8-10 cm. 
width 
2.5-3 cm. 
4.5 cm. 
5.0 cm. 
5-8 cm. 
Column length 
4.0 cm. 
4-5 cm. 
2.5 cm. 
7-8 cm. 
naked at base for 1 
naked at base for 1 
completely antheri- 
completely 
cm. 
cm. 
ferous 
antheriferous 
