394 
PACIFIC SCIENCE, Vol. XVIII, October 1964 
florets of Prosopis and certain other leguminous 
shrubs (Namba, 1956:100). As a consequence 
the relatively flower-constant honeybee has been 
forced to forage among a variety of nectar ( and 
pollen) sources. 
The village of Nanakuli is located on a 
crescent-shaped coastal plain of western Oahu, 
bounded by the Waianae Range which juts into 
the sea to the north at Maile Point and to the 
south at Kahe Point. The lower slopes of the 
range are dominated by a zone of Prosopis 
scrub, and where this zone approaches the coast, 
populations of tomentosum are very common 
in the understory. Occasional barbadense plants 
occur along the coastal highway which runs 
through Nanakuli, and also in gardens in the 
village itself. In two small areas, (a) south of 
Piliokahe Beach and (b) in a waste lot adjoining 
the Texaco Service Station in the village, out- 
lying plants of tomentosum and barbadense are 
growing within 50 yards of each other. Less 
than a quarter mile inland, two colonies of 
honeybees are established in hives under the 
Prosopis trees. And in the areas where tomen- 
tosum and barbadense are in close proximity, 
two obviously hybrid populations are found 
whose taxonomic properties are illustrated by 
the data presented in Table 2 and Figure 4. 
Table 2 gives the results of scoring the popu- 
lations for four qualitative or semiqualitative 
characters which distinguish the two species. 
The scoring was necessarily limited to those 
plants which were flowering at the time the 
study was made. The 1 1 plants scored include 9 
different combinations of characters, none of 
which was identical with either parental com- 
bination. The populations were therefore segre- 
gating for characters which distinguish the two 
species. 
The plants were also scored for certain metri- 
cal characters which previous experience has 
shown to be useful in discriminating between 
species of New World cottons. These are pre- 
sented as a scatter diagram in Figure 4, according 
to the methods developed by Anderson ( 1949: 
81-101). The characters measured are listed 
below; methods of measurement will be found 
in the Appendix to this paper: 
Br. T. — Number of bract teeth 
Br. D. — Bract dissection index 
Br. S. — Bract size 
L. I. — Leaf index 
P. L. — Petal length 
S. L-— Staminal index 
In Figure 4 staminal index is plotted on the 
horizontal axis, petal length on the vertical axis. 
The other characters are symbolized according 
TABLE 2 
Hybrid Cotton Populations at Nanakuli, Oahu; Segregation in Qualitative Characters 
Symbols used: H (tomentum); Ne (leaf nectary); Y (bright yellow petal); R (petal spot). Presence of each 
character is indicated by ( + ), absence by (o) and intermediate condition by ( — ). 
H 
Ne 
Y 
R 
tomentosum 
+ 
o 
+ 
o 
Parent type; in Prosopis 
+ 
o 
+ 
o 
scrub south of Nanakuli 
Hybrid No. 1 
- 
- 
+ 
- } 
. 
2 
+ 
— 
o 
o 
L Waste ground near service 
3 
o 
— 
+ 
- 1 
| station, Nanakuli 
4 
o 
+ 
+ 
+ J 
5 
— 
+ 
— 
u 
7 
8 
9 
o 
o 
o 
+ 
+ 
+ 
Roadside behind Piliokahe 
Beach, Nanakuli 
10 
+ 
— 
+ 
+ 
11 
— 
o 
+ 
+ 
barbadense 
o 
+ 
— 
+ 
Parent type; Dooryards, 
o 
+ 
Bvl 
o 
Nanakuli 
