18 
PACIFIC SCIENCE, VoL XIX, January 1965 
long as the branchlet diameter, separated by two 
obvious peripheral nodal cells; where bract-cells 
are not developed, the peripheral nodal cells 
form a ring. Bracteoles , none noted. Bractlet, not 
noted. Heads uncommon, but antheridial branch- 
lets are occasionally reduced forming loose heads 
3-5 mm in diameter. Gametangia on separate 
plants, at 1-2 lowest branchlet nodes and occa- 
sionally 1 per branchlet on inside of whorl at 
base of branchlets; mature antheridia commonly 
on small whorls congested into heads. Oogonia 
(1-) 2-3 at the lowest 1-2 branchlet nodes, 
780-1080 /x long (excluding coronula) by 610- 
680 fA wide; convolutions 6-7 (-8); coronula 
100-105 /x high by 140-180 /x wide at base, 
5 -celled in 1 tier, the cells triangular. Oospores 
black, (560-) 600-660 g long, 470-580 /x 
wide; striae of (5-) 6 broad ridges; fossa 105- 
130 /x across; membrane opaque and apparently 
smooth. Antheridia 2-3 at a node, (280-) 480- 
580 [x in diameter, generally borne on reduced 
branchlets but occasional at normal branchlet 
nodes; 8-scutate. 
C. corallina is easily recognized in Fiji in the 
field by the crisp turgid nature and large size, 
and by having both undivided branchlets and 
totally uncorticated axes. Nitella furcata , al- 
though sometimes difficult to differentiate in the 
field in depauperate examples, is generally dis- 
tinguishable by having forked branchlets and the 
tiny 2 -celled, abbreviated dactyls. When the 
two species are mixed (e.g„ spec, t), the two 
may appear to be one confusing species. 
This is essentially the G. australis f. vitiensis 
of earlier writers. C. australis was distinguished 
from C. corallina by being dioecious; but the 
writer’s investigations (MSS) indicated that in 
two otherwise indistinguishable "species” dioe- 
ciousness is a genetic state (half of the normal 
chromosome number) which may occur at ran- 
dom and is not a species distinction. Therefore, 
the monoecious C. corallina and dioecious C. 
australis were united (Wood, 1962^:12), and 
the oldest name, C. corallina , is employed. Speci- 
mens exhibiting the dioecious condition are here 
designated as "dioecious strains.” 
The Fiji specimens seem fairly unusual be- 
cause of the small stature, slender structure, and 
occurrence of two rather than one stipulodes per 
branchlet. They also appear to have small an- 
theridia (480-580 /x) for a dioecious strain (see 
Queensland, 800-1000 /x, and Tasmanian, 1250 
/x, examples), and to have the axial nodes un- 
usually swollen and congested with white ma- 
terial. It may prove to merit varietal status. The 
holotype of £. vitiensis was apparently destroyed 
in Berlin; and, as no duplicates have as yet been 
found, the writer suggests that specimen r (us) 
be accepted as the NEOTYPE. 
The chromosome number of 14 is consistent 
with earlier reports of Macdonald and Hotch- 
kiss (1956:277) who found 14 and 28, respec- 
tively, for dioecious and monoecious material 
from Australia. The second author’s further un- 
published counts of Australian "species” also 
appear to conform to this pattern. 
Variations among collections were not great, 
but at two extremes are examples which seem 
to depend for their structure upon ecological 
conditions. One is small and slender with short 
branchlets, the axis less than 580 /x in diameter, 
the plants generally 12 (rarely 20) cm high, 
and the branchlets up to 2 cm long ( see spec, 
e-i). The second is stouter, taller, and with 
longer branchlets, the axis 650-980 /x in diam- 
eter, the plants up to 30 cm high, and the branch- 
lets commonly 3 (rarely to 6) cm long (spec, 
r). The latter appears to be a lush expression 
which develops in rich, shaded conditions such 
as in lily pools, while the former develops in 
exposed water of wet rice fields. In addition to 
these extremes, see spec, k which exhibits well- 
developed antheridial heads, and spec, f which 
has basal oogonia. 
HABITATS: Rice fields, ponds, drainage ditch, 
pool by bridge, water lily pool, creek, river. 
DISTRIBUTION: In Fiji, collected on Viti Levu 
(Nadroga, Naitasiri, Tailevu), Ovalau, and Va- 
nua Levu (Macuata near Labasa, Natua, Macu- 
ata-i-wai, and Cakaudrove near Savusavu). G. 
corallina is restricted to the eastern hemisphere, 
where it is widely distributed in the tropics and 
extends into the temperate regions (especially 
of the southern hemisphere). It is reported from 
Africa, Mauritius, India, Ceylon, Burma, Thai- 
land, Japan, Philippines, Indonesia, Australia 
(including Tasmania), New Caledonia, New 
