274 
PACIFIC SCIENCE, Vol. IV, July, 1950 
3170, Paauhau, June 24, 1909; Rock 3173 , 
Paauhau No. 1 Stream, 3000', June 24, 1909; 
Skottsberg 703, Kohala Mts. near Kamuela, 
Sept. 29, 1922, (GO); Skottsberg 393, S 
slope of Mauna Loa above Pahala, Sept. 19, 
1922, (GO). 
Carex pluvia R. Krauss, a member of sub- 
genus Eucarex, section Acutae Fries, subsec- 
tion Crypto carpae Tuckerman (Kukenthal 
1909: 297), stands close to Carex alligata 
F. Boott. It differs from the latter in the dull 
membranous to chartaceous bi-convex peri- 
gynia, which may bear setae on the rostrum 
and on the rostrum base, as in Forbes 301.H 
and Forbes 380. M. It is often 1-3-nerved 
from the stipitate base. This species is related 
to Carex laciniata F. Boott. It differs from 
Carex laciniata F. Boott primarily in the lack 
of the multiveined perigynia and in the more 
clearly bidentate rostrum; also, the peduncles 
are shorter and the internodes in the inflores- 
cence are much reduced in Carex pluvia. It 
is usually of smaller stature, about 50 cm. 
long, rarely reaching 75 cm. Certain spec- 
imens have been collected with the intact 
spikes bearing hundreds of germinated seeds 
(Krauss 380). 
The placing of the group as a species 
seemed at first to be questionable. Inasmuch 
as Carex pluvia and Carex sandwicensis were 
found growing together, especially on Maui, 
the possibility of wide biotypic variation 
seemed great. However, the plants growing 
in the same general areas seemed to have 
ecologic preferences, Carex pluvia in the wet 
shaded areas, often in running water, and 
Carex alligata in the drier sunny uplands. 
This suggested that they might be ecologic 
forms or varieties, but the distinctness of 
shape and surface of the perigynia, verified 
by repeated visits to the same plants as they 
matured, and the lack of intermediate forms 
between the two, although growing side by 
side, seem to eliminate this possibility. The 
distribution also gives some clue as to the 
constancy of the species. Carex pluvia is 
found alone on Oahu and together with Carex 
alligata on Maui, Hawaii, and Kauai. 
In spite of its distinguishing characters 
the species is probably a recent one. The dif- 
ferences within the specific limits, especially 
the occurrence of extremely large though 
caducous setae on the ridge running into the 
rostrum, are remarkable and would suggest 
another species to many taxonomists. 
Carex laxiflora Lam is an earlier name ap- 
plied to a different plant; therefore main- 
taining the epithet of the variety of Kuken- 
thal would create a later homonym. The 
epithet pluvia suggests the habitat in and 
along watercourses subject to flooding. It is 
the Latin adjective pluvius, meaning wet or 
rainy. 
Carex pluvia var. koolauensis var. nov. 
Figs. 15, l6a-b 
A specie differt in squamis radicorum 8-12 
mm. latis 1-11 cm. longis crassis persisten- 
tibus rubris aut purpureis culmis fertilibus 
2-4 mm. latis, 50-100 cm. longis erectis 
striatis, in apicibus scabris ad basim glabris, 
laminis viridibus sed ad basim, rubris aut 
purpureis vaginis lignosis rubris aut purpur- 
eis, inflorescentis 8-15 cm. longis erectis ra- 
mosis 7-11 nodis 103 spiciferis, internodis 
inferis 2-3 cm. longis superioribus breviori- 
bus, bractis-laminiferis inferioribus 30-45 
cm. longis superioribus brevioribus, peduncu- 
lis 3-7 mm. longis in ocreis purpureis lance- 
olatis inclusis, squamis foeminis utriculis ae- 
quantibus carinis dorsalibus 2-3 albi-nervosis 
in marginibus membranaecis purpureis, utri- 
culis 1-2 mm. latis 3-4 mm. longis incrassatis 
striatis ovoideis aut anguste oblongi-ovoideis 
purpureis-nigris fulgentibus stipitatis rostris 
I mm. longis bidentis, achaenis biconvexis 
obovoideis utriculis semi-complentibus rugo- 
sis aut glabris aureis. 
Differs from the species in the following 
characters: basal scales 8-12 mm. wide, 1- 
II cm. long, coarse, persistent, shiny, red to 
