1919] Clokey,— Carex Notes 85 
clavate at base, 6-12 mm. long including.staminate part (frequently 
constituting one third or more of the longer spikes), 3-6 mm. wide, 
irregularly separated to approximate. Bracts absent or the lower 
1-3 present, setaceous, shorter or longer than the head. Staminate 
flowers basal. Perigynia 3-4 mm. long .9-1.25 mm. wide, straw- 
colored over achene, rest light green to straw-color, thin, scale-like, 
scarcely distended over the achene, several-nerved on each face, 
straight, tapering to slightly cleft apex, without well-marked beak. 
Achene 1-1.25 mm. long, .67-.75 mm. wide, dull straw-color, lenticular, 
elliptical, short-stipitate; style slender. Scale white-hyaline with 
green midrib to uniform straw-color, acute, .67-.75 the length of the 
perigynia, narrower than the perigynia. Stigmas 2. 
This well marked plant is found growing in rich alluvial soil in two 
small widely separated areas in Macon County, Illinois. My number 
2364, preserved in my herbarium, is designated as the type. My 
number 2362 also belongs here. At the type-locality the plant is 
found growing with Carex Leavenworthii Dewey, and C. muskingum- 
ensis Schwein. lt may be separated from the typical form of C. 
tribuloides Wahl., and from Bailey's varieties turbata and reducta by 
the following key. 
Spikes 3-7; leaves 1.5-4 mm. broad........ C. tribuloides, v. sangamonensis. 
Spikes 8-14; leaves 3-8 mm. broad. 
Perigynia with appressed tips. 
Inflorescence moniliform, spikes scattered....C. tribuloides, v. turbata. 
Inflorescence cylindric, spikes approximate... .C. tribuloides (typical). 
Perigynia with spreading tips, inflorescence flexuous. 
C. tribuloides, v. reducta. 
Var. sangamonensis is in some respects between varieties turbata 
and reducta, in others different from all other forms of the species. A 
large number of specimens show that the tips of the perigynia are 
frequently straight with the perigynia slightly spreading, not appressed 
as in var. turbata, nor recurved as in var. reducta. Many of the heads 
show a flexuous inflorescence with decidedly separated spikes. The 
small number of spikes is a regular thing, not an exception. Out of 
several hundred plants carefully examined, only 2-3 heads were found 
with 8 spikes, a relatively small number with 3 or 7 spikes, and proba- 
bly over 90% with 4-6 spikes. Another point of difference is in the 
perigynia which, when fully mature, measure 3-4 mm. with the 
average of 3.5 mm. long. 
DENVER, COLORADO. 
