I have now keyed a specimen of this out vs. C. vacillans, and am confident that it is C. recta. The dark margins of the pistillate scales are ~bronzy-brown (vs. almost purple-black in C. vacillans) and with a broad pale zone (>33% of total width at bottom). The perigynia are nerveless or very obscurely nerved (vs. distinctly 3-5 nerved in C. vacillans) and lacking scabrules at the beak. The achenes are strongly folded on one face.