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1 Lowest pistillate bract auriculate but not sheathing; terminal spike normally staminate (rarely with a few perigynia terminally); leaf blades 1-2 mm wide; basal sheaths purplish or red; [of cliffs and rock outcrops at moderate to high elevations in the Mountains]
1 Lowest pistillate bract sheathing (the sheath short in C. prasina); terminal spike normally gynecandrous, rarely merely staminate (often merely staminate in C. prasina); leaf blades 1.5-7 mm wide; basal sheaths purplish or red (brownish or greenish in C. prasina); [of various habitats, only rarely as above].
..2 Perigynia strongly trigonous, the lateral ribs at the angles, broadest below the middle; basal sheaths brownish or greenish; leaf sheaths glabrous on the hyaline ventral portion
....3 Perigynia densely white-hirsute; achenes brown with dark red spots
......4 Leaf sheaths glabrous on the hyaline ventral portion; larger leaves 3-9 mm wide
........5 Perigynia 2.5-3.0 mm long, 0.9-1.2 mm wide; perigynium beaks absent or very short, the orifice entire; leaf blades1.5-2.5 mm wide
..........6 Perigynia 3.0-4.0 mm long, 1.5-1.75 mm wide; leaves 2-4 mm wide
............ 7 Upper pistillate scales awned (awn 2.5-3 mm long); perigynia 4.5-6.0 mm long, 2.0-2.5 mm wide
............ ..8 All spikes gynecandrous, the lateral spikes with at least 1 staminate flower at base; peduncles longer than the pistillate spikes
............ ..8 Only the terminal spike gynecandrous, the lateral pistillate; peduncles shorter than the pistillate spikes