| | 1. Leaf blade with scales, with or without hairs, without glands |
| |
| | 2. Rhizome long-creeping, leaves well separated |
| |
| | 3. Rhizome scales ovate-lanceolate, sometimes toothed, pale reddish brown or 2-colored with a poorly defined mid-stripe |
| C. wootonii |
| | 3' Rhizome scales linear-lanceolate, ± entire, darkish or 2-colored with a well-defined midstripe |
| C. clevelandii |
| | 2' Rhizome short-creeping, leaves crowded |
| |
| | 4. Leaf blade linear-oblong; leaf segments ± round or generally oblong, scales on lower surface deeply dissected, long-ciliate |
| C. gracillima |
| | 4' Leaf blade oblong to narrowly triangular; leaf segments ± round, scales on lower surface entire to ciliate, generally covering more dissected scales |
| |
| | 5. Leaf segments glabrous on upper side, scales in immediate contact with lower surface dissected but with an obvious and relatively large body, scales of main axes generally > 1 mm wide |
| C. covillei |
| | 5' Leaf segments, or at least some, with deeply dissected scales on upper surface, scales in immediate contact with lower surface deeply dissected, with a body only 1–2 cells wide, scales of main axes generally < 1 mm wide |
| C. intertexta |
| | 1' Leaf blade without scales, with or without hairs, with or without glands |
| |
| | 6. Rhizome scales with darker mid-stripe |
| |
| | 7. Hairs on leaf segment upper surface very dense, intertwined; darker mid-stripe of rhizome scales thread-like, < 0.1 mm wide at base; 1° leaflet stalk 1–2(5) mm; 2° leaflet stalk generally brownish on upper, lower surfaces |
| C. parryi |
| | 7' Hairs on leaf segment upper surface sparse, generally not intertwined; darker mid-stripe of rhizome scales not thread-like, > 0.1 mm wide at base; 1° leaflet stalk ± 0–1 mm; 2° leaflet stalk greenish on upper surface, brownish on lower |
| C. feei |
| | 6' Rhizome scales without darker mid-stripe |
| |
| | 8. Leaf surface with ± clear, sticky exudate, generally with sessile or short-stalked glands |
| C. viscida |
| | 8' Leaf surface without sticky exudate, with short or long, glandular or non-glandular hairs |
| |
| | 9. Rhizome scales of 2 kinds, some maroon with a tan, curly, hair-like tip, others tan ± throughout, narrower; leaf segment lower surfaces not visible through very dense, tangled, non-glandular hairs; rhizome short- to long-creeping |
| C. newberryi |
| | 9' Rhizome scales of 1 kind, tan to reddish brown ± throughout; leaf segment surfaces visible through ± sparse, untangled, glandular and non-glandular hairs; rhizome short-creeping |
| C. cooperae
|