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Coreopsis
See list of 10 species in this genusReference: Strother (2006b).
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1a. Disk corollas mostly 4-lobed at apex; outer series of involucral bracts much shorter than the inner series [Fig. 394]; style branch apex blunt or short-conical
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2a. Rays pink to white; disk corollas yellow; cypsela body lacking wing-like edges; principal leaf blades usually simple (rarely with 2 or 3 lobes) [Fig. 394]; plants perennial, from rhizomes
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2b. Rays yellow distally with a red-brown base; disk corollas dark red; cypsela body narrowly to broadly winged (infrequently wingless); principal leaf blades 1- to 2-times pinnatifid; plants annual or biennial, from taproots
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1b. Disk corollas mostly 5-lobed at apex; outer series of involucral bracts nearly or fully as long as inner series (shorter in C. tripteris); style branch apex acute, long-conical, or cuspidate
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3a. Leaf blades simple or pinnately lobed to compound with 3–9 (or more) segments [Fig. 392]; chaff long-attenuate at apex; rays apically with prominent tooth-like lobes
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4a. Disk corollas dark red; principal leaf blades pinnately lobed or pinnately compound with oblong to broad-ovate segments
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4b. Disk corollas yellow; principal leaf blades simple or with a pair of basal lobes or pinnatifid with linear to narrow-lanceolate lobes
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5a. Leaves confined to lower portion of stem; peduncles elongate, scape-like, mostly 20–40 cm long
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5b. Leaves borne throughout the stem; peduncles relatively shorter, mostly 5–20 cm long
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6a. Principal leaf blades pinnatifid into linear to narrow-lanceolate segments; pappus often wanting
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6b. Principal leaf blades simple, elliptic to obovate or ovate, sometimes with a pair of smaller lobes at the base; pappus often of 2, short, scale-like teeth
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3b. Principal leaf blades palmately or ternately lobed or divided (the central segment sometimes again palmately or ternately lobed or divided) [Fig. 393]; chaff rounded to acute at apex; rays apically entire or shortly toothed
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7a. Leaf blades borne on evident, narrow petioles that are clearly much narrower than the associated leaf segments; outer involucral bracts 2–3 mm long, ca. ⅓ to ½ as long as the inner involucral bracts; reproductive stems 10–30 dm tall
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7b. Leaf blades sessile or borne on petiole-like structures that are nearly or fully as wide as the associated leaf segments; outer involucral bracts (3–) 4–12 mm long, subequal in length to the inner involucral bracts; reproductive stems 3–10 dm tall
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8a. Ultimate segments of leaf blades linear to filiform, 0.3–1.5 mm wide; cypsela body 3–5 ×1–1.7 mm
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8b. Ultimate segments of leaf blades linear to oval, 2–25 (–30) mm wide; cypsela body 4.5–6.5 ×1.8–4 mm
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9a. Leaf blades trifurcating well above the base (i.e., the blades appearing to be on a broadly winged petiole) into linear to narrow-oblong segments 2–7 mm wide [Fig. 393]; internodes of stem usually glabrous
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9b. Leaf blades trifurcating at the base (i.e., the leaf blades definitely sessile) into lanceolate to oval segments (5–) 12–25 (–30) mm wide; internodes of stem usually short-pubescent
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Each photo represents one species in this genus.