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Lathyrus
See list of 10 species in this genus-
1a. Leaves lacking leaflets, reduced to a tendril; corollas yellow
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1b. Leaves with 2 or more well-developed leaflets; corollas white to ochroleucous or pink-purple to purple (yellow only in L. pratensis, a species with racemes of 4–10 flowers vs. solitary or rarely paired in L. aphaca)
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2a. Leaves with 4–16 leaflets [Fig. 641]; native plants
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3a. Stipules ± symmetrical, with 2 basal lobes, approximately equal in size to the leaflets; leaflets fleshy; legumes mostly 8–11 mm wide
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3b. Stipules asymmetrical, with 1 basal lobe [Fig. 641], definitely smaller than the leaflets; leaflets scarcely fleshy; legumes 4–7 mm wide
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4a. Corollas pink-purple to purple; raceme with 3–6 flowers; stipules 1–10 mm long, semisagittate (i.e., with a sharply pointed basal lobe); leaflets elliptic to elliptic-oblong, 2.5–9 times as long as wide
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4b. Corollas white to ochroleucous; raceme with 5–15 flowers; stipules 15–30 mm long, some semicordate (i.e., with a rounded or bluntly pointed basal lobe); leaflets ovate to elliptic, 2–2.4 times as long as wide
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2b. Leaves with 2 leaflets [Fig. 640]; non-native plants originating from cultivation
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5a. Plants annual, without rhizomes; inflorescence with 1–3 (–4) flowers
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6a. Leaflets linear to broad-linear; legume glabrous; flowers usually solitary, not especially fragrant
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6b. Leaflets ovate or elliptic; legume pubescent; flowers 1–3 (–4) in a raceme, very fragrant
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5b. Plants perennial, with rhizomes; inflorescence with (3–) 4–10 flowers
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7a. Corollas 14–25 mm long; legumes 40–100 ×6–10 mm; stems conspicuously winged
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8a. Stipules 3–10 mm wide, lanceolate to ovate [Fig. 640]; leaflets ovate to lanceolate; corollas 18–25 mm long
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8b. Stipules 1–2 (–4) mm wide, narrow-lanceolate; leaflets oblong-lanceolate to narrow-lanceolate; corollas 13–20 mm long
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7b. Corollas 10–15 mm long; legumes 20–50 ×4–7 mm; stems without prominent wing-angles
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9a. Corolla yellow; stipules 10–30 mm long; calyx lobes subequal in length, slender
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9b. Corolla red-purple; stipules 5–12 mm long; calyx lobes unequal, broad and short
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Show photos of:
Each photo represents one species in this genus.