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Lepidium
See list of 11 species in this genusLepidium ramosissimum A. Nels. was reported from ME by Rollins (1993), but specimens are unknown. Reference: Al-Shehbaz and Gaskin (2010).
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1a. Silicles with a wrinkled texture due to raised veins or reticulum; racemes borne laterally from the axils of leaves
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2a. Silicles with an evident basal and apical sinus, reticulate to rugose over the exterior surface [Fig. 521]; styles obsolete
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2b. Silicles lacking both basal and apical sinuses, coarsely veined and with protruding, wart-like processes over the exterior surface; styles present, ca. 0.5 mm long
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1b. Silicles with a smooth surface; racemes chiefly terminal and at the tips of branches
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3a. Silicles without a notch at the apex; plants perennial from rhizomes or stolons
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4a. Leaf blades sagittate-clasping; silicles subglobose; flowering raceme typically flat or sometimes even concave-topped, the lower pedicels equaling the height of the inflorescence; plants 2–5 dm tall
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4b. Leaf blades shortly petiolate or sessile, but not clasping the stem; silicles flattened perpendicular to the septum; flowering raceme typically round-topped, the lower pedicels shorter than the height of the inflorescence; plants (5–) 7–13 dm tall
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3b. Silices with a notch or sinus at the apex; plants annual from taproots or fibrous roots
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5a. Stem leaves either sagittate- or cordate-clasping [Fig. 520]; flowers with 6 stamens
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6a. Stem leaves cordate-clasping, the basal lobes rounded; lower leaf blades 2 or 3 times divided into linear segments; petals yellow, 1–1.5 mm long; fruiting pedicels glabrous; silicles ca. 3.5–4 mm long
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6b. Stem leaves auriculate-clasping, the basal lobes usually acute [Fig. 520]; lower leaf blades entire to toothed or sometimes once pinnately lobed; petals white, 1.8–2.8 mm long; fruting pedicels pubescent; silicles 5–6 mm long
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7a. Style 0.2–0.5 (–0.7) mm long, not or only shortly exserted beyond the apical notch of the fruit; valves of silique papillose; plants annual, without a caudex
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7b. Style (0.6–) 1–1.5 mm long, prominently exserted beyond the apical notch of the fruit; valves of silique usually not papillose; plants perennial, with a caudex
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5b. Stem leaves narrowed to the base, not surrounding the stem; flowers with 2 or 4 stamens except L. sativum with 6 stamens
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8a. Flowers with 6 stamens; silicles 5–6 mm long, prominently winged; cotyledons 3-lobed
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8b. Flowers with 2 (rarely 4) stamens; silicles 2–4 mm long, without a wing or winged only in the apical portion; cotyledons entire
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9a. Petals typically present, 1–2 times as long as the sepals [Fig. 522]; rachis of raceme, when pubescent, with curved, cylindrical hairs; cotyledons accumbent
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9b. Petals obsolete or rudimentary and shorter than the sepals; rachis of raceme pubescent with straight, cyclindrical to subclavate hairs; cotyledons incumbent
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10a. Racemes densely flowered, with 9–18 fruits per cm; silicles obovate to broad-obovate; plants inodorous; lower surface of fruiting pedicels smooth; seeds with an apical, narrow wing-margin
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10b. Racemes relatively sparsely flowered, with 6–10 fruits per cm; silicles elliptic; plants foul-scented; lower surface of fruiting pedicels sparsely papillose; seeds lacking a wing margin
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Each photo represents one species in this genus.