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Sedum
See list of 8 species in this genusSedum has been shown to be highly artificial (i.e., non-monophyletic) and has been split into smaller, more homogeneous genera that better reflect the evolutionary history of the family (’t Hart 1995, Ohba 2009). Recognized here apart from the broadly defined Sedum are Aizopsis, Hylotelephium, Phedimus, and Rhodiola. Reference: Ohba (2009).
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1a. Upper stem and axis of inflorescence stipitate-glandular; petals white and usually some with a pink or green midstripe; flowers with both 6- to 9-merous corollas and horizontally spreading mature carpels; plants annual or biennial (rarely short-lived perennial)
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1b. Upper stem and axis of inflorescence glabrous (though stipitate-glandular near base of plant in S. album); petals yellow to yellow-white or entirely white; flowers not combining the stated characters, with either 4- or 5-merous corollas, or erect follicles, or both; plants perennial
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2a. At least the leaves of the sterile shoots and basal portion of reproductive shoots whorled (i.e., 3 at each node) or less frequently opposite [Fig. 599], the blades relatively flat
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3a. Petals yellow; flowers mostly 5-merous; leaf blades elliptic-oblanceolate to oblong-lanceolate or narrow-ovate
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3b. Petals white; flowers mostly 4-merous; leaf blades obovate (except the upper ones of reproductive shoots, which are oblanceolate to ± linear)
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2b. Leaves alternate, sometimes tightly imbricate and the arrangement difficult to discern, the blades strongly biconvex to subterete in cross-section
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4a. Flowers (5–) 6- or 7 (–9)-merous; leaf blades pointed or apiculate at the apex; follicles erect
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5a. Sepals 5–6 mm long, lanceolate to broad-lanceolate, acute to acuminate at the apex, slightly concave on the abaxial surface; petals cream to green-white or white-yellow, 8–10 mm long
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5b. Sepals 1.5–3 mm long, ovate, acute or obtuse at the apex, not concave on the abaxial surface; petals bright yellow, 6–7 mm long
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4b. Flowers usually 5-merous; leaf blades blunt at the apex; follicles divergent (erect in S. album)
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6a. Petals white; follicles erect; leaf blades 4–20 mm long
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6b. Petals yellow; follicles divergent; leaf blades 2–6 mm long
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7a. Leaf blades ovoid, not arranged in consistent vertical ranks; petals 6–8 mm long
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7b. Leaf blades narrow-cylindric, arranged in 6 vertical ranks; petals 3–5 mm long
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Each photo represents one species in this genus.