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Oligoneuron
See list of 2 species in this genusThe generic placement of species of Oligoneuron is controversial. Recent arguments to include these species within Solidago (e.g., Semple et al. 1999) are inconclusive given that the data used in the analyses were uniparentally inherited (cp DNA) and Oligoneuron is not nested within Solidago as stated by the authors—it was nested within Solidago only because they considered Oreochrysum parryi (Gray) Rydb. to be part of Solidago (see Nesom 2006d for rationale that Oreochrysum is distinct from Solidago).
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1a. Rays white, 5–9 mm long; lower leaf blades linear to narrow-oblanceolate, 2–10 mm wide; involucral bracts with a single, thickened midrib; many pappus bristles expanded at apex
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1b. Rays yellow, 3–5 mm long; lower leaf blades elliptic or elliptic-oblong to broad-lanceolate or broad-ovate, (15–)24–50(–100) mm wide; involucral bracts few-striate [Fig. 439]; pappus bristles slender at the apex
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Each photo represents one species in this genus.