Senecio integerrimus

           Entire-Leaved Groundsel

Flower Head, Longitudinal Section

Centre Block, Cypress Hills Interprovincial Park
15-June-2008

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Integerrimus: Answers to key questions in Budd's Flora (BF)  and Flora of Alberta (FOA) leading to this species. 
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NOT [plants annual, of marshy or aquatic habitats, densely villous throughout, tips of the involucral bracts not bearded or black] (FOA)

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perennial plants, usually with rootstocks; NOT [annual plants with taproots]

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plants with an abruptly shortened, button-like caudex; NOT [plants rhizomatous] (FOA)

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plants pubescent, sometimes sparsely; NOT [plants glabrous (at least by flowering) (FOA)

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leaves all or mostly subentire to dentate; NOT [leaves all or mostly coarsely lobed to pinnately divided] (BF)

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leaves denticulate to entire; NOT [leaves irregularly toothed] (FOA)

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stem leaves different from basal leaves; NOT [stem leaves and basal leaves equal in size and shape] (BF)

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lower leaves usually distinctly petiolate; NOT [lower leaves not distinctly petiolate] (FOA)

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lower leaves mostly lanceolate to ovate or suborbicular; NOT [lower leaves mostly linear to lanceolate] (FOA)

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middle and upper stem leaves much reduced in size, largest at base; NOT [middle and upper stem leaves as large as or slightly smaller than lower leaves] (BF), NOT [stem leaves not reduced in size upwards, largest leaves often about the middle] (FOA)

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inflorescence mostly terminal; NOT [inflorescence mostly axillary] (BF)

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flower heads few to many; NOT [flower heads solitary] (BF),  NOT [with a small head at base] (BF)

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axillary peduncles short; NOT [axillary peduncles long] (BF)

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involucral bracts black-tipped, sometimes only the outer; NOT [involucral bracts not black-tipped] (FOA)

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heads with rays; NOT [heads rayless or rays minute, the heads appearing rayless] (FOA)

 

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Senecio: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.
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juice watery; NOT [juice milky] (FOA)

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leaves alternate or basal; NOT [leaves opposite] (FOA)

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involucral bracts uniseriate, equal, narrow, commonly with a few much shorter outer ones at the base; NOT [involucral bracts either imbricate in several series, or broad and somewhat leafy, or both] (FOA)

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involucral bracts not or scarcely imbricated; NOT [involucral bracts well imbricated] (BF)

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receptacle naked (FOA)

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flower heads with florets both tubular and ray (radiate) (BF)

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ligulate flowers pistillate or neuter; NOT [flowers all perfect] (FOA)

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rays yellow; NOT [rays white, to pink, purple or blue] (FOA)

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stamens united to form a tube around the pistil (BF)

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pappus single, bristles sometimes unequal but not distinctly divided into an inner and outer series of two lengths; NOT [pappus double, bristles of the outer series inconspicuous, distinctly shorter than the inner] (FOA)

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pappus wholly or partly of capillary bristles, sometimes plumose; NOT [pappus chaffy, or of scales, or of firm awns, or a crown or none] (FOA)