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Key to Grindelia

Asteraceae

Grindelia

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1 Pappus in 2 series, the outer of 25-40 barbellate bristles, the inner of 8-15+ setiform awns or subulate scales 7-10 mm long
1 Pappus in 1 series, of 2-3 (-8) setiform awns or subulate scales 2.5-8 mm long.
  2 Heads discoid, lacking rays.
    3 Stems decumbent to ascending (from rhizomes), dull green; plants perennial; flowering heads borne singly (rays always absent); plants 15-35 cm tall; [TX]
    3 Stems erect, whitish or stramineous; plants biennial, perennial or subshrubs; flowering heads in arrays, rarely borne singly (rays present or absent); plants usually 40-100 cm tall [widespread, including TX]
  2 Heads radiate, rays present.
      4 Plants annual; [of thickets, prairies, streams, various bottomlands; TX].
        5 Plants 30-130 cm tall; Leaves with 8-14 marginal teeth per cm; stems stramineous to purple; cypselae faces rugose (outer) or striate (inner); plants flowering mostly July-September
        5 Plants 15-40 cm tall; Leaves with 6-8 marginal teeth per cm; stems stramineous; cypselae faces smooth to slightly rugose; plants flowering mostly March-June
      4 Plants biennial or perennial (including subshrubs); [of limestone glades, rocky prairies, disturbed areas, various uplands; more widespread, including TX].
© Scott Ward
          6 Leaves 2-5x as long as wide; margins crenate to serrate; phyllaries squarrose-reflexed; pappi of 2-3 subulate scales (or setiform awns) shorter than disc corollas
          6 Leaves 3-12x as long as wide; margins serrate to dentate; phyllaries loose (but not squarrose); pappi of 2 straight, setiform awns equaling or slightly longer than disc corollas.
             7 Cauline leaves mostly lanceolate to linear; outer phyllaries more or less equal to outer phyllaries; [widespread, including OK and TX]
             7 Cauline leaves mostly ovate to oblong; outer phyllaries shorter than inner phyllaries; [OK, TX]