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3 Blades of lower leaves ovate to elliptic to oblanceolate, their bases truncate, abruptly tapering, or gradually tapering to petiole; lower leaves including petioles mostly less than 4× as long as wide (sometimes longer in S. brachyphylla with densely puberulent leaf surfaces and stems, and in S. arguta var. boottii and S. arguta var. caroliniana with blades sharply serrate and heads lacking phyllary-like bracts interior to ray florets); [subsection Argutae]. | |
5 Leaves scabrous on the upper surface. | |
6 Involucre (2.5-) avg. 3.9 (-6.5) mm high; basal and lower stem leaves 8-30 cm long, 4-10 cm wide, mostly 2-3× as long as wide; upper stem leaves few, somewhat reduced; disc florets averaging 11.8 per head; [Mountains, Interior Low Plateau, rarely Piedmont, and Coastal Plain only from DE northwards] | |
7 Leaves soft-villous; rays 7-12; flowering May-Jun; [Coastal Plain of e. NC and e. SC] | |
7 Leaves puberulent; rays 0 (-2); flowering Sep-Nov; [SC (NC?) south to FL and AL] | |
9 Plants with slender, stoloniferous rhizomes (in addition to the main, more deeply-seated rhizomes) | |
9 Plants lacking slender, stoloniferous rhizomes. | |
3 Blades of lower leaves oblanceolate to narrowly ovate, gradually tapering to petiole; lower leaves including petioles mostly more than 4× as long as wide (sometimes shorter in S. juncea with at least a few phyllary-like bracts interior to ray florets). | |
16 Stems obviously densely and loosely puberulent; [subsection Nemorales] | |
17 Pappus bristles usually exceeding the length of the ray floret corolla tubes; basal and lower stem leaves narrowly oblanceolate to nearly linear; leaf margins entire or with minute teeth only near the tip; disc corolla lobes (0.6-) 0.8-1.5 mm long; achenes moderately hairy; [mainly western in our region] | |
17 Pappus bristles usually not (or barely) exceeding the length of the ray floret corolla tubes; basal and lower stem leaves oblanceolate to narrowly obovate; leaf margins crenate-serrate through half or more of their length; disc corolla lobes 0.5-0.9 (-1.0) mm long; achenes sparsely hairy; [widespread in our region] | |
16 Stems glabrous or nearly so; [subsection Junceae]. | |
18 Rhizomes thin, elongated, creeping; stem leaves usually 3-nerved; [disjunct from west to glades and barrens] | |
19 Rays 3-7; disc florets 5-9 | |
21 Leaves somewhat fleshy, the stem leaves reduced but not very markedly so; inflorescence almost always with lower branches strongly recurved with secund heads; [usually of maritime or otherwise saline habitats, rarely in nontidal marshes or swamps]. | |
21 Leaves not fleshy (rarely so in S. stricta of near coastal situations), the stem leaves much reduced relative to the basal; inflorescence showing only relatively weak tendency to recurved branches with secund heads; [inland habitats, except rarely S. stricta]. | |
24 Basal leaves 0.7-2.5 cm wide; stem leaves linear or lanceolate (the lower cauline leaves 0.7-3 cm wide); disc flowers 9-15; [PA and WV (?) northwards] | |
24 Basal leaves 3-8 cm wide; stem leaves oblong-lanceolate (the lower cauline leaves 3-8 cm wide); disc flowers 4-8; [scattered in NC and TN; less sparsely distributed northwards] |