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1 Basal and lower stem leaves petiolate with a cordate or subcordate blade and/or a cordate-clasping petiole; [subsection Argutae]. |
..2 Pappus > ½× as long as the disc corollas; rays 1-3 |
..2 Pappus < ¼× as long as the disc corollas; rays 3-6 |
1 Basal and lower stem leaves with cuneate leaf blades and petioles not cordate-clasping (though leaves may have petioles which sheath the stem). |
....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]. |
......4 Leaves either definitely scabrous or moderately to densely soft-villous or puberulent. |
........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] |
..........6 Involucre (3.5-) avg. 6.1 (-8.8) mm high; basal and lower stem leaves 6-24 cm long, 2-6 cm wide, mostly 3-5× as long as wide; upper stem leaves many, strongly reduced; disc florets averaging 9.3 per head; [Coastal Plain and very rarely lower Piedmont and AL Mountains] |
........5 Leaves moderately to densely soft-villous or puberulent. |
............ 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] |
............ ..8 Inner phyllaries linear; leaves green (not glaucous) |
............ ..8 Inner phyllaries oblong; leaves glaucous |
......4 Leaves either glabrous (or nearly so) or strigose or strigillose. |
............ ....9 Plants with slender, stoloniferous rhizomes (in addition to the main, more deeply-seated rhizomes) |
............ ......10 Upper stem leaves quickly reduced in size compared to the lower, ascending or appressed; basal and lower stem leaves elliptic to obovate (rarely ovate), acute or obtuse, with narrowly attenuate bases; [LA, TX, AR, and OK] |
............ ......10 Upper stem leaves gradually reduced in size, ascending to spreading; basal and lower stem leaves mostly ovate, acute to acuminate, with truncate to obtuse bases; [NJ south to AL] |
............ ....9 Plants lacking slender, stoloniferous rhizomes. |
............ ........11 Phyllaries striate, with several nerves prominent; involucres 4.5-6 (-7) mm high |
............ ........11 Phyllaries not striate, only the midvein prominent; involucres 2.5-5.6 mm high. |
............ ..........12 Basal leaves truncate at the base; leaves thick in texture |
............ ..........12 Basal leaves cuneate to rounded at the base; leaves of normal herbaceous texture. |
............ ............ 13 Achenes glabrous |
............ ............ 13 Achenes strigillose, at least toward the apex. |
............ ............ ..14 Leaves strigose or strigillose |
............ ............ ..14 Leaves glabrous |
....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). |
............ ............ ....15 Petiole bases of basal and lower stem leaves not sheathing the stem; [of mesic or dry habitats]. |
............ ............ ......16 Stems obviously densely and loosely puberulent; [subsection Nemorales] |
............ ............ ........17 Basal and lower stem leaves narrowly oblanceolate to nearly linear; leaf margins entire or with minute teeth near the tip; achenes moderately hairy; [mainly western in our region] |
............ ............ ........17 Basal and lower stem leaves oblanceolate to narrowly obovate; leaf margins crenate-serrate through half or more of their length; 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] |
............ ............ ..........18 Rhizomes thick, short; stem leaves not 3-nerved; [collectively of various habitats]. |
............ ............ ............ 19 Rays 7-13; disc florets 8-12 |
............ ............ ............ 19 Rays 3-7; disc florets 5-9 |
............ ............ ............ ..20 Upper stem leaves ascending to appressed, usually lacking axillary fascicles; [west of the Blue Ridge] |
............ ............ ............ ..20 Upper stem leaves spreading or reflexed, with axillary fascicles of reduced leaves; [east of the Blue Ridge] |
............ ............ ....15 Petiole bases of basal and lower stem leaves sheathing the stem; [seasonally saturated habitats]; [subsection Maritimae]. |
............ ............ ............ ....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]. |
............ ............ ............ ......22 Involucres 3-4 mm high; rays 7-11; disc flowers ca. 10-16; leaves ciliolate; larger leaves < 3 cm wide; [MA south to FL, west to TX and beyond] |
............ ............ ............ ......22 Involucres 4-7 mm high; rays 12-17; disc flowers ca. 17-22; leaves not ciliolate; larger leaves > 3 cm wide; [VA northward] |
............ ............ ............ ....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]. |
............ ............ ............ ........23 Basal leaves 0.7-8 cm wide; plants short, 4-10 (-15) dm tall, typically fairly stout; [mainly of the Mountains (and the Coastal Plain from e. VA northwards), e. VA, w. NC, nw. SC, ne. GA, and northward]. |
............ ............ ............ ..........24 Ray flowers averaging 3; disc flowers averaging 8; heads 6-7 mm tall; [seepage over sloping rock on granitic domes, of sw. NC, nw. SC, and ne. GA] |
............ ............ ............ ..........24 Ray flowers averaging 5; disc flowers averaging 6; heads 4-5 mm tall; [peaty bogs and fens, w. NC and e. TN northward]. |
............ ............ ............ ............ 25 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] |
............ ............ ............ ............ 25 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] |
............ ............ ............ ........23 Basal leaves 0.2-2.5 (-5) cm wide; plants short to tall, 3-20 dm tall, typically very slender; [Coastal Plain and lower Piedmont and southward]. |
............ ............ ............ ............ ..26 Basal leaves 0.2-0.5 (-0.7) cm wide; [s. peninsular FL] |
............ ............ ............ ............ ..26 Basal leaves 0.7-2.5 (-5) cm wide; [collectively more widespread]. |
............ ............ ............ ............ ....27 Leaf margins smooth, entire; ray flowers 8-13 per head; disk flowers 14-25 per head; pappus (2.5-) 3.0-3.5 mm long; plants to 1 m tall |
............ ............ ............ ............ ....27 Leaf margins (of the basal leaves at least) scabrous-margined and/or serrate; ray flowers 2-7 per head; disk flowers 6-16 per head; pappus 2.2-4.5 (-5.0) mm long; plants to 2 m tall. |
............ ............ ............ ............ ......28 Leaf margins (of the basal leaves at least) serrate and also scabrous. |
............ ............ ............ ............ ........29 Lower branches of inflorescence long, spreading, curved |
............ ............ ............ ............ ........29 Lower branches of inflorescence long, divergent in larger specimens |
............ ............ ............ ............ ......28 Leaf margins (of the basal leaves at least) merely scabrous or smooth. |
............ ............ ............ ............ ..........30 Leaf margins scabrous (or at least tuberculate) throughout; panicle branches often spreading-erect with recurved-secund tips; pappus 2.2-4.0 mm long |
............ ............ ............ ............ ..........30 Leaf margins tending to become smooth on leaves of the upper stem; panicle branches usually stiffly erect; pappus 4.0-4.5 (-5.0) mm long |