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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 |
1 Leaves with only the midvein readily apparent; leaves entire; leaf surfaces finely translucent punctate (most obviously seen with transmitted light or with 10× magnification); fresh leaves usually anise-scented; [subgenus Triactis, section Odorae]. |
..2 Main leaves ovate to lanceolate, 2-5 (-6)× as long as wide; stem pubescence general and circumferential; [of FL] |
..2 Main leaves lanceolate to linear, (4-) 5-15× as long as wide; stem pubescence in lines decurrent down the stem from the margins of the leaf bases; [widespread] |
1 Leaves either triple-veined or pinnately-veined; leaves entire or often at least obscurely toothed; leaf surfaces not translucent punctate; fresh leaves not anise-scented. |
....3 Leaves pinnately veined; leaves mostly 3-5× as long as wide. |
......4 Leaf venation not notably reticulate; plants to 12 dm tall, from a compact caudex; [subgenus Pleiactila, section Venosae, subsection Ulmifoliae]. |
........5 Leaves glabrous |
........5 Leaves sparsely hirsute below, at least on the midvein and larger lateral veins |
......4 Leaves pinnately veined and also forming a prominent reticulum, the veins (primary, secondary, and tertiary) very evidently raised on the undersurface (less obviously so in S. fistulosa); plants to 30 (-40) dm tall, from long-creeping rhizomes, thus forming clonal patches; [subgenus Pleiactila, section Venosae, subsection Venosae]. |
..........6 Mid-stem leaves sessile, somewhat clasping; leaf margins nearly entire to obscurely serrulate; leaves planar |
..........6 Mid-stem leaves subsessile, not clasping; leaf margins strongly serrate; leaves rugose. |
............ 7 Involucres 4-6 mm high; broader phyllaries 0.7-1.2 mm wide; stems glabrous below the inflorescence; mid-stem leaves elliptic (widest near the middle) |
............ 7 Involucres (2-) 2.5-3.5 (4.5) mm high; phyllaries mostly < 0.5 mm wide; stems hairy or glabrous below the inflorescence; mid-stem leaves lanceolate to ovate (widest below the middle). |
............ ..8 Leaves relatively thin, not very rugose, usually sharply serrate, the apices acuminate, glabrous or soft-hairy on the surfaces; rays (4-) 5-12 (-13). |
............ ....9 Stem glabrous throughout (except for scattered hairs in inflorescence), stem with striate ridges decurrent from leaf bases; leaf blades appressed serrate (teeth short), blades glabrous beneath except for sparse, short, appressed, straight hairs; early blooming (1 month earlier than S. rugosa in same area); [permanently saturated, ± forested wetlands with Sphagnum moss, such as red maple-Atlantic white cedar swamps, streamhead pocosins, montane bogs] |
............ ....9 Stem pubescent with crinkly hairs throughout (occasional plants varying to glabrate below), stem without striate ridges decurrent from leaf bases; leaf blades sharply serrate (teeth coarse), blades villous to crinkly hairy beneath; late blooming (ca. 1 month later than S. aestivalis in same area); [dry to moist fields, meadows, and other open habitats] |
............ ..8 Leaves relatively thick and firm, strongly rugose, usually subentire to bluntly serrate, the apices often only acute, slightly to strongly scabrous or stiffly-hairy on the surfaces; rays 4-9. |
............ ......10 Inflorescences narrow, the lower lateral branches only slightly exceeding the subtending leaves; leaves sparsely pubescent; [of the Southern Appalachians] |
............ ......10 Inflorescences broad, the lower lateral branches generally much longer than the subtending leaves; leaves moderately to densely pubescent; [collectively widespread]. |
............ ........11 Upper stem leaves lanceolate to elliptic, not much reduced relative to leaves lower on the stem |
............ ........11 Upper stem leaves ovate, much reduced relative to leaves lower on the stem |
....3 Leaves triple-veined (two side veins arising near the base of the leaf and arching first away and then back towards the midvein); leaves 2-20× as long as wide. |
............ ..........12 Upper stem (above the midpoint, up to the branches of the inflorescence) glabrous. |
............ ............ 13 Plants to 20 dm tall; basal leaves never present; mid-stem leaves averaging 4-6× as long as wide; upper stem usually slightly to moderately glaucous as well as glabrous; [widespread]; [subgenus Pleiactilis, section Unilaterales, subsection Serotinae] |
............ ............ 13 Plants to 10 dm tall; basal leaves withering or not before flowering (if not, also keyed elsewhere), often with assocated sterile offshoots with basal leaves; mid-stem leaves averaging 5-10× as long as wide; upper stem glabrous, green; [KY, TN, and MS westwards]. |
............ ............ ..14 Rootstock short and branched, not producing creeping rhizomes; ray flowers 5-8; receptacle lacking intercalated green bracts (resembling phyllaries) inward from the rays; mid and upper stem leaves usually lacking axillary fascicles of smaller leaves; [subgenus Pleiactilis, section Unilaterales, subsection Radulae] |
............ ............ ..14 Rootstock producing creeping rhizomes; ray flowers 7-13; receptacle often with a few intercalated green bracts (resembling phyllaries) inward from the rays; mid and upper stem leaves usually with axillary fascicles of smaller leaves; [subgenus Pleiactilis, section Unilaterales, subsection Junceae] |
............ ..........12 Upper stem hairy (above the midpoint, up to the branches of the inflorescence), variously puberulent, strigillose to strigose, villous, or scabrous. |
............ ............ ....15 Midstem leaf blades 1-4 (-5)× as long as wide, the base attenuated to a winged petiole (at least in leaves of the lower midstem(; plants 1-10 dm tall; [collectively in IL, MO, AR, and LA westwards, disjunct eastwards in KY, NC, SC, GA, and AL] |
............ ............ ......16 Leaf margins coarsely serrate; midstem leaf blades mostly 1.3-2× as long as wide; leaf surfaces evenly short villous; [IL & MO south to AR]; [subgenus Pleiactilis, section Venosae, subsection Drummondiani] |
............ ............ ......16 Leaf margins entire to finely serrate; midstem leaf blades mostly 2-4 (-5)× as long as wide; leaf surface vestiture appressed to scabrous; [subgenus Pleiactilis, section Unilaterales, subsection Radulae]. |
............ ............ ........17 Leaf surfaces with appressed (strigillose) hairs; upper stem vestiture densely strigose, the stems appearing grayish-green; rhizomes long-creeping, the plants forming clonal patches; [OK and nc. TX westwards and northwestwards] |
............ ............ ........17 Leaf surfaces scabrous; upper stem vestiture scabrous to loosely puberulent, the stems appearing green or dingy green; rhizomes short (less commonly moderately creeping); [se. KS, OK, and TX eastwards] |
............ ............ ....15 Midstem leaf blades 4-20× as long as wide, the base sessile and cuneate to rounded; plants 3-20 dm tall; [collectively widespread]. |
............ ............ ..........18 Rays 2-8; midstem leaves 4-15 mm wide, mostly 6-20× as long as wide, either twisted at base or not. |
............ ............ ............ 19 Larger mid-stem leaves lanceolate to narrowly elliptic, 7-10 cm long, 10-15 mm wide; leaves not twisted; [KY and s. IN]; [subgenus Pleiactilis, section Unilaterales, subsection Canadensae] |
............ ............ ............ 19 Larger mid-stem leaves linear to lance-linear, 2-9 cm wide, 2-7 (-10) mm wide; leaves either twisted at base or not; [either OK and westwards, or Coastal Plain from VA to FL west to TX and AR]. |
............ ............ ............ ..20 Leaves 4-9 cm long, 4-5 mm wide; [inland provinces, OK and westwards]; [subgenus Pleiactilis, section Unilaterales, subsection Radulae] |
............ ............ ............ ..20 Leaves 2-7 cm long, 2-7 (-10) mm wide; [Coastal Plain, VA to FL west to TX and AR]; [subgenus Pleiactilis, section Unilaterales, subsection Tortifoliae] |
............ ............ ..........18 Rays 4-17 (-24); midstem leaves 5-30 mm wide, 4-12× as long as wide, not twisted at base. |
............ ............ ............ ....21 Midstem leaves mostly 8-12× as long as wide. |
............ ............ ............ ......22 Rays 10-15; [wet pine savanna and marsh habitats, Coastal Plain of NC, SC, GA, FL, AL, and MS]; [subgenus Pleiactilis, section Unilaterales, subsection Tortifoliae] |
............ ............ ............ ......22 Rays 7-11; [riverscour habitats, inland provinces of PA, MD, DC, VA, WV, IN, KY, TN]; [subgenus Pleiactilis, section Unilaterales, subsection Canadensae] |
............ ............ ............ ....21 Midstem leaves mostly 4-6× as long as wide; [subgenus Pleiactilis, section Unilaterales, subsection Canadensae]. |
............ ............ ............ ........23 Mid-stem leaves serrate, the teeth 3-8 (-10) per side, the largest > 1.5 mm long; involucres 1.7-2.5 (-3.0) mm high. |
............ ............ ............ ..........24 Lower to mid-stem glabrous or sparsely pubescent |
............ ............ ............ ..........24 Lower to mid-stem moderately pubescent |
............ ............ ............ ........23 Mid-stem leaves entire to serrulate, the teeth usually 0-6 per side (up to 14); involucres (2.5-) 3-4.5 mm high. |
............ ............ ............ ............ 25 Upper surface of the leaves moderately to densely pubescent with short, curved to spreading hairs; [western] |
............ ............ ............ ............ 25 Upper surface of the leaves sparsely to moderately roughened with minute bulbous-based hairs (stouter and shorter than the hairs on the lower surface), or glabrous except along the veins. |
............ ............ ............ ............ ..26 Inflorescence broad; upper stem leaves not reduced in size relative to the mid-stem leaves; [broadly eastern] |
............ ............ ............ ............ ..26 Inflorescence elongated, narrow; upper stem leaves reduced; [southern] |