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1 Stem leaves very numerous, 0.5-2 (-4) mm wide, not decurrent on the stem or branches; taprooted annuals. |
..2 Disc corollas yellow, the lobes yellow or yellow-brown; lower and basal leaves usually withered at anthesis; lower leaves usually entire (rarely toothed); basal leaves entire to toothed (rarely pinnatifid) |
..2 Disc corollas yellow, the lobes (and sometimes also the upper portion of the corolla tube) purple; lower and basal leaves often persistent; lower leaves linear to ovate, entire, toothed, lobed or pinnatifid; basal leaves pinnatifid |
1 Stem leaves few to numerous, at least the larger > 4 mm wide, decurrent on the stems and branches; fibrous-rooted perennials or taprooted annuals/biennials. |
....3 Ray flowers absent; disc flowers with lobes (at least) brown, red, or purple |
....3 Ray flowers present; disc flowers either yellow or with lobes (at least) brown, red, or purple. |
......4 Ray flowers bearing a pistil and style, fertile. |
........5 Plants fibrous-rooted perennials; [section Helenium]. |
..........6 Leaves not basally disposed, the basal leaves usually absent at flowering (if present, mostly < 2 cm long), the stem leaves not progressively reduced upward; pappus scales brownish, 0.3-1.2 mm long (usually < 1 mm long); upper cauline leaves serrate (rarely entire), mostly oblanceolate, usually broadest near the midpoint or beyond it, with conspicuous lateral veins apparent on the lower surface |
..........6 Leaves basally disposed, the basal rosette usually present at flowering, the basal leaves > 4 cm long, larger than the progressively smaller stem leaves; pappus scales white-hyaline, 0.9-1.9 mm long (usually > 1 mm long); upper cauline leaves entire, lanceolate, usually broadest at or near the base and rather evenly tapered to the apex, lacking conspicuous lateral veins |
........5 Plants tap-rooted annuals or biennials; [section Tetrodus]. |
............ 7 Involucres 6-11 (-14) mm high, 6-11 (-13) wide (excluding the ray flowers); disk corollas 4- or 5- lobed. |
............ ..8 Disc corollas 5-lobed; ray flowers 8-9, yellow or partially/wholly red; [TX] |
............ ..8 Disc corollas 4-lobed; ray flowers 10-15, yellow; [widely distributed] |
............ 7 Involucres 4-8 mm high, 4-8 mm wide (excluding the ray flowers); disc corollas 5-lobed. |
............ ....9 Upper leaves entire; pappus scales 0.05-0.2 mm long |
............ ....9 Upper leaves serrate; pappus scales (0.2-) 0.3-0.4 (-0.5) mm long |
......4 Ray flowers lacking a pistil and style, sterile; [section Leptopoda]. |
............ ......10 Disc flowers with lobes (at least) brown, red, or purple. |
............ ........11 Disc flowers predominately 4-lobed and with 4 stamens; heads 5-50 (-80) per plant; pappus scales aristate |
............ ........11 Disc flowers 5-lobed and with 5 stamens; heads 1-20 per plant; pappus scales acute. |
............ ..........12 Heads 1-5 (-10) per plant; pappus scales 1.0-1.7 mm long; basal leaves and lower stem glabrous to sparsely hairy; [VA west and south to ne. TN, s. MS, and e. LA] |
............ ..........12 Heads 3-20 per plant; pappus scales 0.3-0.5 mm long; basal leaves and lower stem moderately to densely hairy; [AR and n. LA] |
............ ......10 Disc flowers with lobes yellow. |
............ ............ 13 Pappus scales deeply lacerate |
............ ............ 13 Pappus scales entire or slightly lacerate. |
............ ............ ..14 Midstem leaves barely decurrent on the stem, the decurrency < 0.5 cm; basal leaves often pinnatifid (less commonly merely dentate, repand, or entire), the lower portion of the leaf not contracted so as to be petiolate in form; achene pubescent on the ribs; peduncle pubescent; basal leaves (3.0-) 4.5-8.0 (-19.0) cm long, 0.3-1.1 cm wide, averaging ca. 7-10× as long as wide |
............ ............ ..14 Midstem leaves decurrent on the stem, the decurrency > 2 cm , and usually extending to the next leaf down; basal leaves usually repand or entire (rarely somewhat lobed or pinnatifid), the lower portion narrowed into a petiolate form which enlarges at its base to more-or-less clasp the stem; achene glabrous, or pubescent on the ribs; peduncle pubescent or glabrous; basal leaves averaging narrower or broader in shape (see below). |
............ ............ ....15 Peduncle pubescent to tomentose or lanose between the uppermost leaf and the head; achene pubescent on the ribs; heads 1-4 per plant; basal leaves (2.5-) 4.0-10.5 (-18.0) cm long, (0.8-) 1.2-2.0 (-2.5) cm wide, averaging ca. 4-6× as long as wide |
............ ............ ....15 Peduncle glabrous or glabrate between the uppermost leaf and the head; achene glabrous; heads 1 per plant; basal leaves (3.0-) 6.5-17.0 (-25.0) cm long, (0.4-) 0.6-1.0 (-1.5) cm wide, averaging ca. 10-15× as long as wide |
1 Disc flowers yellow, orange, red, or brownish. |
..2 Leaves 1-2× pinnately lobed into linear or filiform segments. |
....3 Pappus of 16-20 scales |
....3 Pappus of 6-10 scales; [historical waif] |
..2 Leaves unlobed, or if pinnately lobed, the segments broad (> 3 mm wide). |
......4 Receptacle paleate |
......4 Receptacle epaleate. |
........5 Pappus scales rudimentary, crown-like |
........5 Pappus scales conspicuous. |
..........6 Phyllaries 25-125 in 3-9 series; receptacles flat or slightly convex |
..........6 Phyllaries 6-25 (-60) in 2-3 series; receptacles globose. |
............ 7 Stems not winged |
............ 7 Stems winged from node to node |
1 Disc flowers pink, purple, or white |
............ ..8 Receptacle paleate |
............ ..8 Receptacle epaleate. |
............ ....9 Disc flowers 1-5 (rarely more) per head. |
............ ......10 Disc flowers white (rarely cream), 3; heads not aggregated into a secondary cluster subtended by bracts; [se. TX] |
............ ......10 Disc flowers lavender to purple, sometimes so lightly so as to be white, 1-4 (-5+); heads aggregated into clusters of 1-40 heads, subtended by 1-3 bracts; [collectively widespread in our region] |
............ ........11 Heads (1-) 10-40 per secondary cluster, borne in corymbiform arrays; bracts subtending clusters (2-) 3, deltate; pappus of 5 (-6) scales, each aristate |
............ ........11 Heads 1-5+ per secondary cluster, borne in spiciform arrays; bracts subtending clusters 1-2, linear, lanceolate, or spatulate; pappus of 6-10 scales, laciniate or aristate |
............ ....9 Disc flowers (2-) 10-100+ per head (at least most heads with >10 flowers). |
............ ..........12 Phyllaries 5-15 (-21) in 1-2 (-3) series. |
............ ............ 13 Involucres 2-3 mm in diameter; flowers 7-10 per head; [Coastal Plain, FL and GA] |
............ ............ 13 Involucres 4-15+ mm in diameter; flowers 20-80 per head; [SC, GA, and FL westwards] |
............ ..........12 Phyllaries 18-many in 5+ series. |
............ ............ ..14 Phyllary tips modified into a spine or into an enlarged, lacerate or pectinate network or fringe; receptacle epaleate, but densely bristly; [tribe Cynareae]. |
............ ............ ....15 Heads discoid, all flowers similar |
............ ............ ......16 Pappus normally of plumose bristles (and keyed elsewhere), but sometimes reduced to scales or awns |
............ ............ ......16 Pappus of an outer setiform scales (appearing as "flattened bristles" |
............ ............ ....15 Heads disciform or radiant, the outer flowers of the head sterile, with long lobes, appearing like false rays |
............ ............ ........17 Plant a perennial; flowers pink to purple, flowering Jun-Oct |
............ ............ ........17 Plant an annual; flowers pale to medium blue, flowering Apr-Jun |
............ ............ ..14 Phyllary tips not so modified, unarmed and unelaborate; receptacle epaleate and naked; [tribe Vernonieae]. |
............ ............ ..........18 Peripheral flowers of the heads enlarged and bilaterally symmetrical, appearing like "false rays" |
............ ............ ..........18 Peripheral flowers of the heads similar to the interior flowers, all disc flowers. |
............ ............ ............ 19 Annuals; cypselas not ribbed |
............ ............ ............ 19 Perennials; cypselas 8-10-ribbed. |
............ ............ ............ ..20 Heads each subtended by 3-8 leafy bracts; pappus of narrow scales only, quickly falling |
............ ............ ............ ..20 Heads not subtended by leafy bracts; pappus of an inner series of scales or bristles and an outer series of bristles, persistent |