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Asteraceae Group 5
See list of 15 genera in this group-
1a. Anthers sagittate-tailed at the base; involucres with 3–7 series of involucral bracts
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2a. Leaf blades lanceolate or elliptic to ovate, 12–200 mm wide; involucres 8–20 mm in diameter; rays 15–40 mm long, conspicuously surpassing the involucres; body of cypsela not contracted just below the attachment of the pappus bristles; pappus bristles 6–10 mm long
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2b. Leaf blades linear to narrow-lanceolate, 1–3 (–10) mm wide; involucres 4–7 mm in diameter; rays 4–7 mm long, not or scarcely exceeding the involucres; body of the cypsela abruptly contracted just below the attachment of the pappus bristles; pappus bristles 3–4 (–5) mm long
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1b. Anthers cuneate to sagitate at the base, but not tailed; involucres with 1 or 2 series of involucral bracts or with 3–5 series in Chrysopsis, Euthamia, Heterotheca, Oligoneuron, Pityopsis, Solidago
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3a. Rays usually yellow with a white tip; receptacle with chaff; disk corollas puberulent
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3b. Rays entirely yellow; receptacle without chaff; disk flowers ± glabrous (sometimes sparsely pubescent in Heterotheca)
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4a. Middle stem leaves with a short, broadly winged petiole that prominently expands and clasps the stem; upper stem leaves cordate-clasping
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5a. Lower leaf blades broad-ovate to nearly orbicular, (5–) 7–14 cm wide; involucres 22–40 mm tall; pappus of disk flowers consisting of only bristles; plants perennial, from rhizomes
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5b. Lower leaf blades ovate to elliptic or lanceolate, 0.6–5.5 cm wide; involucres 4–8 (–10) mm tall; pappus of disk flowers consisting of both scales and bristles; plants annual or biennial, from taproots (in part)
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4b. Middle stem leaves sessile or petioled, but without an expanded, clasping petiole; upper stem leaves not cordate-clasping
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6a. Leaves opposite, except sometimes the upper; rays 15–20 mm long
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6b. Leaves alternate throughout the stem; rays shorter than 10 mm (except Chrysopsis with rays 10–20 mm long)
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7a. Stems with only small, bract-like leaves (i.e., scapose) [Fig. 475], appearing and flowering before the cordate-suborbicular blades of the basal leaves are produced; disk flowers sterile
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7b. Stems with leaves, these present during flowering [Fig. 444]; disk flowers fertile
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8a. Involucre composed of a single series of long bracts, sometimes also calyculate (i.e., with a short, outer series of bracts) [Fig. 449]
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9a. Plants perennial, with rhizomes and fibrous roots; leaves basally disposed (i.e., prominent clusters of basal leaves present, the stem leaves rapidly reduced in size upwards)
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9b. Plants annual or biennial (rarely short-lived perennial), mostly with evident taproots; leaves chiefly cauline (i.e., prominent clusters of basal leaves absent, the stem leaves gradually, if at all, reduced upwards)
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10a. Rays 4–8 mm long; leaf blades relatively more divided, usually 2- or 3-times pinnatifid; cypsela bodies from near margin of capitulum glabrous, the inner ones pubescent
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10b. Rays absent or up to 2 mm long [Fig. 449]; leaf blades relatively less divided, usually toothed to pinnatifid; usually all the cypsela bodies of the capitulum similar, either all pubescent or all glabrous in glandular-hairy S. viscosus (in part)
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11b. Capitulescence or its divisions flat-topped, resembling a corymb
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12a. Pappus monomorphic—composed of elongate and slender bristles
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13a. Leaves chiefly cauline, the blades linear to narrow-lanceolate, parallel-veined, resinous-punctate [Fig. 409]; involucral bracts with a single, median nerve; lower petiole bases not persistent
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13b. Leaves basally disposed, the blades elliptic or broad-lanceolate to broad-ovate, pinnately veined, not resinous-punctate; involucral bracts longitudinally few-striate [Fig. 439]; lower petiole bases often persistent (in part)
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12b. Pappus dimorphic—an inner series of elongate, slender bristles and an outer series of short, course bristles or narrow scales
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14a. Leaf blades linear, arcuate, parallel-veined, sessile, entire [Fig. 444]; cypsela body narrow-fusiform; involucre white-pubescent
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14b. Lower leaf blades lanceolate or oblanceolate to ovate, ± straight, pinnately veined, ± petiolate, toothed to entire; cypsela body obovoid to obconic; involucre stipitate-glandular
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15a. Pappus monomorphic, similar on both ray and disk flowers; cypselas monomorphic, all compressed; rays 8–11 ×2–3 mm; stems sericeous to sericeo-tomentose
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15b. Pappus dimorphic—absent on ray flowers and present on disk flowers; cypselas dimorphic, those of the ray flowers triangular in cross-section, those of the disk flowers compressed; rays 3–7 (–9) ×1–2 mm; stems hirsute to pilose (in part)
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Each photo represents one genus in this subgroup.