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Key to Asteraceae, Key I: Herbaceous composites with the leaves alternate, the heads lacking rays, and with a pappus wholly or partly of scales or awns

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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  Hymenopappus

3 Pappus of 6-10 scales; [historical waif]  Hymenoxys anthemoides

2 Leaves unlobed, or if pinnately lobed, the segments broad (> 3 mm wide).

4 Receptacle paleate  Verbesina

4 Receptacle epaleate.

5 Pappus scales rudimentary, crown-like  Tanacetum

5 Pappus scales conspicuous.

6 Phyllaries 25-125 in 3-9 series; receptacles flat or slightly convex  Grindelia

6 Phyllaries 6-25 (-60) in 2-3 series; receptacles globose.

7 Stems not winged  Gaillardia

7 Stems winged from node to node  Helenium flexuosum

1 Disc flowers pink, purple, or white

8 Receptacle paleate  Marshallia

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]  Thurovia triflora

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  Elephantopus

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  Pseudelephantopus spicatus

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]  Hartwrightia floridana

13 Involucres 4-15+ mm in diameter; flowers 20-80 per head; [SC, GA, and FL westwards]  Hymenopappus

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  Centaurea

16 Pappus of an outer setiform scales (appearing as "flattened bristles"  Leuzea repens

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  Centaurea

17 Plant an annual; flowers pale to medium blue, flowering Apr-Jun  Cyanus depressus

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"  Stokesia laevis

18 Peripheral flowers of the heads similar to the interior flowers, all disc flowers.

19 Annuals; cypselas not ribbed  Cyanthillium cinereum

19 Perennials; cypselas 8-10-ribbed.

Show caption*© Jacek Pietruszewski, some rights reserved (CC BY), uploaded by Jacek Pietruszewski                                          20 Heads each subtended by 3-8 leafy bracts; pappus of narrow scales only, quickly falling  Centratherum punctatum

20 Heads not subtended by leafy bracts; pappus of an inner series of scales or bristles and an outer series of bristles, persistent  Vernonia