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Key to Asteraceae, old Key J: Herbaceous composites with the leaves alternate or basal and the heads radiate, the rays white, pink, purple

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1 Receptacles chaffy (paleate).

2 Phyllaries dry, scarious-margined.

3 Ray florets 1-5 mm long; heads small in corymbiform arrays  Achillea

3 Ray florets > 5 mm long; heads large, terminating the branches  Anthemis

2 Phyllaries herbaceous, not scarious on margins.

4 Ray florets < 2.5 mm long; disk florets sterile, with an undivided style  Parthenium

4 Ray florets > 5 mm long; disk florets fertile, with a divided style.

5 Ray florets pink or light purple, > 15 mm long; heads single  Echinacea

5 Ray florets white, 5-10 mm long; heads 20-100 in a compound corymb  Verbesina

1 Receptacles naked (epaleate).

6 Pappus absent or coroniform.

7 Achene faces minutely glandular-glochidiate (bearing small gland-like bristles)  Astranthium

7 Achene faces glabrous or short-strigose but not glandular-glochidiate.

8 Leaves basal; cypselae marginally 2-ribbed; mature plants < 2 dm tall  Bellis perennis

8 Leaves cauline (and sometimes also basal); cypselae with ± 10 ribs; mature plants > 2 dm tall

9 Heads solitary or 2-3 in corymbiform arrays  Leucanthemum

9 Heads 5-60+ in corymbiform arrays  Tanacetum

6 Pappus present, of bristles or scales.

10 Heads primarily discoid with reduced ray florets  Hymenopappus

10 Heads radiate with conspicuous ray florets.

11 Taprooted annuals; ray florets 1-7 mm long.

12 Leaves and stems not fleshy, rarely glabrous; cypselas < 1.4 mm long  Erigeron

12 Leaves and stems fleshy, mostly glabrous; cypselas > 1.4 mm long  Symphyotrichum

11 Not taprooted and mostly perennials; ray florets > 3 mm long.

13 Ray florets usually > 60; blooming Apr-Oct  Erigeron

13 Ray florets usually < 60; blooming late May-Nov.

14 Receptacles hemispheric to conic; pappus often with 2-4 awns (Boltonia) or lacking awns and coroniform (Astranthium).

15 Achenes not narrowly winged, the surfaces minutely glandular-glochidiate (bearing small gland-like bristles)  Astranthium

15 Achenes narrowly winged, the surfaces sometimes puberulent but not glandular-glochidiate  Boltonia

14 Receptacles flat to slightly convex; pappus lacking awns.

16 At least the basal and lower leaves both petiolate and cordate/subcordate at base.

17 Often colonial; inflorescence corymbiform, flat-topped or rounded; outer phyllaries > 1 mm broad  Eurybia

17 Not colonial; inflorescence paniculiform, often elongate; outer phyllaries < 1 mm broad  Symphyotrichum

16 Basal and lower leaves not both petiolate and cordate/subcordate at base.

18 Leaves sessile and auriculate or cordate-clasping  Symphyotrichum

18 Leaves petiolate or epetiolate but not auriculate or cordate-clasping.

19 Cypselas glandular; pappus double  Oclemena

19 Cypselas not glandular; pappus single or double or in four series.

20 Leaves silvery-silky on both sides (at least when young), entire  Symphyotrichum

20 Leaves not silvery-silky, entire or toothed.

21 Pappus double, with inner bristles distinctly longer than outer bristles.

22 Leaves not rigid, veiny, lanceolate to elliptic or ovate, > 6 mm wide  Doellingeria

22 Leaves rigid, 1-nerved, linear to linear-spatulate, < 5 mm wide  Ionactis

21 Pappus simple with all bristles often about the same length.

23 Ray florets white, few (usually 3-8); cypselas densely silky  Sericocarpus

23 Ray florets white to pink or blue or purple, more numerous (usually 8-30); cypselas glabrous to pubescent but not densely silky.

24 Ray florets white; involucres < 6 mm long; phyllaries < 1 mm wide  Symphyotrichum

24 Ray florets white or pink to blue or purple; involucres 7-12 mm long; phyllaries usually > 1 mm wide.

Show caption*© Scott Ward                                                     25 Phyllaries glandular  Eurybia

25 Phyllaries not glandular.

26 Phyllaries long-attenuate or loose and spreading  Symphyotrichum

26 Phyllaries appressed, not long-attenuate.

27 Plants coarse-hairy; lowest leaves > 5 cm wide  Aster

27 Plants glabrous to hairy; lowest leaves < 3 cm wide  Eurybia