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Key to Asteraceae

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Show caption*© Alan Cressler: Ampelaster carolinianus, Juniper Creek, Juniper Prairie Wilderness, Ocala National Forest, Marion County, Florida 4 by Alan Cressler 1 Plant a shrub or liana (woody vine), definitely with woody growth well above ground level  Key to Asteraceae, Key A: woody composites (shrubs and lianas)

Show caption*© Scott Ward 1 Plant an annual, biennial, or perennial, lacking woody growth above ground level (or suffrutescent at the base).

Show caption*© Keith Bradley   2 Leaves opposite or whorled, at least on the lower stem nodes (the leaves higher on the stem sometimes alternate).

Show caption*© Keith Bradley     3 Heads discoid or disciform, with disk florets only  Key to Asteraceae, Key B: herbaceous composites with opposite or whorled leaves and discoid or disciform heads (lacking ray florets)

Show caption*© Richard & Teresa Ware     3 Heads radiate, with both ray and disk florets present.  Key to Asteraceae, Key C: herbaceous composites with opposite leaves and radiate heads

Show caption*© Jay Horn   2 Leaves either alternate (not opposite even at lower nodes of the stem) or basal only (the heads on scapiform stems).

Show caption*© Scott Ward       4 Heads borne solitary on scapes, or many in a raceme on stems with only scale-like bracts  Key to Asteraceae, Key D: Herbaceous composites with the leaves basal only (stems bearing heads with bracts only)

Show caption*© Keith Bradley       4 Heads borne on stems with leaves, the leaves alternate, opposite, or whorled on the stem, and sometimes also well developed basal leaves or rosettes.

Show caption*© Alan M. Cressler         5 Heads liguliflorous (composed of ligulate florets); sap usually milky  Key to Asteraceae, Key E: herbaceous composites with leaves alternate or basal, liguliflorous heads (composed of ligulate florets), and sap usually milky

5 Heads discoid, disciform, radiant, or radiate (not only composed of ligulate florets); sap usually clear.

6 Heads discoid or disciform (composed primarily of disc florets and peripheral filiform florets), OR heads radiant, essentially composed of ordinary disc florets and dilated periphereal florets (these peripheral florets dilated, perfect, pistllate, or netural, but lacking broadly expanded laminae of ordinary ray florets).

Show caption*© Gary P. Fleming              7 Leaves spiny-margined, phyllaries usually spine-tipped; disk flowers pink (rarely blue or yellow)  Key to Asteraceae, Key F: herbaceous composites with leaves spiny, leaves alternate or basal, and heads discoid

7 Leaves not spiny-margined; phyllaries spine-tipped or not; disk flowers variously colored (including pink)

8 Pappus none or rudimentary [look at summit of achenes or ovary]  Key to Asteraceae, Key G: Herbaceous composites with the leaves alternate, the heads lacking rays, and with 0 pappus

8 Pappus well-developed, of bristles, awns, scales, or a combination of these.

9 Pappus of bristles only (the bristles smooth, barbellulate, barbellate, or plumose)  Key to Asteraceae, Key H: Herbaceous composites with the leaves alternate, the heads lacking rays, and with a pappus of bristles only

9 Pappus wholly or partially of scales (broad to narrow, sometimes almost bristle-like, but at least in part flattened) or awns (these often barbed)  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

6 Heads radiate, with both central disc and peripheral ray florets, the ray florets with prominent laminae.

10 Rays yellow, cream, orange, or rarely red-tinged.

11 Receptacles paleate (with chaff) [best seen by removing flowers or achenes from the receptacle]  Key to Asteraceae, Key J: Herbaceous composites with the leaves alternate or basal and the heads radiate, the rays yellow, orange, red

11 Receptacles naked (epaleate), rarely with imbedded bristles (or Gaillardia sometimes with short setae 1-6 mm long but these much shorter than the pappus scales of the cypselae)  Key to Asteraceae, Key K: Herbaceous composites with the leaves alternate or basal and the heads radiate, the rays yellow, orange, red

10 Rays white, pink, purple, or bluish.

12 Pappus none or rudimentary [look at summit of achenes or ovary]  Key to Asteraceae, Key L: Herbaceous composites with the leaves alternate or basal and the heads radiate, the rays white, pink, purple, and the 0 pappus

12 Pappus well-developed, of bristles, awns, scales, or a combination of these.

13 Pappus of bristles only (the bristles smooth, barbellulate, barbellate, or plumose)  Key to Asteraceae, Key M: Herbaceous composites with the leaves alternate or basal and the heads radiate, the rays white, pink, purple, and with a pappus of bristles only

13 Pappus wholly or partially of scales (broad to narrow, sometimes almost bristle-like, but at least in part flattened) or awns (these often barbed)  Key to Asteraceae, Key N: Herbaceous composites with the leaves alternate or basal and the heads radiate, the rays white, pink, purple, and the pappus absent or essentially so