Tribe 7. ANTHEMIDEAE - chamomile tribe
(Source: Mickelson and Iltis, 1966; Fernald, 1950; Gleason and Cronquist, 1991;
1. Receptacle chaffy; heads radiate.
2. Heads small, 5 mm or less in diameter, densely corymbose; receptacle flat; achenes compressed
......... ACHILLEA - yarrow.
2. Heads rather large, 1‑4 cm in diameter, solitary and terminal on long peduncles; receptacle conic at maturity; achenes terete or angled.
3. Ray florets white; disk 0.5‑1.2 cm in diameter .
.... ANTHEMIS - chamomile, dog-fennel.
3. Ray florets yellow; disk 1‑2 cm in diameter; rare adventive .
.... COTA - marguerite.
1. Receptacle naked or villous; heads radiate, disciform or discoid.
4. Inflorescence paniculate, racemose or spike-like with inconspicuous (2‑8 mm long) disciform or discoid heads; florets green
......... ARTEMISIA - wormwood.
4. Inflorescence corymbose OR heads terminal on long peduncles; ray florets showy, yellow or white (sometimes obsolete).
5. Receptacle conic at maturity; leaves pinnatisect
.... MATRICARIA & TRIPLEUROSPERMUM - wild chamomile.
5. Receptacle flat or low-convex.
6. Heads several or numerous, in corymbs, disk 4-9 mm wide, with or without rays; leaves often highly lobed
........ TANACETUM - tansy.
6. Heads solitary at tips of stem or long branches, large, disk 1-2.5 cm wide, with conspicuous white rays; leaves toothed to lobed.
7. Heads solitary on long, slender, naked peduncles; upper leaves strongly reduced or lacking; stems slender, 4‑6 dm tall; abundant throughout
7. Heads few to many at end of robust, leafy, 1‑2 m tall stems; peduncles 3‑15 cm long; rare garden escape
ACHILLEA - yarrow
(s = 9)
1. Leaves undissected, serrulate; plant glabrate to subglabrous; rare adventive (s = 2x) .
........... A. Ptarmica - sneezeweed.
1. Leaves finely dissected into linear segments; plant tomentose; ubiquitous throughout (s = 2x, 3x, 4x, 5x, 6x, 7x, 8x)
.... A. Millefolium - common yarrow, milfoil.
2. Leaves flat, the relatively broad ultimate segments all nearly in the same plane; hexaploid; less common introduced taxon (mostly s = 6x)
......... subsp. Millefolium.
2. Leaves airily 3‑dimensional, the ultimate segments narrower and disposed in various planes; tetraploid; very common native taxon (mostly s = 4x)
......... subsp. lanulosa.
ANTHEMIS - chamomile, dog-fennel
(s = 2x; x = 9)
1. Ray florets sterile; receptacle chaffy only toward the middle; ill-scented; very common, especially southern Wisconsin
............... A. Cotula - dog-fennel, stinking camomile.
1. Ray florets fertile; receptacle chaffy throughout; odorless
........... A. arvensis - corn chamomile.
ARTEMISIA - wormwood
(x = 9)
1. Receptacle hairy; leaves white-silky canescent; plants perennial and somewhat woody at base.
2. Leaves short, 1‑2 cm long, the segments filiform, 0.5‑1 mm wide; flowering stems ascending, to 5 dm tall, the vegetative stems forming mats; inflorescence a narrow panicle; very local on Mississippi River bluffs from Pierce Co. to Trempealeau Co., rarely weedy elsewhere (s = 2x)
.... A. frigida - prairie sage-wort.
2. Leaves 5‑15 cm long, the segments 2‑3 mm wide; flowering stems erect, to 9 dm tall; inflorescence a leafy panicle; sporadic adventive (s = 2x)
.... A. Absinthium - common wormwood, absinthe sage-wort.
1. Receptacle naked; leaves tomentose to glabrous; plants annual, biennial or perennial.
3. Disk florets staminate, their ovaries aborting; adult plants usually glabrous.
4. Biennial with a taproot; first year's lower leaves forming a basal rosette; leaves tomentose-glabrate; involucre 2‑3.5 mm long; common in sandy areas (s = 2x, 4x [within species])
..... A. campestris subsp. caudata - field wormwood or sage-wort, beach wormwood.
4. Robust perennial from a rootstock; lower leaves not in a rosette; leaves glabrous; involucre 2 mm long; very rare and sporadic (s = 2x)
.. A. Dracunculus - tarragon, estragon.
3. Disk florets producing achenes.
5. Leaves glabrous or glabrate, 2‑3 times pinnatisect or pinnatifid.
6. Perennial shrub; involucre 2‑2.5 mm long; bracts canescent or tomentose; rare garden escape (not naturalized) (s = 2x)
........ A. Abrotanum - southernwood.
6. Annual or biennial herbs; involucre 1‑2 mm long; bracts glabrous.
7. Inflorescence a dense racemose panicle with many spike-like branches from the leaf axils; heads erect; common weed (s = 2x)
.... A. biennis - biennial wormwood or sage-wort.
7. Inflorescence a broad terminal panicle with nodding heads; rare annual weed (s = 2x)
.... A. annua - annual wormwood or sage-wort.
5. Leaves tomentose at least on one surface, simple or dissected.
8. Leaves unlobed and linear-lanceolate, the margins regularly serrate to entire in the inflorescence, densely white-tomentose beneath, bright green-glabrous above; moist deep-soil prairies (s = 4x)
........ A. serrata - saw-tooth wormwood.
8. Leaves deeply lobed or cut, OR entire with the margins irregularly toothed.
9. Leaves delicately divided, the segments filiform, gray-green pubescent; rare garden escape (s = 2x)
.... A. pontica - Roman wormwood.
9. Leaf segments broader or leaves entire.
10. Leaves green-glabrate above, white-tomentose beneath, coarsely lobed; rare weed, eastern Wisconsin (s = 2x, 4x, 40, 6x)
...... A. vulgaris - mugwort, common wormwood.
10. Leaves pubescent on both surfaces.
11. Involucre 2‑4 mm long; leaves entire or irregularly toothed, densely white-tomentose beneath, tomentose to glabrate above; common prairie species (s = 2x, 4x)
........... A. ludoviciana subsp. ludoviciana - white sage, western mugwort.
11. Involucre 5‑8 mm long; leaves obtusely lobed, densely creamy white wooly; rare garden escape on Lakes Michigan and Superior (s = 2x)
........... A. Stelleriana - beach wormwood, dusty miller.
COTA - marguerite
(s = 2x; x = 9)
........ C. (Anthemis) tinctoria - golden marguerite, yellow chamomile.
(s = 2x; x = 9)
........ Leucanthemella (Chrysanthemum) serotina - giant daisy.
(s = 2x, 4x, 6x, 8x, 10x; x = 9)
........ Leucanthemum vulgare (Chrysanthemum Leucanthemum) - common or ox-eye daisy.
MATRICARIA & TRIPLEUROSPERMUM - wild chamomile
1. Ray florets none; disk florets greenish, 4‑lobed; heads short-stalked; achenes marked by elongate red-brown oil glands; very common throughout
........... M. discoidea (M. matricarioides) - pineapple-weed.
1. Ray florets white; disk florets yellow, 5‑lobed; heads long-stalked.
2. Receptacle conic at maturity; achenes ribbed, smooth, unmarked; involucre 2‑3 mm long; rare adventive (See also Anthemis Cotula)
.... M. Chamomilla (M. recutita) - sweet false camomile.
2. Receptacle hemispheric at maturity; achenes prominently ribbed, transversely rugulose or tuberculate with apical oil glands; involucre 3.5‑6 mm long; rare adventive on Lake Superior shores
......... Tripleurospermum (Matricaria) maritimum - scentless camomile.
TANACETUM - tansy
(x = 9)
1. Rays white, conspicuous, minute or absent; leaves largely unlobed OR 1-2 pinnatifid with broad ultimate segments.
2. Heads radiate, the rays 4‑8 mm long; leaves 1-2 pinnatifid; rare garden escape (s = 2x)
..... T. (Chrysanthemum) Parthenium - feverfew.
2. Heads discoid or rays minute; leaves crenate, rarely lobed at base; rare adventive (s = 2x, 6x)
.... Tanacetum (Chrysanthemum) Balsamita - costmary, mint-geranium.
1. Rays yellow and short (2‑4 mm) or absent; leaves 2-3 pinnatifid with narrow ultimate segments.
3. Heads disciform, 25‑100 or more in dense corymbs, 7‑10 mm in diam.; leaves glabrate; plants in dense, many stemmed clumps; common introduced weed (s = 2x)
..... T. vulgare - common tansy, golden-buttons.
3. Heads radiate, 3‑17 in loose corymbs, 1‑2 cm in diam., rays 2‑4 mm long; leaves tomentose; stems solitary; rare on inner beaches of Lake Michigan, Door Co. (s = 6x)
..... T. bipinnatum subsp. huronense - eastern or Lake Huron tansy.
Plants of Wisconsin
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