Robert W. Freckmann Herbarium


KEY to the WISCONSIN ASTERACEAE

 

Tribe 8. SENECIONEAE - groundsel tribe

 

(Source: Kowal, Summer 1984; references: Fernald, 1950; Cronquist, 1980;

Gleason & Cronquist, 1991; FNA, 2006; edited by Kowal, 2006 August 1.)

 

1.   Perennials with green leaves arising individually from the ground from an underground rhizome; aerial stems consisting of scaly bracted flowering scapes arising before or as the leaves develop in early Spring.

 

2. Heads solitary, yellow, radiate with ray florets pistillate and disk florets staminate; radical leaves rounded-cordate, dentate AND very shallowly lobed; rare adventive

.........  TUSSILAGO - coltsfoot.

 

2. Heads numerous, creamy-white, radiate but with disk florets largely staminate or largely pistillate on different plants (imperfectly dioecious); radical leaves either merely dentate OR deeply lobed

.........  PETASITES - sweet-coltsfoot.

 

1.   Habit various but with well developed cauline leaves (though these may differ from the basal leaves).

 

3.    Corollas yellow to orange; heads usually with rays.

 

4.    Cauline leaves progressively reduced upward and lobed (unlike the basal leaves); perennials, usually with obvious vegetative reproduction

......  PACKERA - ragwort.

 

4.    Leaves more or less equal in size up the stem; annuals (perhaps rarely biennials).

 

5.  Rays conspicuous; leaves entire to weakly toothed; pubescence often copious; rare native, N Wisconsin         

........ TEPHROSERIS

 

5.  Rays inconspicuous or absent; leaves, or some of them, lobed to pinnatifid; pubescence short and often scant, crisp; introduced weeds

........  SENECIO - groundsel.

 

3.   Corollas whitish or creamy; heads without rays.

 

6. Annuals; heads disciform, with 2 to several marginal rows of pistillate florets with filiform corollas; leaves roughly the same size up the stem .

.....  ERECHTITES - fireweed.

 

6.    Perennials; heads discoid, containing only bisexual florets with 5‑lobed corollas.

 


 

7.  Heads with ca 13 phyllaries and 20‑40 florets; receptacle flat; larger leaves hastate; leaves roughly the same size up the stem; wet areas, S Wisconsin         

........  HASTEOLA - Indian-plantain

 

7.  Heads with ca 5 phyllaries and ca 5 florets; receptacle with a short conic projection in the center; leaves not hastate; leaves largest at base of the stem and becoming smaller upwards         

........  ARNOGLOSSUM - Indian-plantain

 

 

ARNOGLOSSUM - Indian-plantain

 

1.   Lower leaves lance-ovate or oval, entire or only shallowly crenate or dentate, with arcuate venation; wet prairies and pastures, calcareous marshes (s = 2x; x = 27)

...........  A. plantagineum (Cacalia tuberosa) - prairie or tuberous Indian-plantain.

 

1.   Lower leaves reniform, roundish or deltoid, lobed or coarsely angulate-dentate, with palmate venation.

 

2.  Leaves not glaucous; stem angled or sulcate, not glaucous; open woods, rare, S Wisconsin (s = 2x; x = 25) .

....  A. reniforme (A. Muehlenbergii) - great Indian‑plantain.

 

2.  Leaves glaucous beneath; stem terete or slightly striate, glaucous; mesic prairies and pastures, woodland edges (s = 2x; x = 28, 27, 26, 25) .

....  A. atriplicifolium - pale Indian-plantain.

 

 

ERECHTITES - fireweed

 

(s = 4x; x = 10)

 

........  E. hieraciifolius - fireweed.

 

 

HASTEOLA - Indian-plantain

 

(s = 4x; x = 10)

 

........  H. suaveolens - sweet or hastate Indian-plantain.

 

 


 

PACKERA - ragwort

 

(Source: Barkley, 1963; Mahoney, 2000; Mahoney and Kowal, 2007; edited by R. R. Kowal, 2007 February 6.)

 

(An F1 individual between each of the wetland species, P. aurea and

P. pseudaurea var. semicordata, with the mesic prairie subspecies,

P. paupercula var. savannarum, have been found in the field.)

 

(x = 22 & 23)

 

1.   Basal leaves cordate, subcordate or abruptly contracted to the petiole; plants typically of wet or moist habitats.

 

2.    Rays absent or inconspicuous, shorter than 6 (‑7) mm; basal leaf blades abruptly contracted to the petiole; vegetative reproduction absent; self-compatible, achenes abundant in all heads; Forest Co. (discoid; extinct?) , Apostle Islands in Lake Superior (radiate in all seen), rare (s = 8x; x = 22?)

....  P. indecora - northern squaw-weed, rayless ragwort.

 

2.    Rays prominent, longer than 6 mm; vegetative reproduction usually present (rhizomes or adventitious shoots on roots); self-incompatible, achene production sporadic.

 

3. Basal leaves cordate; vegetative reproduction by horizontal rhizomes [with adventitious shoots on roots as well in SW Canada]; shady, wet areas throughout, common (s = 2x; x = 22) .

....  P. aurea - golden ragwort.

 

3. Basal leaves subcordate to abruptly contracted to petiole; vegetative reproduction ONLY by adventitious shoots on roots, resulting in a simple, short, erect rootstock lacking vegetative rosettes (a "nubbin"); sunny, wet areas (e.g., wet prairies) in S Wisconsin, infrequent (s = 2x; x = 23)  .

....  P. pseudaurea var. semicordata ("P. semicordata") - heart-leaved ragwort.

 

1.   Basal leaves tapering to the petiole, sometimes rounded or subtruncate; plants typically of mesic or dry habitats (except for P. paupercula var. paupercula).

 

4.    Plants moderately to heavily arachnoid tomentose, especially on the undersides of the basal leaves, the upper stem and the involucral bases; asexual reproduction ONLY by adventitious shoots on roots, resulting in a simple, short, erect rootstock lacking vegetative rosettes (a "nubbin").

 

5. Cauline leaves fewer in number, less quickly reduced in size from base to inflorescence, the uppermost usually pinnatifid to the leaf tip; leaves deep spinach green, though superficially greyish due to the overlying pubescence; heads large; adventitious shoots sparse; infrequent in dry areas in W Wisconsin, e.g., bluff prairies (s = 4x; x = 23) .

.....  P. plattensis - prairie ragwort.

 

5.    Cauline leaves greater in number, rapidly reduced in size from base to inflorescence, the uppermost usually with an unlobed tip; leaves often pale green; heads in the common taxon (var. savannarum) small; adventitious shoots typically frequent to abundant.

 

6.  Adventitious shoots typically abundant, individuals frequently forming extensive clones; common S of the Tension Zone (s = 2x; x = 22)         

........  P. paupercula var. savannarum.

 

6.  Adventitious shoots only "frequent", clones with more sparsely distributed rosettes; sandy savanna at Perrot State Park, Trempealeau Co.(where the two previous species also occur in different habitats) , but may also occur elsewhere in the sandy floodplain of the Mississippi River (s = ca 6x)         

........  P. paupercula var. savannarum + P. plattensis?.

 

4.    Plants lightly pubescent to glabrous, except in the stoloniferous P. paupercula var. pseudotomentosa; vegetative reproduction by horizontal rhizomes and/or adventitious shoots on roots OR by stolons OR absent (though with vegetative rosettes on rootstock)

....  P. paupercula (s.l.) - northern ragwort.

.

7. Vegetative reproduction ONLY by adventitious shoots on roots; cauline leaves usually more numerous, more quickly reduced in size up the stem, uppermost often unlobed at leaf tip; common S of the Tension Zone (s = 2x; x = 22) .

......  var. savannarum.

 

7.    Vegetative reproduction by horizontal rhizomes (sometimes with sparse adventitious shoot production) OR by stolons OR absent; cauline leaves usually fewer and less quickly reduced in size up the stem, the uppermost often lobed to the tip.

 

8.  Stolons present and adventitious shoots on roots absent; plants typically pubescent; leaves broadly elliptical and abrubtly contracted to the petiole ("lollipop" leaves); sandy savannas of central Wisconsin (s = 2x; x = 22)         

........  var. pseudotomentosa.

 

8.  Stolons absent, rhizomes usually present, sometimes with adventitious shoots on roots in addition; plants lightly pubescent to glabrous; leaves narrowly elliptical to lanceolate, gradually narrowed to the petiole.

 

9.  Plants glabrous and gracile; heads smaller; wet or moist habitats along the shores of Lakes Superior and Michigan and in calcareous fens inland in SE Wisconsin (s = 2x; x = 22)  

.....  var. paupercula.

 

9.  Plants more or less pubescent and coarser; heads larger; moist to mesic habitats, frequent N of the Tension Zone (s = 4x; x = 22)  

..... - "Northern tetraploid complex".


 

 SENECIO - groundsel

 

(Source: Barkley 1963; edited by R. R. Kowal, 2006 Aug 1.)

 

(s = 4x in these species; x = 10)

 

1.   Rays absent; calyculate bracts well developed with distinct black tips; common

 ..........  S. vulgaris - common groundsel.

 

1.   Rays present, small; calyculate bracts usually without distinct black tips.

 

2     Plants densely and conspicuously glandular hairy; caluculate bracts about half as long as phyllaries; achenes glabrous; very rare adventive in Superior, WI

            ....  S. viscosus - sticky groundsel.

 

2     Plants sparsely hairy or subglabrate, scarcely or obscurely glandular; caluculate bracts many times shorter than phyllaries; achenes pubescent; very rare adventive in Iron Co. .

....  S. sylvaticus - woodland groundsel.

 

 

PETASITES - sweet-coltsfoot

 

(s = 2x or 3x; x =30)

 

1.   Leaves lobed more than two-thirds to base, reniform or suborbicular in overall shape, essentially glabrous above; wet habitats, N of the Tension Zone (s = 2x & 3x; x = 30) .....

...........  P. frigidus var. palmatus - northern sweet-coltsfoot.

 

1.   Leaves unlobed with margin dentate, deltoid-oblong to reniform-hastate, floccose above; wet habitats, infrequent, northernmost and, especially, NW Wisconsin (s = 2x; x = 30, 29)

...........  P. sagittatus (P. frigidus var. sagittatus) - arrowhead sweet-coltsfoot.

 

TEPHROSERIS

 

 (s = 2x; x = 24)

 

........  T. palustris (S. congestus) - marsh-fleabane, northern swamp groundsel.

 

 TUSSILAGO - coltsfoot

 

(s = 2x; x = 30)

 

........  T. Farfara - coltsfoot.


         
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