OF THE CAROLINAS & GEORGIA

Spermatophytes (seed plants): Angiosperms (flowering plants): Eudicots: Core Eudicots: Asterids: Campanulids: Asterales

WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Centaurea stoebe ssp. micranthos   FAMILY Asteraceae__   Go to FSUS key



SYNONYMOUS WITH PLANTS NATIONAL DATABASE:
Centaurea stoebe ssp. micranthos   FAMILY Asteraceae__

SYNONYMOUS WITH Floristic Synthesis of North America. BONAP (Kartesz, 2021)

Centaurea stoebe ssp. australis

SYNONYMOUS WITH Floristic Synthesis of North America. BONAP (Kartesz, 2015)

Centaurea stoebe ssp. micranthos

SYNONYMOUS WITH Flora of North America north of Mexico, vol. 19-20-21 (2006)

Centaurea stoebe ssp. micranthos

SYNONYMOUS WITH Floristic Synthesis of North America (Kartesz, 1999)

Centaurea biebersteinii

SYNONYMOUS WITH (MISAPPLIED) VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 179-24-003:

Centaurea maculosa   FAMILY Asteraceae__

 

COMMON NAME:
Spotted Knapweed, Bushy Knapweed


         To see larger pictures, click or hover over the thumbnails.

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913    pnd_cema4_001_lvd

        

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

USDA / Selected Weeds of the US. 1970    swus_page_383

        

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm140623_191b

June    Greenville County    SC

Swamp Rabbit Trail

Outer involucral bracts w pectinate (comb-like), scarious, blackish apices, per Vascular Flora of the Carolinas (Radford, Ahles, & Bell, 1968).


click here to see other plants that look similar to this COMPARE involucral bracts of Centaurea

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm140623_199

June    Greenville County    SC

Swamp Rabbit Trail

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm100702_004

July    Greenville County    SC

Swamp Rabbit Trail

Heads are discoid, but the large outer florets simulate ray flowers, per Wildflowers of the Southern Mountains (Smith, 1998).

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm100702_007

July    Greenville County    SC

Swamp Rabbit Trail

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm100702_008

July    Greenville County    SC

Swamp Rabbit Trail

Involucres urn-shaped, ~ 0.5" high, bracts tipped with a blackish fringe, per Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005).

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm100702_009

July    Greenville County    SC

Swamp Rabbit Trail

Leaves pinnatifid with linear segments, downy-hairy, minutely roughened, per Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005).

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm100702_011

July    Greenville County    SC

Swamp Rabbit Trail

Perennial 40-100cm tall, spreading-ascending, cespitose (tufted in clumps), per Vascular Flora of the Carolinas (Radford, Ahles, & Bell, 1968).

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm100702_018

July    Greenville County    SC

Swamp Rabbit Trail

Central flowers narrow, bisexual; marginal flowers enlarged, sterile, per Wildflowers of Tennessee, the Ohio Valley, and the Southern Appalachians (Horn, Cathcart, Hemmerly, & Duhl, 2005).

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm100702_050

July    Greenville County    SC

Swamp Rabbit Trail

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm100702_052

July    Greenville County    SC

Swamp Rabbit Trail

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm100702_064

July    Greenville County    SC

Swamp Rabbit Trail

The first year it has a basal rosette of deeply lobed leaves about 8" long, per Invasive Plants, Guide to Identification, Impacts and Control (Kaufman & Kaufman, 2007).

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm130823_476

August    Greenville County    SC

Swamp Rabbit Trail

Stems floccose [bearing tufts of long soft tangled hairs], per Vascular Flora of the Carolinas (Radford, Ahles, & Bell, 1968).

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm140831_142

August    Greenville County    SC

Swamp Rabbit Trail

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

Keith Bradley    kab_c_stoebe_micran_78803

August    Hamilton County    NY

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

JK Marlow    jkm121013_515516

October    Greenville County    SC

Swamp Rabbit Trail

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

Cindy Roche, Bugwood.org    bug_1350048

Month Unknown        

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

Ken Chamberlain, The Ohio State University, Bugwood.org    bug_1553216

Month Unknown        

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

John Cardina, The Ohio State University, Bugwood.org    bug_1557011

Month Unknown        

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

Montana Statewide Noxious Weed Awareness and Education Program Archive, Montana    bug_2153083

Month Unknown        

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

Leslie J. Mehrhoff, University of Connecticut, Bugwood.org    bug_5271008

Month Unknown        

image of Centaurea stoebe ssp. micranthos, Spotted Knapweed, Bushy Knapweed

Joseph M. DiTomaso, University of California - Davis, Bugwood.org    bug_5374337

Month Unknown        

 

 

WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Centaurea stoebe ssp. micranthos   FAMILY Asteraceae__

SYNONYMOUS WITH PLANTS NATIONAL DATABASE:
Centaurea stoebe ssp. micranthos   FAMILY Asteraceae__

SYNONYMOUS WITH Floristic Synthesis of North America. BONAP (Kartesz, 2021)
Centaurea stoebe ssp. australis

SYNONYMOUS WITH Floristic Synthesis of North America. BONAP (Kartesz, 2015)
Centaurea stoebe ssp. micranthos

SYNONYMOUS WITH Flora of North America north of Mexico, vol. 19-20-21
Centaurea stoebe ssp. micranthos

SYNONYMOUS WITH Floristic Synthesis of North America (Kartesz, 1999)
Centaurea biebersteinii

SYNONYMOUS WITH (MISAPPLIED) VASCULAR FLORA OF THE CAROLINAS (Radford, Ahles, & Bell, 1968) 179-24-003:
Centaurea maculosa   FAMILY Asteraceae__

 

Find by SCIENTIFIC NAME:

299

Forb
Biennial/Short-lived perennial

Habitat: Roadsides, disturbed areas, per Weakley's Flora

Non-native: Europe

Common in NC, rare in GA & SC

map
CLICK HERE to see a map, notes, and images from Weakley's Flora of the Southeastern US.

Click here to see a map showing all occurrences known to SERNEC, a consortium of southeastern herbaria. (Zoom in to see more detail.)


INVASIVE

This plant is causing problems in natural areas outside its native range, according to authorities such as:

 

LEAVES:
Simple: pinnatifid
Basal rosette & alternate

FLOWER:
Summer/Fall
Disc: Pinkish-purple
Rays: Absent
Inferior ovary
Bisexual, fertile (peripheral florets sterile)

FRUIT:
Summer/Fall
Blackish-brown
Achene

 

TO LEARN MORE about this plant, look it up in a good book!



 


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