orange hawkweed

(Pilosella aurantiaca)

               
Conservation Status

IUCN Red List

not yet assessed

orange hawkweed

NatureServe

NNA - Not applicable

SNA - Not applicable

Minnesota

not listed

Weed Status

Invasive

County noxious weed in Becker and Koochiching Counties.

Nativity

Native to northern and central Europe. Introduced as an ornamental to Vermont before 1875. Escaped cultivation many times. Now naturalized in North America.

Occurrence

Widespread but sporadic

Habitat

A variety of habitats, including grasslands, forests, and wetlands, bogs, fields, roadsides, meadows, disturbed sites.

 
Flowering

May to August

     
Flower Color

Orange to red

     
Height

6 to 24

 

Identification

This is an erect, perennial forb that rises on a rosette of basal leaves and a single flowering stem from a long or short, horizontal, underground stem (rhizome) and shallow fibrous roots. It is usually 6 to 14 tall at maturity, though some individuals may reach 24 or more in height. It reproduces mostly by producing 4 to 12 aboveground runners (stolons) that creep along the ground and produce a new plant at the tip. The stolons are leafy and 4 to 12 long. It sometimes forms dense mats. Stems and leaves, when broken, exude a milky juice.

The basal rosette consists of 3 to 8 leaves. Basal leaves are spatula-shaped to inversely lance-shaped, 1¾ to 8 long including the leaf stalk, and to 1wide, 3 to 5 or more times longer than wide. Most leaves are no more than 2¾ long. The leaf blades are wedge-shaped at the base and blunt at the tip. The upper and lower surfaces are covered with long, soft, straight hairs and short, branched, star-shaped hairs. The margins are untoothed. Basal leaves are present at flowering time.

A single unbranched flowering stalk rises from the center of the rosette. The stem is covered with 1 32 to long soft, straight hairs. Toward the top it is also covered with star-shaped hairs and stalked glands. There is sometimes as single leaf, rarely 2 leaves, on the stem. Stem leaves are similar to basal leaves but smaller.

The inflorescence is a branched, compact, more or less umbrella-like array of flower heads at the end of the stem. There are usually 3 to 7, sometimes up to 12, flower heads in the array.

There is a whorl of 13 to 30 or more lance-shaped to linear bracts at the base of the flower head (involucre). The involucre is 3 16to 5 16 long and bell-shaped. The bracts of the involucre (phyllaries) are covered with long, soft, straight hairs; short, branched, star-shaped hairs; and stalked glands.

Each flower head is ¾ to 1 in diameter, has 25 to 120 or more ray florets, and has no disk florets. The ray florets are to 9 16 long and orange to reddish-orange. Rays near the center of the flower head are usually yellow, at least near the base. The flowers appear from May to August, peaking in June. When they dry they become scarlet or purple.

The fruit is a 1 32 to 1 16 long, single-seeded capsule (cypsela). The cypsela is round in cross section and narrowed at the base. It has 10 longitudinal ribs and a tuft of 25 to 30 or more white, barbed bristles attached to the end. It is dispersed by wind.

 
Similar
Species

No similar species. This is the only hawkweed with orange flower heads.


Distribution Distribution Map   Sources: 2, 3, 4, 5, 7, 22, 28.

Comments

Taxonomy
Until recently, plants in the genus Pilosella were grouped as a subgenus of Hieracium. Distinct features of the cypsela, absence of hybridization between groups, and, in some species, the presence of runners (stolons) and/or red lines on the lower (abaxial) ligule surface, support the segregation of these species into a separate genus. Some sources, including GRIN38 and The Plant List36, now classify this species as Pilosella aurantiaca. Most sources, including NCBI34, ITIS37, PLANTS3, UniProt33, FNA45, and Chadde62, continue to classify it as Hieracium aurantiacum.

Pollen Allelopathy
Pollen allelopathy occurs when the pollen of one species is transferred to another species. The transferred pollen then releases toxins which interfere with the growth of pollen tubes, the receptivity of the stigma or style, respiration, germination or growth of the seedling, production of chlorophyll in leaves, or production of seeds. Orange hawkweed is one of the six known pollen allelopathic plants.


Taxonomy

Family:

Asteraceae (aster)

 

Subfamily:

Cichorioideae

 

Tribe:

Cichorieae (lettuce)

 

Subtribe:

Hieraciinae

 
Synonyms

Hieracium aurantiacum

 
Common
Names

devil’s-paintbrush

fox-and-cubs

grim-the-collier

orange hawkweed

orange king-devil

red daisy


 

 

 

 

 

 

 

 

 

 

Glossary

allelopathy

The release of a chemical toxin by one plant to inhibit the growth or germination of nearby competing plants.

 

bract

Modified leaf at the base of a flower stalk or flower cluster.

 

cypsela

A dry, one-chambered, single-seeded seed capsule, formed from a single carpel, with the seed attached to the membranous outer layer (wall) only by the seed stalk; the wall, formed from the wall of the inferior ovary and also from other tissues derived from the receptacle or hypanthium, does not split open at maturity, but relies on decay or predation to release the contents.

 

involucre

A whorl of bracts beneath or surrounding a flower or flower cluster.

 

linear

Long, straight, and narrow, with more or less parallel sides, like a blade of grass.

 

phyllary

An individual bract within the involucre of a plant in the Asteraceae family.

 

rhizome

A horizontal, usually underground stem. It serves as a reproductive structure, producing roots below and shoots above at the nodes.

 

stolon

An above-ground, creeping stem that grows along the ground and produces roots and sometimes new plants at its nodes. A runner.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

       

Visitor Photos

   
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Bill Reynolds


The hawkweed grew in great abundance in my yard in St Louis Co. My honeybees only gathered from the hawkweed in years there wasn't much else blooming. The Tansy was another one they wouldn't use much.

  orange hawkweed    

Ed Oliveras


  orange hawkweed    

       
       

MinnesotaSeasons.com Photos

   

Plant

  orange hawkweed    
       

Inflorescence

  orange hawkweed    
       

Flower Head

  orange hawkweed   orange hawkweed
       
       

 

Camera

     

Slideshows

   
  Orange Hawkweed or Devil's Paintbrush (Hieracium aurantiacum)
Andree Reno Sanborn
 
  Orange Hawkweed or Devil's Paintbrush (Hieracium aurantiacum)  
 
About

s "orange hawkweed" "devil's paintbrush"

 
     
  Orange Hawkweed (Pilosella aurantiaca)
Bill Keim
 
  Orange Hawkweed (Pilosella aurantiaca)  
     
  Folk po našem * Sober Folk
drnespor
 
   
 
About

Published on Jun 18, 2012

Cz: Květinou je Jestřábník oranžový (Hieracium aurantiacum) a interprety písně Vždystřízlivci se skvělým sólistou. www.drnespor.eu: Svépomocné příručky, relaxační nahrávky, smích atd. Oblíbená jóga: www.biharyoga.net. Oblíbený čchi-kung: www.zy-qigong.cz, www.zyq.sk. Svépomoc: www.anonymnialkoholici.cz. AZ! Vše dobré!

English: Enjoy! Original recording of a folk song by Weversober. The flower is orange hawkweed or Hieracium aurantiacum. www.drnespor.eu: Papers, relaxation recordings, laughter, etc. My Favorite Yoga: www.biharyoga.net. My Favorite Qigong: www.springforestqigong.com, www.zyqigong.org. Self-help: www.aa.org. Best Wishes!

 

 

slideshow

     

Visitor Videos

   
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Other Videos

 
  Unwanted: Orange Hawkweed in Bend
Bend Bulletin
 
   
 
About

Published on Jun 15, 2012

Dan Sherwin, vegetation manager for Deschutes County, describes why the county wants to find and kill orange hawkweed. The pretty plant is an invasive weed.

 
     
  Orange Hawkweed (Pilosella Aurantiaca) / Fox-and-cubs - 2012-06-12
W3stlander
 
   
 
About

Published on Jun 18, 2012

Pilosella aurantiaca (Fox-and-cubs, Orange Hawkweed,[2]:208 Tawny Hawkweed, Devil's Paintbrush, Grim-the-collier) is a flowering plant of the family Asteraceae.

Oranje havikskruid (Hieracium aurantiacum, synoniem: Pilosella aurantiaca) is een vaste plant die behoort tot de composietenfamilie (Asteraceae). Dit exemplaar is bijna zeker verwilderd uit het nabijgelegen volkstuinencomplex "Ons Ideaal", daar staan er meer.

 
     
  Orange Hawkweed flowers on my field [July 7, 2012 13:06]
Tim Acheson
 
   
 
About

Published on Jul 10, 2012

A patch of wild Orange Hawkweed flowers on my hay meadow in Braughing. This weed is also known as "Devil's Paintbrush" or "Fox and Cubs". (Hieracium aurantiacum, syn. Pilosella aurantiaca.) At first glance the bloom looks a bit like an miniature gerbera or anemone. Photo: https://www.dropbox.com/s/mg87pl628o8hvkn/2012-07-07%2013.09.09.jpg

 
     

 

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Visitor Sightings

   
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Ed Oliveras
6/24/2004

Location: St. Croix State Park

orange hawkweed


Bill Reynolds
6/23/2004

Location: St Louis Co.

The hawkweed grew in great abundance in my yard in St Louis Co.  My honeybees only gathered from the hawkweed in years there wasn't much else blooming. The Tansy was another one they wouldn't use much.

orange hawkweed


     
     
 

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