hairy sunflower

(Helianthus hirsutus)

               
Conservation Status

IUCN Red List

not listed

hairy sunflower

NatureServe

N4N5 - Apparently Secure to Secure

SNR - Unranked

Minnesota

not listed

Nativity

Native

Occurrence

 

Habitat

Dry. Woodland edges, meadows, roadsides.

 
Flowering

July to October

     
Flower Color

Yellow ray florets, yellow disk florets

     
Height

24 to 78

     
 
Identification

This is an erect, 24 to 78 tall, perennial forb that rises on usually a single stem from long-creeping, branched rhizomes. The rhizomes do not produce tubers. The plant sometimes forms dense colonies. The overall appearance is of a slender-stemmed, sometimes spindly plant with one or just a few flower heads.

The stems are erect; green, reddish-brown, or tinged with reddish-brown; and unbranched or sparingly branched near the top. They are moderately to densely covered with short, stiff, ascending to spreading hairs. They are sometimes nearly hairless toward the base.

There are usually 8 to 20 leaf nodes below the inflorescence. Lower and middle leaves are opposite, uppermost leaves are usually also opposite, sometimes alternate. Lower and middle leaf blades are narrowly lance-shaped to egg-shaped, relatively thick, and flat, not folded longitudinally. They are 2½ to 7 long and to 2 wide, 2 to 7 times as long as wide, becoming gradually smaller as they ascend the stem. They taper to a sharply pointed tip and may be wedge-shaped, rounded, or squared off at the base. The upper surface is rough to the touch with rough to the touch due to a moderate to dense covering of minute to short, stout hairs. The lower surface is moderately to densely covered with somewhat softer, spreading to loosely appressed hairs, and sparsely to moderately covered with stalkless, yellow glands. The margins are flat and finely toothed to almost untoothed. The leaves have 3 main veins, a prominent midvein and a pair of lateral veins that branch off the midvein at or slightly above the base and arch upward.

The inflorescence is a solitary head or an open cluster of 2 to 7 flower heads at the end of the stem. The flower heads are on stalks that are to 2 long.

The whorl of bracts at the base of the flower head (involucre) is to 1 in diameter. The bracts of the involucre are narrowly lance-shaped to lance-shaped and taper to a sharply pointed tip. The tips of the bracts are loosely ascending to spreading or bent backward.

The flower heads are 1¾ to 3½ wide, the disk is to 1 in diameter. There are 10 to 15 yellow ray florets and 40 or more yellow disk florets.

The fruit is an achene.

 
Similar
Species

 

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

 

 
Taxonomy

Family:

Asteraceae (aster)

 

Subfamily:

Asteroideae

 

Supertribe:

Helianthodae

 

Tribe:

Heliantheae (sunflower)

 
Synonyms

Helianthus hirsutus var. stenophyllus

Helianthus hirsutus var. trachyphyllus

Helianthus stenophyllus

 
Common
Names

hairy sunflower

hispid sunflower

oblong sunflower

rough sunflower

stiff-haired sunflower

 

 

 

 

 

 

 

Glossary

Achene

A dry, one-chambered, single-seeded fruit, formed from a single carpel, with the seed attached to the membranous outer layer (wall) only by the seed stalk; the wall, formed entirely from the wall of the superior ovary, does not split open at maturity, but relies on decay or predation to release the contents.

 

Bract

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

 

Involucre

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

 

Node

The small swelling of the stem from which one or more leaves, branches, or buds originate.

 

Rhizome

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

       
Visitor Photos
   
Share your photo of this plant.
 

This button not working for you?
Simply email us at info@MinnesotaSeasons.com.
Attach one or more photos and, if you like, a caption.

       
MinnesotaSeasons.com Photos
   

Colony

  hairy sunflower    
       

Plants

  hairy sunflower   hairy sunflower
       
  hairy sunflower    
       

Inflorescence

  hairy sunflower    
       

Flower Head

  hairy sunflower   hairy sunflower
       

Involucre

  hairy sunflower   hairy sunflower
       

Leaves

  hairy sunflower   hairy sunflower
       
  hairy sunflower   hairy sunflower
       
       

 

Camera

     
Slideshows
   
     
     
     

 

slideshow

       
Visitor Videos
       
Share your video of this plant.
   

This button not working for you?
Simply email us at info@MinnesotaSeasons.com.
Attach one or more videos or YouTube links and, if you like, a caption.

       
       
Other Videos
 
       
       
       
       

 

Camcorder


Last Updated:

About Us | Privacy Policy | Contact Us | © 2019 MinnesotaSeasons.com. All rights reserved.