Helianthus hirsutus (Hairy Sunflower)

Plant Info
Also known as: Stiff-haired Sunflower, Whiskered Sunflower, Hispid Sunflower
Genus:Helianthus
Family:Asteraceae (Aster)
Life cycle:perennial
Origin:native
Habitat:part shade, sun; dry, open woods, thickets, fields, roadsides
Bloom season:August - September
Plant height:2 to 6 feet
Wetland Indicator Status:none
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

Pick an image for a larger view. See the glossary for icon descriptions.

Detailed Information

Flower: Flower shape: 7+petals

[photo of flower] One to 7 flowers at the top of the plant, most often 1 to 3. Individual flowers are 2 to 3 inches across with 8 to 15 ray flowers (petals) and 40+ yellow center disk flowers. Rays are sterile; the 5-lobed disk flowers have a 2-parted yellow style and a dark brown column of stamens that have a small yellowish to brown appendage at the tip.

[photo of phyllaries] Surrounding the base of the flower are 3 or 4 layers of lance-shaped, sharply pointed bracts (phyllaries), each phyllary usually irregularly fringed with short hairs around the edges, often stiff hairs on the surface, and the tip loose and ascending to spreading to curved. The set of phyllaries (involucre) is up to about ½ inch long (8 to 14 mm) and to 1 inch (10 to 25 mm) diameter.

Leaves and stem: Leaf attachment: opposite Leaf type: simple

[photo of leaves]  Leaves are mostly opposite, 2½ to 7 inches (6.5 to 18 cm) long and up to 3+ inches (8 cm) wide, narrowly lance to egg-shaped, broadest at or near the base, toothless to irregularly toothed, tapering to a sharply pointed tip, wedge-shaped to rounded to straight across at the base, the blade with 3 main veins, the lateral veins joined just above the base of the blade. Both surfaces are at least sparsely covered with short stiff hairs, the lower surface also gland-dotted.

[photo of stem and leaf stalks, and hairs on upper leaf surface] Leaf stalks are usually less than ¾ inch (4 to 20 mm) inch long, about ½ inch long mid-stem; uppermost leaves may be stalkless or nearly so. Stems are erect, unbranched, variably covered in stiff hairs, though the hairs can wear off leaving at least the lower stem smooth or with rough-textured stubble. Loose colonies may form from long rhizomes.

Fruit: Fruit type: seed without plume

[photo of fruit] The center disk forms a head of dry, brown seed, each seed up to 4.5 mm (~¼ inch) long and lacking a tuft of hair, but with 2 bristle-tipped scales at the top.

Notes:

Hairy Sunflower reaches the northwest edge of its range in Minnesota, where it is found in a range of habitats including woodland edges, roadsides and open grassy areas. While references state it may grow as tall as 6 feet (2 meters), 3 to 4 is pretty common. It is most similar to the related Woodland Sunflower (Helianthus strumosus) and the two overlap in a number of traits, which can make it difficult to distinguish them.

Helianthus hirsutus typically has 1 to 3 flower heads per stem, occasionally has as many as 6 or 7; stems are at least sparsely covered in stiff hairs, though hairs can wear off with age; leaves are broadest at or near the base, stiff-hairy on both surfaces, gland-dotted on the underside, and have 3 major veins, the lateral veins joining the midvein just above the leaf base; leaf stalks on mid-stem are ~½ inch long. It is noted that the column of stamens on the disk flowers has an appendage at the tip that is commonly yellowish, less often brown.

By comparison, H. strumosus is likely to have at least 5 flowers and as many as 15, leaf surfaces may be hairless or have some matted hairs on the underside, leaf stalks may be an inch or more long, and the stamen column on disk flowers is said to have a dark brown appendage. I do question the color of the appendage being anything approaching diagnostic since yellow appears to be common on many sunflowers, and the hairiness of leaves seems to vary depending on the reference (e.g. Gleason & Cronquist vs. Flora of North America), so H. strumosus is worth revisiting in the coming season. Another woodland sunflower species, Helianthus divaricatus, not present in Minnesota but is in Wisconsin, is also very similar overall, has leaves that are all stalkless, and hairless stems.

Please visit our sponsors

  • Minnesota Goose Garden

Native Plant Nurseries, Restoration and Landscaping Services ↓

Map of native plant resources in the upper midwest

  • Minnesota Native Landscapes - Your Ecological Problem Solvers
  • Spangle Creek Labs - Native orchids, lab propagated
  • Prairie Restorations - Bringing people together with the land
  • Landscape Alternatives
  • ReWild Native Gardens

More photos

Photos by K. Chayka taken in Ramsey County.

Comments

Have you seen this plant in Minnesota, or have any other comments about it?

Post a comment

Note: All comments are moderated before posting to keep the riff-raff out. An email address is required, but will not be posted—it will only be used for information exchange between the 2 of us (if needed) and will never be given to a 3rd party without your express permission.

For info on subjects other than plant identification (gardening, invasive species control, edible plants, etc.), please check the links and invasive species pages for additional resources.



(required)




Note: Comments or information about plants outside of Minnesota and neighboring states may not be posted because Id like to keep the focus of this web site centered on Minnesota. Thanks for your understanding.