Plant Image
Flowers
Aspen Creek Tr - Sue Smith


Yavapai County Native & Naturalized Plants

Cirsium arizonicum - Arizona thistle

Synonyms: Cirsium nidulum, Cnicus arizonicus
Plant Form: Forb or Subshrub

Family: Asteraceae


   
 
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Flowers
Clark Springs Tr
Sue Smith
Leaves
Aspen Creek Tr
Sue Smith
Plant - summer
Clark Springs Tr
Sue Smith
Plant - summer
Aspen Creek Tr
Sue Smith
Stem
Clark Springs Tr
Sue Smith
Stem
Aspen Creek Tr
Sue Smith
Forb Plant Description

Origin: Native   Life Cycle: Biennial or perennial
General Desc: Stems 1 to several, erect or ascending, often hairy; flower head always appears partly open, bracts never allow it to spread into the typical wide disc shape of other thistles.
Identification notes: Stems woolly, erect, branching; cylindric flower heads of typically red (sometimes pink, orange, purple) disc flowers; spines of middle flower bracts shorter, inner bracts have elongated reddish tips; leaves are persistently densely hairy on underside.
Height: 1 to 5 feet


Habitat

Habitat Description: Variety of upland habitats, including desert scrub, grasslands, juniper woodlands, and openings in conifer forests.
Plant Communities: Desert Scrub, Semidesert Grasslands, Pinyon Juniper Woodland, Montane Conifer Forest
Elevation: 3000 - 9500 feet


Flower Characteristics

Color: Red to orange or pink to light purple     Shape: Daisy or dandelion-like not in clusters     Tubular: N     Flowering Period: May - Oct
Description: As many as 100 flower heads per plant; each flower head, 5/8 to 2 inches long, made up of thin tubular disc flowers held tightly by layers of spiny bracts. The bracts have a central white line and are arranged in a tight spiral.


Leaf and Stem Characteristics

Leaf Color: Grayish-green     Leaf Type: Simple     Leaf Shape: Triangular     Leaf Margin: Toothed     Leaf Attachment: Basal and alternate     Leaves Clasp: Y
Hairs: Leaves and stems     Spines: Y
Leaf Description: Very hairy; basal leaves are 1-1/2 to 12 inches long and have spine-tipped teeth or lobes; stem leaves are usually clasping.


Fruit and Seed Characteristics

Fruit Color: Brown   
Fruit Type: Achene
Fruit Notes: Smooth, compressed, 1/4 inch long, topped with plumose bristles.
Seed Notes: Produces seeds that are an important food source for birds, especially for Northern Cardinals and Lesser Goldfinches.



  Arizona Cooperative Extension
Yavapai County
840 Rodeo Dr #C
Prescott, AZ 86305
(928) 445-6590
Version 8.0  
http://cales.arizona.edu/yavapaiplants/SpeciesDetailForb.php  
Last Updated: Dec 13, 2022
Content Questions/Comments: Email Matt Halldorson  
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