southern blue flag

(Iris virginica var. shrevei)

Conservation Status
southern blue flag
 
  IUCN Red List

not listed

     
  NatureServe

N5 - Secure

SNR - Unranked

     
  Minnesota

not listed

     
           
Wetland Indicator Status
     
  Great Plains

OBL - Obligate wetland

     
  Midwest

OBL - Obligate wetland

     
  Northcentral & Northeast

OBL - Obligate wetland

     
           
 
Description
 
 

Southern blue flag is a 20 to 40 tall, erect, perennial forb that rises on a single stem from a thick, creeping, freely-branching rhizome and fleshy roots. It often forms dense clumps.

The stems are erect to arching and usually have 2 or 3 branches. They seldom fall over after flowering. They are shorter than the leaves so that the leaves rise above the flowers.

Basal leaves are narrowly sword-shaped, green to grayish-green, 23½ to 31½ long, and 1 to 13 16 wide. They are erect and commonly arching near the top. There are 1 or 2 leaves on the stem subtending each branch. Stem leaves are similar to the basal leaves but shorter.

The inflorescence is 2 or 3 flowers at the end of the stem and 1 or 2 flowers at the end of the branch. The cluster emerges from an enveloping pair of large bracts (spathes).

The flowers are 3 to 3½ wide. There are 3 petals and 3 petal-like sepals, all of which are fused at the base into a to ¾ long tube. Each sepal is egg-shaped to oval, widely spreading, arched, 1½ to 2¾ long, and ¾ to 1½ wide. It is abruptly or gradually narrowed toward the base (clawed) and broadly expanded toward the tip. It is pale blue to purple near the tip quickly fading to white with darker blue or purple veins toward the middle. There is a bright yellow patch near the throat. The claw is green in the center, surrounded by bright yellow, with purple veins. What appears to be an upper lip is actually a branch of the style. The highly modified style is enlarged and divided into 3 branches. Each petal-like style branch covers the lower portion of a one sepal, extending just beyond the narrowed claw and concealing the stamens. The style branch is 13 16 to 1 long, distinctly ridged, and flared at the tip. It does not have ear-like lobes at the base. The 3 petals are smaller than the sepals. They are lance-shaped to spatula-shaped, erect, 1¼ to 2¾ long, and to 1¼ wide. They are often notched at the tip. The flowers last 1 to 4 days and are somewhat fragrant. All white flowers are found, though rarely.

The fruit is a green, elliptical to egg-shaped, three-sided, 1¼ to 2 long, to ¾ in diameter capsule. It is rounded-triangular in cross section.

 
     
 

Height

 
 

20 to 40

 
     
 

Flower Color

 
 

Lavender to violet

 
     
 

Similar Species

 
  Northern blue flag (Iris versicolor) top of the stem is equal to or higher than the leaves. The sepals and petals are darker in color, violet blue. The patch at the base of the sepals is yellowish-green, not bright yellow. The 3 petals are not notched at the tip.  
     
 
Habitat
 
 

Wet. Meadows, swamps, marshes, and streambanks. In water less than 40 deep. Full to partial sun.

 
     
 
Biology
 
 

Flowering

 
 

May to July

 
     
 
Use
 
 

 

 
     
 
Distribution
 
 

Distribution Map

 

Sources

2, 3, 4, 5, 7, 24, 28.

 
  6/28/2017      
         
 

Nativity

 
 

Native

 
         
 

Occurrence

 
 

Common

 
         
 
Taxonomy
 
  Kingdom Plantae (green algae and land plants)  
  Subkingdom Viridiplantae (green plants)  
  Infrakingdom Streptophyta (land plants and green algae)  
  Superdivision Embryophyta (land plants)  
  Division Tracheophyta (vascular plants)  
  Subdivision Spermatophytina (seed plants)  
  Class Liliopsida (monocots)  
 

Order

Asparagales (agaves, orchids, irises, and allies)  
 

Family

Iridaceae (irises and allies)  
  Subfamily Iridoideae  
  Tribe Irideae  
 

Genus

Iris (iris)  
  Subgenus Limniris  
  Section Limniris  
  Series Laevigatae  
  Species southern blue flag (Iris virginica)  
       
 

Synonyms

 
 

Iris shrevei

Iris versicolor var. blandescens

Iris versicolor var. shrevei

 
       
 

Common Names

 
 

Shreve’s iris

southern blue flag

southern blueflag

Virginia blue flag

 
       

 

 

 

 

 

 

 

 

Glossary

Bract

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

 

Claw

A stalk-like narrowed base of some petals and sepals.

 

Linear

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

 

Rhizome

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

 

Sepal

An outer floral leaf, usually green but sometimes colored, at the base of a flower.

 

Spathe

One or two large bracts that subtend, hood, or sometimes envelope a flower or flower cluster, as with a Jack-in-the-Pulpit.

       
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Kirk Nelson
       
  southern blue flag   southern blue flag
       

Southern blue flag iris, on the shore of Pickerel Lake

  southern blue flag   southern blue flag
       

Found on the shore of Pickerel Lake

  southern blue flag   southern blue flag
       
MinnesotaSeasons.com Photos
   

Plant

  southern blue flag    
       

Inflorescence

  southern blue flag    
       

Flower

  southern blue flag   southern blue flag
       
  southern blue flag   southern blue flag
       
       

 

Camera

     
Slideshows
   
  Virginia Blueflag (Iris virginica)
Bill Keim
 
  Virginia Blueflag (Iris virginica)  
     
  Iris virginica (Southern Blue-Flag)
Allen Chartier
 
  Iris virginica (Southern Blue-Flag)  

 

slideshow

       
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Other Videos
 
  blue flag (Iris virginica)
UFInvasivePlantsEDU
 
   
 
About

Uploaded on May 19, 2010

Aquatic and Invasive Plant Identification Series by the UF/IFAS Center for Aquatic and Invasive Plants ( http://plants.ifas.ufl.edu ) and the Florida Fish and Wildlife Commission, Invasive Plant Management Section.

For more information about blue flag, go to http://plants.ifas.ufl.edu/node/206

Video editor/videographer - Phil Chiocchio

   
       
  Southern Blue Flag Iris
natvikdesign
 
   
 
About

Published on Jun 28, 2012

Wild Iris (Iris virginica) in wetland restoration near Ridgetown, Ontario

   
       

 

Camcorder

         
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Kirk Nelson
5/31/2019

Location: Mississippi National River and Recreation Area - Coldwater Spring

southern blue flag


Kirk Nelson
6/2/2017

Location: Lilydale Regional Park

Southern blue flag iris, on the shore of Pickerel Lake

southern blue flag


Kirk Nelson
6/13/2014

Location: Lilydale Regional Park

Found on the shore of Pickerel Lake

southern blue flag


     
     
 
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