toothed evening primrose

(Oenothera serrulata)

               
Conservation Status

IUCN Red List

not yet assessed

toothed evening primrose

NatureServe

N5? - Secure

SNR - Unranked

Minnesota

not listed

Nativity

Native

Occurrence

Common

Habitat

Dry. Prairies, plains, bluffs. Full sun.

Flowering

June to July

     
Flower Color

Bright yellow

     
Height

Up to 24

     

Identification

This is an erect, perennial forb that rises up to 24 on usually clustered stems from a taproot rhizome caudex.

The stems are erect or recline on the ground with the tips ascending. They are grayish or whitish, at least above the middle, due to a covering of white, straight, stiff, appressed hairs. The are sometimes somewhat woody near the base.

The leaves are alternate, ¾ to 2 long, and less than ½ wide, linear, oblong, or narrowly inversely lance-shaped with the attachment at the narrow end. The margins are sometimes untoothed but are more often toothed with minute, sharp, forward-pointing teeth. The upper surface is hairy or sparsely hairy. The lower surface is hairy. The leaves fold in the midday sun in order to conserve water.

The inflorescence is a solitary flower borne in the upper leaf axils.

The flowers are to 1 wide and stalkless. The 4 petals are bright yellow and are fused at the base into a funnel-shaped, to ½ long hypanthium. The hypanthium is 4-angled and hairy, sometimes only on the angles. There are 8 stamens. The flowers open in the morning.

The fruit is a linear capsule, ½ to 1 long, 4-angled with rounded angles, and whitish due to a covering of white, straight, stiff, appressed hairs.

 
Similar
Species

 


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

Comments

Taxonomy
Sundrops were originally placed in the genus Oenothera when they were first described by Thomas Nuttall in 1818. In 1964 they were separated into thier own genus, Calylophus, by Peter Raven based strictly on morphological features, including a more or less shield-shaped stigma that was entire or only shallowly and broadly four-lobed. More recently, molecular analysis of the evening primrose (Onagraceae) family (W.L. Wagner et al., 2007) showed that sundrops should be regarded as representing one of fourteen specialized groups within Oenothera. They are now classified as section Calylophus.


Taxonomy

Family:

Onagraceae (evening primrose)

 

Subfamily:

Onagroideae

 

Tribe:

Onagreae

 

Genus:

Oenothera

 

Section:

Calylophus

 

Subsection:

Calylophus

 
Synonyms

Calylophus australis

Calylophus serrulatus

Meriolix intermedia

Meriolix oblanceolata

Meriolix serrulata

Oenothera serrulata var. typica

 
Common
Names

halfshrub calylophus

halfshrub sundrop

plains yellow primrose

serrateleaf eveningprimrose

toothed evening primrose

yellow evening-primrose

yellow sundrops


 

 

 

 

 

 

 

Glossary

Axil

The upper angle where the leaf stalk meets the stem.

 

Hypanthium

A cup-like tubular structure of a flower formed from the fused bases of sepals, petals, and stamens, that surrounds the pistil. Its presence is diagnostic of many families, including Rose, Gooseberry, and Pea.

 

Linear

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

       

Visitor Photos

   
Share your photo of this plant.

       
       
       
       

MinnesotaSeasons.com Photos

   

Plant

  toothed evening primrose   toothed evening primrose
       
  toothed evening primrose    
       

Inflorescence

  toothed evening primrose   toothed evening primrose
       
  toothed evening primrose    
       

Flower

  toothed evening primrose   toothed evening primrose
       
       

 

Camera

     

Slideshows

   
  Oenothera perennis SMALL SUNDROPS
Frank Mayfield
 
  Oenothera perennis SMALL SUNDROPS  

 

slideshow

     

Visitor Videos

   
Share your video of this plant.

     
     

Other Videos

 
  Botanist Jim Allison: flowering Sun Drops and Winged Elm
Panola Mountain
 
   
 
About

Uploaded on Jun 12, 2011

11 June 2011, Panola Mountain outcrop exploration with botanist Jim Allison: Here, Jim is explaining the Sun Drops. These are located in many spots atop the outcrop. Also identified, the Winged Elm

 
     

 

Camcorder

Last Updated:

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