hairy four o’clock

(Mirabilis albida)

Conservation Status
hairy four o’clock
 
  IUCN Red List

not listed

     
  NatureServe

N5 - Secure

SNR - Unranked

     
  Minnesota

not listed

     
           
           
           
           
           
           
 
Description
 
 

Hairy four o’clock is an erect perennial rising from a thick, dark, fleshy or woody, taproot.

The stems are hairy, especially near the nodes. They are usually erect, but they may recline on the ground with the tips ascending.

The leaves are opposite, untoothed, hairy, either lance-shaped or lance-egg–shaped, almost stalkless, and taper to the base. They are spreading or strongly ascending at a 10° to 90° angle. The upper leaf surface is green to grayish or bluish green. The principal leaves are to ¾ wide.

The inflorescence is single branched clusters at the end of each stem branch and in the leaf axils. The clusters appear at the end of to ½ long hairy stalks. The clusters have 3 flowers each and are themselves hairy.

The flowers are ¼ to ½ wide. They have little or no fragrance. There are 5 pale pink petal-like sepals. The sepals are fused at the base forming a tube, then flare outward. There are 5 hairy bracts, to ¼ long, at the base of the flower that are fused into a pale green, sometimes tinged with purple, narrowly to widely bell-shaped cup. The flowers open in the late afternoon, giving this plant its common name, remain open all night, and close in the morning.

The fruit is a one-seeded achene. It is subtended by the persistent, bell-shaped fused bracts that have increased in size as the fruit developed, becoming to ½ long.

 
     
 

Height

 
 

8 to 40

 
     
 

Flower Color

 
 

Pale pink

 
     
 

Similar Species

 
 

Heart-leaved four o’clock (Mirabilis nyctaginea) has a hairless, distinctly forked stem. The leaves are wider, often hairless, and on longer leaf stalks. The bract cups are hairless.

Narrow-leaved four o’clock (Mirabilis linearis) has linear leaves.

 
     
 
Habitat
 
 

Dry. Prairies, hills, disturbed sites. Full sun.

 
     
 
Biology
 
 

Flowering

 
 

May to August

 
     
 

Pests and Diseases

 
 

 

 
     
 
Use
 
 

 

 
     
 
Distribution
 
 

Distribution Map

 

Sources

2, 3, 4, 5, 7, 24, 28, 30.

 
  4/18/2021      
         
 

Nativity

 
 

Native

 
         
 

Occurrence

 
 

 

 
         
 
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 Magnoliopsida (dicots)  
  Subclass Rosidae  
  Superorder Caryophyllanae  
 

Order

Caryophyllales (pinks, cactuses, and allies)  
 

Family

Nyctaginaceae (four o’clock)  
  Tribe Nyctagineae  
  Genus Mirabilis (umbrellawort)  
       
 

Subordinate Taxa

 
 

 

 
       
 

Synonyms

 
 

Allionia hirsuta

Mirabilis hirsuta

Oxybaphus hirsutus

 
       
 

Common Names

 
 

hairy four o’clock

hairy four o’clock

hairy four-o’clock

hairy umbrella-wort

 

 

 

 

 

 

 

 

 

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.

 

Axil

The upper angle where the leaf stalk meets the stem.

 

Bracts

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

 

Linear

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

 

Sepal

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

 
 
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.
 
 

Nancy Falkum

 
    hairy four o’clock      
           
 
MinnesotaSeasons.com Photos
 
 

Plant

 
    hairy four o’clock   hairy four o’clock  
           
    hairy four o’clock   hairy four o’clock  
           
 

Inflorescence

 
    hairy four o’clock   hairy four o’clock  
           
 

Flower

 
    hairy four o’clock      
           
 

Leaves

 
    hairy four o’clock   hairy four o’clock  
           
 

Infructescence

 
    hairy four o’clock      

 

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 a video, a YouTube link, or a cloud storage link.
 
 

 

 
     
     
       
       
 
Other Videos
 
     
     
     

 

Camcorder


Last Updated:

About Us | Privacy Policy | Contact Us | © 2021 MinnesotaSeasons.com. All rights reserved.