prairie onion

(Allium stellatum)

               
Conservation Status

IUCN Red List

not yet assessed

prairie onion

NatureServe

NNR - Unranked

SNR - Unranked

Minnesota

not listed

Nativity

Native

Occurrence

 

Habitat

Dry. Prairies, hillsides. Full sun.

Flowering

July to September

     
Flower Color

White to pink

     
Height

1 to 2

     

Identification

This is an erect perennial forb rising from 2 to 5, sometimes more, clustered bulbs.

The bulbs are to 1 tall, to 1 wide, and egg-shaped. They are encased in a brownish or grayish membranous coating. They gradually taper to the stem.

Three to five basal leaves arise near together at the soil surface forming a basal rosette. They are shorter than the stem. They are 4 to 18 long, about wide, linear, flat, stiff, and solid, with a small ridge running the length of the blade. They sheath the stem near the soil surface. They remain after the flowers are fully formed.

A single, leafless, flowering stem (scape) rises from the center of the rosette of leaves. When in bud, the scape bends downward (nods) at the top, and the umbel faces toward the ground. By the time the flowers are fully mature the scape is erect and the flowers face upward.

The inflorescence is a single umbrella-like flowering cluster at the top of the scape. The cluster is shaped like half of a sphere. It has 8 to 35 flowers and no bulblets. There are two bracts at the base of the cluster that soon fall off.

The flowers are ¼ to ½ wide and star-shaped. They are composed of 6 white to pink tepals (3 petals and 3 sepals that are similar in appearance). They are on ¼ to ¾ long flower stalks, the inner ones on shorter stalks, the outer ones on longer stalks, like an umbrella. There is no floral fragrance, but the bulb and foliage have an onion-like scent.

The fruit is a seed capsule. The pedicels become stouter with the fruit, growing longer and bending abruptly upright from near the point of attachment.

 
Similar
Species

Meadow garlic (Allium canadense var. canadense) blooms much earlier, May to June. The scape never nods. It has 3 to 6 basally-sheathed leaves, attached only in the lower quarter or third of the stem. The leaves are flat and soft. Most or all of the flowers in the inflorescence have been replaced with bulblets. The flowers are bell-shaped.

Nodding wild onion (Allium cernuum var. cernuum) has tall, elongate, slender, and cone-shaped bulbs. The leaves are soft. The scape nods permanently, both when the flowers are in bud and when the flowers are fully open. The individual flowers of prairie onion are bell-shaped.

Textile onion (Allium textile) is a shorter plant, reacing only 4 to 12 at maturity. It blooms much earlier, May to June. It has only 1 or 2 basal leaves. The leaves are half-round, more or less straight, and solid, with a wide, rounded channel running the length of the blade. The scape never nods, and does not rise above the level of the leaves. The tepals are white, only rarely pink, and have red or reddish-brown midribs.


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

Comments

 


Taxonomy

Family:

Amaryllidaceae (amaryllis)

 

Subfamily:

Allioideae

 

Tribe:

Allieae

 
Synonyms

 

 
Common
Names

autumn onion

autumn wild onion

prairie onion

wild onion


 

 

 

 

 

Glossary

Bract

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

 

Elongate

Drawn out, lengthened.

 

Linear

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

 

Pedicel

In plants: the stalk of a single flower in a cluster of flowers. In Hymenoptera and Araneae: the narrow stalk connecting the thorax to the abdomen.

 

Scape

An erect, leafless stalk growing from the rootstock and supporting a flower or a flower cluster.

 

Sepal

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

 

Tepal

Refers to both the petals and the sepals of a flower when they are similar in appearance and difficult to tell apart. Tepals are common in lilies and tulips.

 

Umbel

A flat-topped or convex umbrella-shaped cluster of flowers or buds arising from more or less a single point.

       

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Habitat

  prairie onion    
       

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  prairie onion    
       

Inflorescence

  prairie onion   prairie onion
       

Infructescence

  prairie onion   prairie onion
       

Fruit

  prairie onion    
       
       

 

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  The Prairie Onion August 3, 2014
The Prairie Orchard
 
   
 
About

Published on Aug 9, 2014

A native species with a beautiful spray of pinkish blue flowers, this plant was part of the native American diet.

 
     

 

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