Fasciation

Source: Wikipedia, the free encyclopedia.
Wyethia helianthoides or mule's ear wildflower (on right) showing fasciation
A "crested" saguaro cactus (Carnegiea gigantea), resulting from fasciation, located at Saguaro National Park (West), Arizona, U.S.

Fasciation (pronounced

apical meristem (growing tip), which normally is concentrated around a single point and produces approximately cylindrical tissue, instead becomes elongated perpendicularly to the direction of growth, thus producing flattened, ribbon-like, crested (or "cristate"), or elaborately contorted tissue.[1] Fasciation may also cause plant parts to increase in weight and volume in some instances.[2] The phenomenon may occur in the stem, root, fruit, or flower head
.

Some plants are grown and prized aesthetically for their development of fasciation.[3] Any occurrence of fasciation has several possible causes, including hormonal, genetic, bacterial, fungal, viral and environmental causes.

Cause

Fasciation can be caused by hormonal imbalances in the

better source needed
] hence bacterial infection is not an exclusive causation.

Additional environmental factors that can cause fasciation include fungi, mite or insect attack and exposure to chemicals.[8] General damage to a plant's growing tip[8] and exposure to cold and frost can also cause fasciation.[4][6] Some plants, such as peas and cockscomb Celosia, may inherit the trait.[8]

Genetic fasciation is not contagious, but infectious fasciation can be spread from infected plants to others from contact with wounds on infected plants, and from water that carries the bacteria to other plants.[9]

Occurrence

Although fasciation is rare overall, it has been observed in over 100 vascular plant

Cactaceae.[citation needed] Cresting results in undulating folds instead of the typical "arms" found on mature saguaro cactus.[12]

Some varieties of Celosia are raised especially for their dependably fasciated flower heads, for which they are called "cockscomb".

Salix sachalinensis 'Sekka') is another plant that is valued for its fasciations.[4][8]

Prevention

Fasciation that is caused by bacteria can be controlled by not using fasciated plants and disposing of fasciated material.[9] Avoiding injury to plant bases and keeping them dry can reduce the spread of bacteria.[9] Avoidance of grafting fasciated plants and the pruning of fasciated matter can also reduce the spread of bacteria.[9]

Examples

  • Fasciation
  • An example of fasciation, or "cresting," on a coneflower (Echinacea).
    An example of fasciation, or "cresting," on a coneflower (Echinacea).
  • Fasciation leading to two fully formed flower heads on a dandelion.
    Fasciation leading to two fully formed flower heads on a
    dandelion
    .
  • Fasciation on Digitalis. Note the larger thickened stem compared to the normal-sized flowering spike on the left.
    Fasciation on Digitalis. Note the larger thickened stem compared to the normal-sized flowering spike on the left.
  • Fasciation on a flowering cherry (Prunus) tree
    Fasciation on a flowering cherry (Prunus) tree
  • Asparagus (Asparagus officinalis) fasciation. Note the flattened state of the stem. Image published 1893.
    Asparagus (Asparagus officinalis) fasciation. Note the flattened state of the stem. Image published 1893.
  • Common dandelion displaying both regular (upper right) and fasciated (center) flowers.
    Common dandelion
    displaying both regular (upper right) and fasciated (center) flowers.
  • Fasciation on a lilac shrub.
    Fasciation on a
    lilac
    shrub.
  • Fasciation on a Phacelia campanularia or California bluebell wildflower.
    Fasciation on a Phacelia campanularia or California bluebell wildflower.
  • Fasciated showy daisy (Erigeron speciosus).
    Fasciated showy daisy (Erigeron speciosus).
  • Fasciated Crookneck Squash
    Fasciated Crookneck Squash
  • Pictured is common dandelion with multiple fully formed flower heads and a notably wide stem joined in fascination.
    Fasciation seen on
    common dandelion
  • Picture showing a regular flower of Geranium palustre on the left, and a fasciated one with a double amount of petals and two pistils.
    Regular (left) and fasciated (right) geranium flowers
  • Fasciation in Odontonema tubaeforme (Bertol.) Kuntze inflorescence.
    Fasciation in the inflorescence of a cultivated Odontonema tubaeforme plant.
  • Fasciation exhibited on Sedum sexangulare.
    Fasciation exhibited on Sedum sexangulare.
  • Fasciation on a zinnia that resembles a smiley face
    Fasciation on a zinnia that resembles a smiley face

See also

References

  1. .
  2. .
  3. ^ Morris, Scott. "Fasciation in Flowers – What You Need To Know". Gardentoolbox. Archived from the original on 10 January 2014. Retrieved 10 January 2014.
  4. ^ a b c d e Lerner, B. Rosie (September 2007). "Fascinating Fasciation". Purdue University Extension. Archived from the original on December 15, 2012. Retrieved July 3, 2012.
  5. ^ a b "Fasciation in Vegetables and Fruits". University of Delaware Cooperative Extension. May 27, 2011. Archived from the original on February 7, 2015. Retrieved July 6, 2012.
  6. ^ Tilford, P.E. (1936). "Fasciation of Sweet Peas caused by Phytomonas fascians n.sp". Journal of Agricultural Research. 53 (5): 383–394. Retrieved July 7, 2012.
  7. ^ a b c d e Swift, Curtis E. (April 12, 1999). "Fasciation: Fascinating distortions of the plant world". Colorado State University Extension. Archived from the original on June 30, 2012. Retrieved July 3, 2012.
  8. ^ a b c d "Managing Pests in Gardens: Floriculture: Diseases: Fasciation". Statewide Integrated Pest Management Program, Agriculture and Natural Resources, University of California. October 13, 2008. Archived from the original on September 15, 2022.
  9. S2CID 83559228
    .
  10. .
  11. ^ "Campus Arboretum". University of Arizona. 2008-08-20. Archived from the original on 2010-01-06. Retrieved 2010-01-14.

Further reading

External links