The Naked Scientists

The Naked Scientists Forum

Author Topic: Are dandelions evolving beyond the reach of my lawn-mower?  (Read 21353 times)

Offline cheryl j

  • Neilep Level Member
  • ******
  • Posts: 1460
  • Thanked: 1 times
    • View Profile
I've been noticing lately the evolutionary battle between the lawn mower and the dandelions. The first time it was cut, all the dandelion flowers completely disappeared. A few weeks later I started noticing certain "strategies" to evade the lawnmower blades. A certain number of dandelions started blooming really close to the ground. Another segment of the dandelion population were normal height but they when they went to seed, they had these weird stems that would some how slide under the blade and pop right back up. Whoever says evolution is just a theory doesn't have to mow the lawn.
« Last Edit: 14/06/2012 17:22:58 by chris »


 

Offline CliffordK

  • Neilep Level Member
  • ******
  • Posts: 6321
  • Thanked: 3 times
  • Site Moderator
    • View Profile
Re: Natural selection and my lawn
« Reply #1 on: 08/06/2012 05:35:14 »
Don't forget, when you pull the dandelions, you will find a circle, maybe 6" in diameter of dead grass.  And it is difficult to get out the whole tap root.

Keep in mind that not all "Dandelions" are the same. 
You can have true dandelions, catsear, and hawksweed, all commonly confused for the same flower. 
 

Offline cheryl j

  • Neilep Level Member
  • ******
  • Posts: 1460
  • Thanked: 1 times
    • View Profile
Re: Natural selection and my lawn
« Reply #2 on: 10/06/2012 04:54:31 »
I read today that dandelions came over with the Pilgrims which I thought was kind of interesting.
 

Offline CliffordK

  • Neilep Level Member
  • ******
  • Posts: 6321
  • Thanked: 3 times
  • Site Moderator
    • View Profile
Re: Natural selection and my lawn
« Reply #3 on: 10/06/2012 06:11:27 »
I read today that dandelions came over with the Pilgrims which I thought was kind of interesting.

That may be true.  I tried to find true dandelions in my yard, and was unable to find them. 
Around hear, the Catsear and Hawksweed variety are much more common, which I believe are native to this region.

There are many invasive species such as the Himalayan blackberry that presumably were intentionally planted, then got out of hand.  Although the blackberries are good to eat  :)  In fact, many people can be reluctant to get rid of them.
 

Offline Don_1

  • Neilep Level Member
  • ******
  • Posts: 6890
  • Thanked: 7 times
  • A stupid comment for every occasion.
    • View Profile
    • Knight Light Haulage
Re: Natural selection and my lawn
« Reply #4 on: 13/06/2012 16:49:09 »
As Clifford has written, Dandelions are often confused with a number of similar wild plants, such Catsear, Prickly Ox Tongue, Sow Thistle, Hawksbeard, Autumn Hawk Bits and Hedge Mustard. Even the Chicory can be confused with dandelion until it gets to quite a size and later in the season when it displays itís blue flowers. These plants, however, have multi flowering heads or flower on long thin stems.

The Dandelion Taraxacum officinale and the most commonly confused Taraxacum obovatum  in many of its variants, are probably the plants you are referring to.


Taraxacum officinale


Taraxacum obovatum habitus


Taraxacum obovatum Vilanum

The Taraxacum officinale is also known as the Greater or Common Dandelion and is the largest of these plants. It has the more upright growing habit. The species of Taraxacum obovatum are generally smaller and tend to have ground hugging leaves and shorter flowering stems.

The stems of both do tend to grow according to the surrounding vegetation. The shorter the surrounding vegetation, the shorter the flowering stem needs to be. In long grass, the flower stems will grow long enough to put the flower above the grass, where it can be seen by insects. With a close cut lawn, growing a long flowering stem would be a waste of energy, since the flower can be easily seen even on the shortest stem.

I'm not sure how these plants got to North America, but as they were considered a good herbal remedy and can be used in culinary dishes, it wouldn't surprise me if they intentionally imported, but there would certainly be a very good chance that seed may have crossed with the Pilgrims as stow aways in other plants brought for the purpose of farming.
 

The Naked Scientists Forum

Re: Natural selection and my lawn
« Reply #4 on: 13/06/2012 16:49:09 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums