Today's image is courtesy of marcella2@Flickr (original image | BPotD Flickr Group Pool). Thank you!
Coltsfoot is native to much of Europe and neighbouring Asia and Africa. It is no surprise that historic medicinal and food uses caused it to be introduced to Canada, USA and New Zealand (Wikipedia also cites South America, but that doesn't match this list). Unfortunately, Tussilago farfara has qualities that make it somewhat invasive in the introduced countries: “Namura-Ochalska-Anna (1993) reports that the success of Tussilago farfara L. in colonizing disturbed environments, after its seeds reach the site and germinate, is a function of several of the important traits of this species: 1) tolerance of seedlings and juveniles to a wide range of changeable external conditions, 2) fast growth and development of individuals, 3) a high degree of adaptability in reaching successive stages of development, 4) guerilla type growth, 5) intense spreading and renewal of individuals of generative and vegetative origin, 6) high effectiveness of vegetative reproduction, 7) adaptable allocation of resources to above-, and underground shoots.” (quoted from the Global Invasive Species Database).
Fortunately, its preference for colonizing disturbed environments suggests it has relatively low impact on natural areas that haven't been degraded. Instead, it seems to be a problem in agricultural areas.
Invasive.org provides more photographs of the plant, including the leaves which emerge post-flowering. Kurt Stüber's botanical images library contains this illustration, as well.
Science / conservation resource link: In case you don't follow the garden's plant news weblog, here's a recent entry: A Blooming Crisis about the risk of extinction for over half of the world's magnolia species.
For us in Sweden, this little beauty tells us spring is on the way. It's our first wild flower to poke up it's head and splash some colour over the dirty drab roadsides. It always brings a smile to my face and I was just out, myself, and took some photos of it today. Thanks for showing it!
As you mention it can be quite a problem and it certainly is invasive, even here where it grows naturally in the wild. I live in a rural area with heavy clay soil and it has a great tendency for visiting my garden where it's not wanted. The visits are usually not of the 'short stay-kind' since the roots can be a real hassle to get rid off. I still love it though!
One thing I've noticed is that it follows in the tracks of the machines they use for cutting down trees (like Plantago major). I can find it quite far into the woods, but as you also mention - this area is already disturbed.
Pygge
This is the type of plant we are certain to need to get us through the upcoming global environmental upheavals.
If you pick the flowers when they start to bud, and preserve them in alcohol, with some sugar added, they make a fine cough remedy.
I also use the leaves later in the year. And the leaves infused in oil make for a fine antispasmodic rub.