Unknown plant in a known plant bed

My wife and I have had gardens ranging from Florida to Wisconsin, and we have a stranger that found it's way into our purple and white coneflower bed. It has green shoots that come out of the coneflower part, and looks like a broccolli. I'm attaching a picture to aid in identification.
Please Help! Thank you.

 

Thats known as aster yellows,its very contagious.
Bill

 

Sorry its very contagious to other plants.
Bill

 

I'm curious...what exactly is contagious to other plants??

Ed

 

Ed it will spread to certain other flowers so make sure you dispose of any infected plants. Ever have black spot go through your roses?
Bill

 

It's a pathogen spread from plant to plant by leaf hoppers. Once a plant is infected, it remains so and must be destroyed or it will act as a pathogen reservoir this summer and in future years.

Aster Yellows Coneflower Photo
Aster Yellows Factsheet

 

This is Gatun Keith. I'm not so sure. As I've said, we've been gardening for over 55 years and have fought most all pests, diseases, etc. and this doesn't look like a disease to us. Rather, it looks like a sport or mutation of the coneflower.
However, I'm a dope and you are probably right.

 

Wow, new one on me. So it turns out you have an unknown disease on a known plant.

 

I might add that spontaneous mutations have a pretty low occurence rate and to have one that bears a striking resemblance to a known plant disease must be extremely rare.

If you do believe it's a sport or mutation and don't want to destroy the plant, it might be prudent to dig up and move the coneflower to a 'quarrantine' area less the rest of your plants coincidentally get the same mutation.

 

Here's a similar pic of a plant infected with aster yellows, from Missouri Botanical Gardens:
http://www.mobot.org/gardeninghelp/images/Pests/Pest105.jpg

 

So lets get this straight, the diseases it harbours are contagious not the plant itself....excuse my ignorance

Ed

 

The disease is contagious - it will spread from this plant to other plants, unless the infected plant is removed and destroyed.

 

This particular disease is spread by leaf hoppers, much like Malaria is spread by mosquitoes. The plant itself is not the vector for disease, only the reservoir.

 

Boy, you've convinced me. I'm going out right now and dig it up. Into the burn pile it goes, along with all of it's neighbors.
Thanks a million for your replies.