Half a pinhead....

.... In size.  And I am so, so happy to find it.  Possibly the best Christmas present ever.
 
Can you guess?  No maybe not - VodkaMan might know, HillyBlips might know and Nevermore might know.  TimGuru in Timaru would definitely know.
 
This plant is not much better than a seedling, but it does have siblings close by; and it's known as a host for Monarchs.
 
Anyway, I saw a Monarch butterfly hovering around this plant yesterday, and I hoped against hope that she would lay an egg.  I left the garden, because I didn't want to scare her off.
 
She has laid two eggs on this tiny, tiny plant, and this is one of them - and I am SO EXCITED.  If it hatches, I can move it to other plants, but I'm not sure they are big enough for many caterpillars.  In fact I know they are not. 

I would be ecstatic if I had a breeding colony of Monarchs.

(In order to get an image of this size, I used all the extension tubes on my 100mm macro lens - and it worked a treat).