Subject: How does the algal partner in lichen survive desiccation?

Lichen can survive long periods of desiccation, but how does the algal partner survive this? What 
adaptations does it have? Also, when the lichen undergoes sexual reproduction, as opposed to 
vegetative, how does the alga distribute itself independently? 
I find lichen really interesting as it's two or more species, but forms one structure. But I realised I don't 
know much about it, and I want to know more as it's pretty much everywhere. I was curious, and found 
some answers online, but not enough, and not specific enough for me! Would appreciate any pearls of 
wisdom. 

Re: How does the algal partner in lichen survive desiccation?