If you're like me, or like millions of other Americans who grew up where melons could be had, you probably answered something like "spit them". When we eat watermelons1, we eat a big bite of delicious fruit and are left with the inedible seeds. Those, we spit out. (If you're a kid and it's a lazy summer afternoon, you have contests to see who can spit them the farthest.) We've taken in the part that nourishes us (yum, watermelon!) and gotten rid of the part we don't need (ptui, seeds).
Now what if the seeds were poison, and watermelon were the only thing we had to eat? We'd be like saltwater cordgrass (Spartina alterniflora). Native to the east coast of the USA, this plant grows in coastal sand dunes, where the only water available to it is thick with salt. In a habitat like that, most grasses quickly shrivel, drinking deep of seawater and still dying of dehydration. Spartina, though, thrives.
|Spartina leaves. See the clumps of salt?|
Image source: Field Studies Council. "Spartina." Retrieved 10 Aug 2012 from <http://www.theseashore.org.uk/theseashore/Saltmarsh%20section/species/Spartina.html>
1. The older cultivars, not the new "seedless" ones.