Funny! My 12 year old son got it in his letters as well and he knows the word because Aroids are my favorite. Something I talk about actually sinks in :)

I like to play Literati on Yahoo, which is very similar to scrabble. I like to use the challenge mode, where any word is allowed and its up to your opponent to challenge if they don't think it's a word. If they're right, your word disappears and your turn is over. If they're wrong, you get another turn. I win a lot of games because of all of the weird plant words I know. LOL!