Man, I love this site. I get answers to questions I didn't even know I had! I have one of those in an area I haven't tamed yet. Thanks for identifying it, now I won't pull it out. Thanks!

Now I'm puzzled as to why you asked for an id (using a photo dated 2015) if you already knew its name and had posted about it before? Your plant hasn't got typical Ixora foliage which is why I didn't recognise it. I'm thinking it could be Ixora 'Siam Ribbon' which has curled and distorted foliage. Reading up on its requirements I doubt it will flower in a terrarium as it likes full sun. Siam Ribbon

I had not completely ruled out the idea of it being a weed. I didn't want to assume and yank it immediately due to finding rose bushes and a couple other plants that were making a come back from the year before. There are three of these 'weedy ground orchids' that are ironically growing evenly with two or so foot spacing in between. Plus my neighbors sunflowers wiggled their way through the fence into our yard. Thought I'd do some investigating and ask around before I went ahead and pulled the suckers out. :) Thanks for the input everyone! much appreciated

Looks like a California poppy seedling to me, Eschscholtzia californica.