Still called 'Crystal Pony'? By now i heard different names for her. 'Amber Leaf' is my personal favourite from those. Fits to her cutie mark and doesn't bring the sadness from King Sombras magic into her name.
So where you life wheat heads do have veins, like the ones visible in her cutie mark? Interesting. To be fair, I don't know what leaf of which tree it is - maybe a stylised oak leaf? - but i never thought of it as a wheat head.
Yes wheat heads do have a stem, but they dont have veins spreading to the left and right from this. Altought the single corns in a wheat head are have a sharp end, not such a round, like you see in her cutie mark. And the the small grass like stems growing ot of every single one are completly missing as you should already noticed, because it's so wonderful visible on most of the pictures in google. Oh and wheat is not brown or amber, as the name comes from the color, more golden. Besindes, when hundres of bronys and even the mlp wikia says it's a leaf, there are not much options: We are only a few tousand, who don't know how wheat looks like or we and you are both wrong or only you. Then why must the name fit her cutie mark so strictly? I don't find the word ballloon in PinkiePis name, gem in raritys or flower in cheerilees - so exceptions are not such a uncommon thing.