I've recently noticed that all the flowers share the same internal names, being either red_flower or double_plant. This means that using the give command, we can only give ourselves the Poppy or the Sunflower, as those are the first in the memory.
Comments 6
Okay... the buttons work if you put in wooden_button and stone_button. Now we get to the flowers. All the flowers share two names, red_flower and double_plant. Since they all share the same name, we can only get the poppy and the sunflower
http://minecraft.gamepedia.com/Buttonwooden_button
This is no bug.
Search up on the wiki for the internal item name. If that doesn't work with /give, then it's a bug.