Where the shape comes from
A single blade pushing up out of the ground, root hairs spreading below — the plant radical cut in half. Doubled and set side by side it becomes 艸, the grass radical seen everywhere today as 艹, so that every character topped with a grass crown is, underneath, two of these blades standing together; alone, it is almost never written, kept mostly for the dictionary’s own bookkeeping.
汉字 filed under 屮
No published character on HSK Guide is filed under this radical yet. 汉字库.