The Chinese pictograph for “grass" was initially drawn like this:
Later it was altered to look like this:
In this altered form, the top part of the character remains a literal likeness of grass, as shown above; the lower part was added to hint the pronunciation of the word, which came to be standardized as [cǎo]. The word, in its altered form, is both pictographic and phonetic (sort of).
草 means grass, and it also implies "common" and "wild" because grass thrives on its own just about anywhere there is soil and moisture. Hence the term 草民 [cǎo mín], "grass people," which stand for, as they put it in English, "grassroots." This term is often used by the common folk to refer to themselves humbly and ironically, in a kind of mild protest against the establishment that neglects them.
In this connection, there is the term 草莽 [cǎo mǎng], "grass growing wild," which is often used to refer to bandits or outlaws. When cǎo mín lose their patience and rebel, they become cǎo mǎng.
One of the most famous poetic lines in China is 野草烧不尽，春风吹又生 [Yě cǎo shāo bù jìn, chūn fēng chuī yòu shēng] - "Wild fire cannot destroy grass; when spring breeze returns, grass grows once again." The line is by the poet Bai Juyi, who lived from 772 to 846, in the Tang Dynasty.
草 also refers to ”straw" or "hay"." Since straw or hay is never well organized, so 草 also has the meaning of "messy." So in English we say "draft" when referring to something we've written up quickly that needs editing. In Chinese they say 草稿 [cǎo gǎo], "straw draft." Similarly, there is the set phrase 草草了事 [cǎo cǎo liǎo shì], literally "straw straw finish matter" - "put it together like a pile of straw."
草书 [cǎo shū], "writings like grass," is the cursive style of Chinese calligraphy. That's what happens when a calligrapher writes, with his brush, very quickly and almost abstractly. This kind of calligraphy known for free expression of the artist's emotions. Below is a segment of a work done by Huai Su, who was a Buddhist monk of the Tang Dynasty known for his cursive-style calligraphy. The piece is part of Huai Su's autobiographical essay, which begins with "Huai Su's hometown is Changsha ..." Characters in cursive writings are hard to decipher, even for natively educated Chinese, so they're more like paintings, to be appreciated visually.