古典詩歌中，自然界的花草樹木常因為生長特質、外型特徵或隨四紀榮枯的形象特徵而成為文人筆下頌詠比興的題材，即使是不起眼的「草」類植物也別具意趣，自然環境中無論是欣欣向榮的「春草」、「芳草」、「燕草」、「碧草」;或是枯黃乾萎的「秋草」、「衰草」;或是蔓衍叢生的「惡草」;或是被階腹地的「庭草」;或是望風而靡的「偃草」;或是迎風經霜的「勁草」;或是綿延無盡的「邊草」，都成為騷人墨客以多情心眼觀景體物下的審美經驗與意象創造，在承襲古意、輾轉沿用語闢徑創新之後，積澱出生機勃發、靜謐幽寂、政治教化等譬喻或象徵，或是離愁別恨、懷遠思歸、韶光流轉、人事變遷等喟嘆。檢索唐代之前的詩歌，可發現草意象的類型與意涵已十分豐富，自先秦以迄隨代，在寫景之外，藉草來興發感時傷逝之悲，或是抒寫離愁別緒與懷遠思鄉之情的手法已然漸趨成熟。

In classical poetry, flowers, grass, and trees in nature tend to be the materials used literati due to their exterior features or their image characteristics, such as their ups and downs with the four seasons. Even the plant as plain as "grass" also have their uniquo charm. No matter the "spring grass," "fragrant grass," "flourishing grass," and "green grass" which stand for blossoming, the "autumn grass" and "withered grass" which stand for withered and yellow, the "weeds" which grow in lumps, the "garden grass" which cover the groud, the "bending grass" which bend as wind blows, the "strong grass" which tolerate the wind and frost, or the endless "grass on the border," they all become the aesthetic experiences or image creations expressed by literati through their sensitive and sentimental observations. Metaphors or symbols, such as vibrant vitality, serenity and seclusion, and political indoctrination or exclamation for grief of parting, the think of returning home, the change of time, and vicissitudes of human affairs were used in poetry after the literati inherited, adopted, and reformed the traditional poetry. In addition, before the heyday of poetry in the Tang Dynasty,abundant and unique implications of objects had been interpreted.