Starfleet Academy grounds with paved paths surrounded by grass
Grasses were a diverse group of plants from Earth, which included the grains. Grass-like plants were also found on many other planets. Grass that was cut, dried, and used for animal feed was called hay.
A Kikuyu proverb said "when elephants fight, it's the grass that suffers." (SNW: "Strange New Worlds")
Malcolm Reed was allergic to tropical grasses. (ENT: "Silent Enemy")
The Xyrillians grew grass on the floors of their starships. Charles Tucker III once noted the gasses they emitted helped the Xyrillians' metabolism, and smelled like a "freshly mowed lawn." (ENT: "Unexpected")
Grass was found on Pahvo, which like all vegetation on the planet vibrated with a particular tone. (DIS: "Si Vis Pacem, Para Bellum")
Real grass was prepared for the Human exhibit at the Lactra VII zoo. (TAS: "The Eye of the Beholder")
Cadet Wesley Crusher stated that when Boothby took him on a tour of the grounds of Starfleet Academy, he showed him practically every single blade of grass. (TNG: "The Game")
Annorax was eager to perform another temporal incursion, though the Krenim Imperium regained its strength at 98%. He wouldn't rest until every colony, every individual, and every blade of grass had been restored. (VOY: "Year of Hell")