Leaf
A leaf (plural leaves or foliage) was a key organ in the anatomy of plants and trees; specialized for photosynthesis. Leaves of grass were known as blades.

T'Pol determined that as of 2151, the soil and foliage in the region of Terra Nova where the Novans lived was going to remain irradiated for a minimum of decade as a result of the fallout from an asteroid impact in 2083. () 

In 2152, while experiencing the Crossing,  relived picking up leaves with his father when he was eight or nine years old. ()

The leaves of the singing plant vibrated in the near constant winds on the planet's surface, the singing plant emitted a beautiful, wailing chime, which was very pleasing to the ear. Holding the plant's leaf still in one's hands would cause the song to cease, but it would resume again once let go, as was discovered by Spock, during his visit to the planet Talos IV in 2254. ()
 

In 2266, after being stopped by Balok's cube, all of the decks of the  reported green. James T. Kirk dismissed his dietary salad as "green leaves". ()

While speaking of her "spells" used to "keep"  in 2268, Nona showed him a leaf, asking him if he remembered it. He recalled the "night of madness" that the leaf caused and how it "brought up evil beasts from my soul." She then proceeded to rub the leaf on his arm, scratching him with it, leaving residual pieces of it stuck to his arm. ()

During the  initial scan of the planet  in 2285, Saavik noted sector one contained "foliage in fully developed state of growth." ()

Upon Worf's arrival to Carraya IV, he noted that the jungle foliage was "very dense", and due to this, it would take him twelve hours to reach the Romulan camp. ()

In 2373, Jadzia Dax compared the Jem'Hadars' tracking of the cloaked  through the Badlands by the ionization of its warp engines to the passage of a Ligorian mastodon through the forest: it could not be seen, but it made the leaves rustle. ()

One of the songs that The Doctor sang with Harry Kim and the Kimtones for the Qomar in 2375 was called "That Old Black Magic". The song's lyrics contained a reference to the feeling the singer had: "Round and round I go, Like a leaf that's caught in the tide." ()

Foods and beverages 
Some leaves were consumed as a food, such as by herbivores, and also used as the primary ingredient for salads.

 Lettuce 
 Rama leaf
 Red leaf tea
 Sea foliage
 Spinach
 Stuffed Cardaway leaf
 Tea
 Vulcan root leaf

See also 
 Laurel
 Leaf miner
 Manta leaf
 Palm Leaf of Axanar Peace Mission

External link 
 

Anatomy
Botany