Fenestration is a term in botany

Botany

Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...

 that refers to natural holes in the leaves

Leaves

-History:Vocalist Arnar Gudjonsson was formerly the guitarist with Mower, and he was joined by Hallur Hallsson , Arnar Ólafsson , Bjarni Grímsson , and Andri Ásgrímsson . Late in 2001 they played with Emiliana Torrini and drew early praise from the New York Times...

 of some species of plants. The size, shape, and quantity of holes in each leaf can vary greatly depending on the species and can even vary greatly within a given species. Fenestration is caused by sections of leaf ceasing cell growth or by dying during an early stage in the development of the leaf. These deformations that are created earliest in the leaf development end up looking more like slashes whereas those that develop earlier end up looking more like holes. This trait is found in only one species in Aponogetonaceae

Aponogetonaceae

The Aponogetonaceae are a family of flowering plants in the order Alismatales.In recent decades the family has had universal recognition by taxonomists. The APG system and APG II system treat it in the order Alismatales in the clade monocots...

 and a few genera in Araceae

Araceae

Araceae are a family of monocotyledonous flowering plants in which flowers are borne on a type of inflorescence called a spadix. The spadix is usually accompanied by, and sometimes partially enclosed in, a spathe or leaf-like bract. Also known as the Arum family, members are often colloquially...

.

Its not fully known what evolutionary purpose fenestration serves, but there are several possibilities. Fenestration could serve the purpose of reducing the chances of leaves tearing in high winds or it could help to maximize the amount of rain that's able to reach the plant's roots. Another possibility is that they help to cool the plant by producing turbulence around the leaf.

The term is also used to describe plants with holes in their trunks, such as Platypodium elegans

Platypodium elegans

Platypodium elegans or the graceful platypodium is a large leguminous tree found in the Neotropics that forms part of the forest canopy. It was first described by Julius Rudolph Theodor Vogel in 1837 and is the type species of the genus. The tree has been known to grow up to 30 metres in...

which can be mistaken for a strangler fig

Strangler Fig

Strangler fig is the common name for a number of tropical and subtropical plant species, including some banyans and unrelated vines, including among many other species:* Ficus aurea, also known as the Florida Strangler Fig...

.