Leaf window

For the botanical term meaning a leaf has holes like windows, see Fenestration (botany).

A flowering Fenestraria rhopalophylla, so named due to the translucent leaf window on the tips of its modified leaf.

Leaf window is a specialized leaf structure consisting of a translucent area where sunlight can enter into the interior surfaces of the plant's modified leaf where photosynthesis can occur. A leaf with such structures is known as a Fenestrated leaf. The translucent structure can appear as a large continuous patch, a variegated or reticulated region, or as numerous small spots. This structural adaptation is found in certain succulent plants native to arid climates, which allow much of the plant to remain beneath the soil surface where it is protected from desiccation of extreme winds and heat while optimizing the absorption of light by increasing the photosynthetic surface area. Carnivorous plants can also make use of fenestrations by growing traps (highly modified leaves) which use sunlight to lure and/or confuse insects and increase the effectiveness of the trap.

Many of the known species containing leaf window are native to South Africa and neighbouring countries.

Species

The leaf window of Lithops salicola has a mottled appearance to act as camouflage

Genus of plants with numerous species having leaf windows include:

• Cephalotus spp.
• Conophytum spp.
• Darlingtonia spp.
• Fenestraria spp.
• Frithia spp.
• Haworthia spp.
• Lithops spp.
• Nepenthes spp.; known only from N. klossii and N. aristolochioides.
• Pleiospilos spp.
• Sarracenia spp.

Several other plant species have leaf windows:

• Bulbine haworthioides
• Bulbine mesembryanthemoides
• Peperomia columella
• Senecio rowleyanus

Plants with leaf windows are sometimes known as window plants, though this is also the common name used to refer to Fenestraria rhopalophylla.