Pneumatode

[2] Plants with photosynthetic roots, such as epiphytic orchids like Dendrophylax lindenii also possess these structures.

[4] Fungal infections of plants may begin through penetration of the roots through pneumatodes.

[5] Pneumatodes are considered as a special type of cyclocytic stomata.

The pneumatodes may function as double structures for gas exchange and liquid water elimination (guttation).

[6] Leafless orchids with photosynthetic roots rely on the gas exchange through pneumatodes for photosynthesis.

Pneumatodes on roots of a Vanda orchid
Visualisation of pneumatodes on a root of Phalaenopsis philippinensis