Pseudobulb

As a pseudobulb (from Latin bulbus for " onion " ), a thickened portion of the stem axis sympodial orchids that grow is referred to in botany, which serves the plant as water and nutrient storage and thereby can be very different in its form (see figure below). Pseudobulbs can also form cavities in which in some species (eg Caularthron bilamellatum ) ants nest.

The term " pseudobulb " was first used in 1837 by Lindley.

Existence of the pseudobulbs of several internodes approximately uniformly thickened as in the genus Dendrobium, one speaks of homo blasts pseudobulbs. In addition to the thickening of its stem axis can be observed with pseudobulbs the tendency found in many orchids, leaves form no longer uniformly distributed over the entire length of the thickened shoot, but only in the upper part. Endpoint of this development are pseudobulbs, which consist essentially only of a single internode, at the head of 1-2 leaves sitting like many Bulbophyllum species. Pseudobulbs of this type are referred to, in contrast to the above hetero- emited pseudobulbs.