The thickened or [[bulb]]-form stems of certain [[orchid]]s, the part being solid and borne above ground.{{SCH}}
It applies to the orchid family ([[Orchidaceae]]), specifically certain groups of [[epiphyte|epiphytic]] orchids, and may be single or composed of several internodes with evergreen or deciduous leaves along its length.
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In some species, it is hardly swollen at all and looks like a normal stem with many leaves while at the other extreme, some genera such as ''[[Bulbophyllum]]'' have single, spherical pseudobulbs with one leaf at the apex of each.
Whether cane-like (with many joints) or spherical (with one or few joints), they are all produced from a long lived creeping stem called a rhizome which may itself be climbing or pendulous.
The pseudobulbs are themselves relatively short lived (1-5 years), but are continually produced from the growing tip of the rhizome.
The other growth habit used by [[tropical]] [[epiphyte|epiphytic]] orchids is known as [[monopodial]].
