Houlletia is a genus of large-growing epiphytic orchids native to Mexico, and possibly also Guatemala through Central America to Bolivia.

The inflorescences begin from the base of the pseudobulbs and are always pendant, with fleshy, showy flowers hanging downward ("nodding") on a simple raceme.

[1] In 1999, E. Luckel & H. Fessel published the new genus Jennyella "to accommodate the globose, white flowered taxa."

The other group, containing H. sanderi, H. wallisii and H. lowiana, has globose, nonresupinate white to yellow flowers, mostly unspotted, and borne on an erect inflorescence.

[1] As of December 2023[update], Plants of the World Online accepted the following species:[3] They are found growing epiphytically and terrestrially on embankments in cool, humid, wet areas, 1,000-2,200 m elevation.