× Oncostele

× Oncostele, abbreviated Ons., is a hybrid genus of orchids, used for greges containing at least one ancestor species from the genera Oncidium (Onc.) and Rhynchostele (Rst.). The nothogenus was defined in 2003 by J. M. H. Shaw.

Greges
Over 500 greges have been registered in × Oncostele. The grex Midnight Miracles has two cultivars, 'Masai Red' and 'Masai Splash', that have gained the Royal Horticultural Society's Award of Garden Merit.

Primary
The genus × Oncostele contains the following primary hybrids:
 * Ons. Black Beauty, Santa Barbara (1988) = Rst. bictoniense × Onc. leucochilum
 * Ons. Elske Stolze, L.Stolze (1978) = Onc. sotoanum × Rst. bictoniensis (basionym: Odontocidium)
 * Ons. Feathers, Woodland (2006) = Onc. maculatum × Rst. rossii
 * Ons. Rustic Bridge, Rod McLellan Co. (1981) = Onc. fuscatum × Rst. ureskinneri

Non-primary

 * Ons. Wildcat = Ons. Rustic Bridge × Onc. Crowborough, which has gained the Royal Horticultural Society's Award of Garden Merit.

Formerly

 * Cus. Compadre Juan Manzur, S.Cusi (2007) = Cauc. phalaenopsis (syn. Onc. phalaenopsis) × Rst. rossii