Orchids... pictures of different types of orchid flowers

A yellow orchid

Orchids are easily distinguished, as they share some very evident apomorphies. Among these: bilaterally symmetric (zygomorphic) and resupinate, a petal(labellum) is always highly modified, stamens and carpels are fused, and the seeds are extremely small.

Cattleya aclandiae.

as per wiki, Orchidaceae are well known for the many structural variations in their flowers.
Some orchids have single flowers but most have a racemose inflorescence, sometimes with a large number of flowers. The flowering stem can be basal, that is produced from the base of the tuber, like in Cymbidium, apical, meaning it grows from the apex of the main stem, like in Cattleya, or axillary, from the leaf axil, as in Vanda.

As an apomorphy of the clade, orchid flowers are primitively zygomorphic (bilaterally symmetrical), although in some genera like Mormodes, Ludisia, Macodes this kind of symmetry may be difficut to notice.