Understanding the drivers of orchid diversification and rarity may prove crucial to their conservation. The Orchidaceae is characterised by the presence of mycorrhizal endophytes and a diversity of pollination syndromes (Rasmussen 1995, Jersakova et al. 2006). The prevalence of pollination by deceit and the spe- cialised mycorrhizal relationships in some taxa have been implicated in the diversification of the family (Cozzolino & Widmer 2005, Otero & Flanagan 2006). Furthermore, interactions with habitat speciali- sation may act in concert with these attributes to play a critical role in orchid diversification (Gravendeel et al. 2004). The influence of these factors in determin- ing intrinsic rarity in orchids remains poorly known. Understanding the drivers of orchid diversification and rarity may prove crucial to their conservation. The Orchidaceae is characterised by the presence of mycorrhizal endophytes and a diversity of pollination syndromes (Rasmussen 1995, Jersakova et al. 2006). The prevalence of pollination by deceit and the spe- cialised mycorrhizal relationships in some taxa have been implicated in the diversification of the family (Cozzolino & Widmer 2005, Otero & Flanagan 2006). Furthermore, interactions with habitat speciali- sation may act in concert with these attributes to play a critical role in orchid diversification (Gravendeel et al. 2004). The influence of these factors in determin- ing intrinsic rarity in orchids remains poorly known.