Dancing Lady Orchids Take Center Stage

By Matthew C. Pace

Mar 17 2020

Dancing Lady Orchid is the collective common name for the orchid genus Oncidium and its relatives. The name refers to the colorful flowers that appear like dancers in billowing dresses.

In additon to being beautiful, Oncidium and its relatives are also extremely interesting and have a long and complictaed taxonomic history. In short, Oncidium was once used as the genus name for over 650 species spread across the Caribbean, Central America, and South America. However, new research using molecular tools and a reappraisal of morphology found that 'Oncidium' was actually composed of 11 distinct genera: Comparettia, Gomesa, Miltonia, Odontoglossum, Oncidium, Otoglossum, Nohawilliamsia, Psygmorchis, Tolumnia, Trichocentrum, and Vitekorchis. An analogy would be to say that humans, gorillas, chimpanzees, and orangutans were all a single genus!

Botanists discovered that these 11 genera, some of which are not particularly closely related, all converged on a similar floral shape to attract the same types of pollinators. Additionally, these orchids were converging on the flower shape of a unrelated group of tropcial shrubs, the Malpighiaceae. Evolution was driving these orchids to look like the shrubs because the shrubs produce nectar and oils to reward visiting pollinators, whereas the orchids do not provide any reward. In effect, the orchids are mimicking the shrub flowers to trick pollinators into visiting them instead, even though the orchids offer the pollinators nothing in return. This mimicry and convergence is so striking, that it caused humans to combine them all in one orchid genus.

The next time you see a vivid Oncidium or Comparettia at NYBG's famous Orchid Show, take a moment to think about these marvels of evolution in a whole new light.

Digitization of NYBG Steere Herbarium orchid specimens made possible through a National Science Foundation digitization grant (award #1802034).


Digitization TCN: Collaborative Research: Digitizing "endless forms": Facilitating Research on Imperiled Plants with Extreme Morphologies

Chase, M. W., N.H. Williams, A.D. de Faria, K.M. Neubig, M. do  Carmo E. Amaral, and W.M. Whitten. 2009. Floral convergence in Oncidiinae (Cymbidieae; Orchidaceae): an expanded concept of Gomesa and a new genus Nohawilliamsia. Annals of Botany. 104: 387–402. doi:10.1093/aob/mcp067

Givnish, T.J., D. Spalink, M. Ames, S.P. Lyon, S.J. Hunter, A. Zuluaga, W.J.D. Iles, M.A. Clements, M.T.K. Arroyo, J. Leebens-Mack, L. Endara, R. Kriebel, K.M. Neubig, W.M. Whitten, N.H. Williams, and K.M. Cameron. 2015. Orchid Phylogenomics and multiple drivers of their extraordinary diversity. Proceedings of The Royal Society B 282: doi.org/10.1098/rspb.2015.1553

Neubug, K.M., W.M. Whitten, N.H. Williams, M.A. Blanco, L. Endara, J. Gordon Burleigh, K. Silvera, J.C. Cushman, and M.W. Chase. 2012. Generic recircumscriptions of Oncidiinae (Orchidaceae: Cymbidieae) based on maximum likelihood analysis of combined DNA datasets. Botanical Journal of the Linnean Society 168: 117–146

Papadopulos, A.S.T., M.P. Powell, F. Pupulin, J. Warner, J.A. Hawkins, N. Salamin, L. Chittka, N.H. Williams, W.M. Whitten, D. Loader, L.M. Valente, M.W. Chase, and V. Savolainen. 2013. Convergent evolution of floral signals underlies the success of Neotropical orchids. Proceedings of The Royal Society B 280: doi.org/10.1098/rspb.2013.0960

Renner, S.S., and H. Schaefer. 2010. The evolution and loss of oil-offering flowers: new insights from dated phylogenies for angiosperms and bees. Philosophical Transactions of the Royal Society B 365: 423–435 doi.org/10.1098/rstb.2009.0229