Clark, J. L. 2004. A monograph of Alloplectus (Gesneriaceae). Selbyana 25: 182-209.

_________. and E. A. Zimmer. 2003. A preliminary phylogeny of Alloplectus (Gesneriaceae): implications for the evolution of flower resupination. Syst. Bot. 28: 365-375.

_________, P. S. Herendeen, L. E. Skog, and E. A. Zimmer. 2006. Phylogenetic relationships and generic boundaries in the tribe Episcieae (Gesneriaceae) inferred from nuclear, chloroplast, and morphological data. Taxon 55: 313-336.

Fritze, K. J. and N. H. Williams. 1988. The taxonomic significance of pollen morphology in the Columnea alliance (Gesneridaceae: Gesnerioideae). Ann. Missouri Bot. Gard. 75: 168-191.

Hanstein, J. 1865. Die Gesneriaceen des Koniglichen Herbariums und der Garten zu Berlin, nebst Beobachtungen uber die Familie im Ganzen. II, 3. Linneae 34: 225-462.

Hooker, J. D. 1844. Trichanthe minor. Hook. Icon. Pl. 3: pl. 666.

Jones, C. E. and P. V. Rich 1972. Ornithophily and extrafloral color patterns in Columnea florida (Morton) Morton (Gesneriaceae). Bull. S. Calif. Acad. Sci. 7: 220-243.

Kvist, L. P. and L. E. Skog. 1993. The genus Columnea (Gesneriaceae) in Ecuador. Allertonia 6: 327-400.

Morley, B. D. 1971. A hybrid swarm between two hummingbird-pollinated species of Columnea (Gesneriaceae) in Jamaica. J. Linn. Soc. Bot. 64: 81-96.

_________. 1974. Notes on some critical characters in Columnea classification. Ann. Missouri Bot. Gard. 61: 514-525.

_________. 1976a. A key, typification and synonymy of the sections in the genus Columnea L. (Gesneriaceae). Contr. Nat. Bot. Gard., Glasnevin. 1: 1-11.

_________. 1976b. Hybridization studies in Columnea L. (Gesneriaceae). 1. Jamaican species. Bot. J. Linn. Soc. 72: 191-198.

Oersted, A. S. 1858. Centralamerikas Gesneraceer, et systematisk, plantegeographisk Bidrag til Centralamerikas Flora. 78 pp. 11 pls. Copenhagen. Reprinted in 1861 in Kongel. Danske. Vidensk.-Selsk. Skr. 5(5): 75-152, t. 1-11. Copenhagen.

Schulte, L. J., J. L. Clark, S. J. Novak, S. K,. Jeffries, and J. F. Smith. 2015. Speciation within Columnea section Angustiflorae (Gesneriaceae): Islands, pollinators and climate. Molec. Phylog. Evol. 84: 125-144.

_________, J. L. Clark, S. J. Novak, M. T.-Y. Ooi, and J. F. Smith. 2014. Paraphyly of Section Stygnanthe (Columnea, Gesneriaceae), a New Section Inferred from ITS and Chloroplast DNA Data, and a Revision of the Species of Section Angustiflorae Syst. Bot. 39: 613-636.

Sherk, L. C. and R. E. Lee. 1967. Interspecific hybridization in the genus Columnea (Gesneriaceae). Baileya 15: 89-96.

Skog, L. E. 1978. Flora of Panama Part IX. Family 175. Gesneriaceae. Ann. Missouri Bot. Gard. 65: 783-998.

Smith, J. F. 2000. Phylogenetic resolution within the tribe Episcieae (Gesneriaceae): congruence of ITS and ndhF sequences from parsimony and maximum-likelihood analyses. Amer. J. Bot. 87: 883-897.

_________. 1996. Tribal relationships within the Gesneriaceae: a cladistic analysis of morphological data. Syst. Bot. 21: 497-514.

_________. 1994. Systematics of Columnea sections Pentadenia and Stygnanthe (Gesneriaceae). Syst. Bot. Monogr. 44: 1-89.

_________. 1991. The Evolution and Systematics of Columnea. Ph. D. Dissertation, University of Wisconsin-Madison.

_________ and C. L. Carroll. 1997. Phylogenetic relationships of the Episcieae (Gesneriaceae) based on ndhF sequences. Syst. Bot. 22: 713-724.

_________ and K. J. Sytsma. 1994a. Evolution in the Andean epiphytic genus Columnea (Gesneriaceae). Part I. Morphology. Syst. Bot. 19: 220-235.

_________ and __________. 1994b. Evolution in the Andean epiphytic genus Columnea (Gesneriaceae). Part II. Chloroplast DNA restriction site variation. Syst. Bot. 19: 317-336.

_________ and __________. 1994c. Molecules and morphology: Congruence of data in Columnea (Gesneriaceae). Pl. Syst. Evol. 193: 37-52.

_________, M. T. Ooi, L. Schulte, M. Amaya-Marquez, and J. L. Clark. 2013. Searching for monophyly in the subgeneric classification systems of Columnea (Gesneriaceae). Selbyana 31: 126-142.

_________, J. L. Clark, M. Amaya-Márquez, and O. H. Marín-Gómez. 2017. Resolving incongruence: Species of hybrid origin in Columnea (Gesneriaceae). Molec. Phylog. Evol. 106: 228-240.

Weber, A. 2004. Gesneriaceae. pp. 63-158 In: The families and genera of vascular plants. Vol. 7. Dicotyledons. Lamiales (except Acanthaceae incl. Avicenniaceae). K. Kubitzki (ed.) Berlin: Springer.

Weinstein, B. G. and C. H. Graham, 2017. Persistent bill and corolla matching despite shifting temporal resources in tropical hummingbird-plant interactions. Ecology Letters 20: 1461-0248

Wiehler, H. 1973. One hundred transfers from Alloplectus and Columnea (Gesneriaceae). Phytologia 27: 309-328.

_________. 1983. A synopsis of the neotropical Gesneriaceae. Selbyana 6: 1-249.

Williams, N. H. 1978. Pollen structure and the systematics of the neotropical Gesneriaceae. Selbyana 2: 310-322.

Zimmer, E. A., E. H. Roalson, L. E. Skog, J. K. Boggan, and A. Indurm. 2002. Phylogenetic relationships in the Gesnerioideae (Gesneriaceae) based on nrDNA ITS and cpDNA trnL-F and trnE-T spacer region sequences. Amer. J. Bot. 89: 296-311.