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Morphology |
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Columnea
is readily distinguishable from other Gesneriaceae based on its morphology,
but generally from a combination of traits rather than any single
character. For any individual "rule", there are exceptions. |
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That said, the genus can generally be defined by the presence of a fleshy indehiscent fruit containing many seeds (a berry) that is neither translucent nor orange (right). The presence of a berry and a habit that is vining or epiphytic (as opposed to shrubby) is generally sufficient to recognize a species of Columnea. Additionally, most species of Columnea have a bilaterally symmetric corolla that is long-tubular and with either a very short limb (part of corolla that is not fused into a tube) or are strongly bilaterally symmetric. |
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Also distinctive are species of section Columnea with their large and strongly bilaterally symmetric flowers (right). Species of section Collandra are also distinctive: leaves are opposite, but so different in size that the smaller leaf almost goes unnoticed (anisophylly) and the large leaves grow in a single plane creating what the late Dr. Wiehler referred to as a "fern-frond" habit. |
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Species of sections Stygnanthe and many species of section Ortholoma have smaller corollas that are only slightly bilaterally symmetric (right). However, these species also have stems with a horizontal or hanging orientation rather than growing erect and this makes them readily distinguishable from other New World Gesneriaceae. |
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Many species of section Ortholoma have appendages between the free corolla lobes that is unique among Gesneriaceae (right). Lastly species of section Pentadenia are generally erect in habit, often resembling species of Alloplectus, Glossoloma, or Crantzia. In general, the flowers of section Pentadenia are enlarged toward the middle of the corolla tube whereas many of the corollas of these other genera are widest at the opening. |
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