Full name and orig. publication: Columnea L., Sp. pl., ed 1: 638 (1 May 1753).
Etymology: Named after Fabio Colonna (Latin Fabius Columnus) (1567-1640), professor of botany in Naples. He was the first to depict plants by copper-plate illustrations.
Synonyms: Achimenes P.Browne (1756), non Pers. (1806), Dalbergaria Tussac (1811), Vireya Raf. (1814), Eusynetra Raf. (1837), Aponoa Raf. (1838), Glycanthes Raf. (1838), Trichantha Hook.f. (1844), Collandra Lem. (1847), Loboptera Colla (1849), Ortholoma (Benth.) Hanst. (1854), Pentadenia (Planch.) Hanst. (1854), Pterygoloma Hanst. (1854), Stenanthus Oerst. ex Hanst. (1854), Stygnanthe Hanst. (1854), Bucinella Wiehler (1977), nom. illeg., Bucinellina Wiehler (1981).
Infrafamilial position: Gesnerioid Gesneriaceae (Gesnerioideae) - Episcieae.
Description: Epiphytic herbs or shrubs (less commonly epipetric or terrestrial), shoots often conspicuously dorsiventral. Leaves opposite, base oblique, isophyllous or strongly anisophyllous, lower leaf surfaces often with a conspicuous pattern of red or purple toward the apex and/or along the margin and veins, rarely with translucent and red "windows" on the blade. Cymes axillary, in the anisophyllous species in the axils of the larger leaves only, epedunculate, 1- to 10-flowered, bracteoles often scale-like, less commonly large and hiding the calyces, frequently coloured. Sepals free nearly to the base, (sub)equal, entire or dissected. Corolla often red, less commonly yellow, cream or greenish, tube frequently ventricose, basally often dorsally gibbous, usually glandular hairy in throat, limb with subequal lobes to strongly bilabiate, lobes 5 or 4 (due to the fusion of two dorsal ones), usually rounded. Stamens 4, included or exserted, a minute staminode occasionally present; filaments usually basally fused and adnate to corolla tube; anthers often coherent. Nectary a single bilobed gland, less commonly 4 or 5, rarely 2 or 3 free glands. Ovary superior, glabrous or sericeous; style glabrous or pilose; stigma stomatomorphic or bilobed. Fruit a globose or ovoid berry.
Chromosome number: 2n = 18.
Species number: Over 270.
Species names (incl. publication and synonyms): See Skog, L.E. & J.K. Boggan. 2005: World checklist of Gesneriaceae: http://persoon.si.edu/Gesneriaceae/Checklist.
Type species: Columnea scandens L.
Distribution: Ranging from Mexico south to Ecuador and Bolivia and east to Brazil. Columnea s. l. is, besides Besleria, the largest genus in the neotropics. Particularly rich in species are Colombia, Ecuador and Panama, the diversity rising with increasing humidity and being highest in wet forests, pluvial forests and lower montane forests.
Ecology: Common epithytes on trees in lowland and montane forests.
Notes: Pollination is essentially by hummingbirds, which are attracted either by the large and brilliantly coloured flowers, or - when the flowers are rather inconspicuous - by purple markings or translucent "windows" on the underside of the leaves (cf. Jones & Rich 1972). Many species are in cultivation, representing magnificent green-house and (in warmer countries) outdoor ornamentals.
An ample discussion whether to split Columnea into separate genera or into sections is found in Wiehler (1983) and in Kvist & Skog (1993). In order to avoid that almost any berry-fruited species fits into the vague concept of Columnea s. l., Wiehler pleads for splitting the genus into the following five "columneoid genera": Columnea L. s. str., Dalbergaria Tussac, Pentadenia Hanst., Trichantha Hook., Bucinellina Wiehler (see there). As the genera are rather weakly delimited and there is some overlap, Kvist & Skog (l.c.) plead for a subdivision into sections.
In contrast to previous sectional classifications (e.g., Morley l.c.), which are essentally based on corolla characters and, therefore, are highly artificial, the sections recognized by Kvist & Skog (l.c.) are largely identical with the "columneoid" genera of Wiehler (1973). They read: (1) sect. Bucinellina (Wiehler) Kvist & Skog, (2) sect. Collandra (Lem.) Benth., (3) sect. Columnea, (4) sect. Ortholoma Benth., (5) sect. Pentadenia (Planch.) Benth., (6) sect. Stygnanthe (Hanst.) Benth. At sectional level the names Collandra and Ortholoma have priority over Dalbergaria and Trichantha, respectively. Apart from the ranking, a difference is that sect. Stygnanthe is split off from sect. Pentadenia.
Selected references: Stearn, Bull. Brit. Mus. Nat. Hist. (Bot.) 4: 181-236 (1969), reg. rev. (Jamaica); Morton, Phytologia 21: 165-195 (1971), reg. rev. (Panama); Jones & Rich, Bull. South Calif. Acad. Sci. 71: 113-116 (1972), ecol.; Morley, Contr. Nat. Bot. Gard. Glasnevin 1: 1-11 (1976), sections; Skog, Ann. Missouri Bot. Gard. 65: 838-888 (1979), reg. rev. (Panama); Wiehler, Selbyana 6: 187-189 (1983); Kvist & Skog, Allertonia 6: 327-400 (1993), reg. rev. (Ecuador); Smith, Syst. Bot. Monogr. 44: 1-89 (1994), sect. rev.; Smith & Sytsma, Syst. Bot. 19: 220-235 (1994), morph., evol.; Smith & Sytsma, Syst. Bot. 19: 317-336 (1994), restr. site analys.; Amaya-Márquez, M.Sci.Thesis Univ. Nacional Colombia (1995), pollination; Feuillet & Steyermark, Fl. Venezuel. Guayana 5 (1999), reg. rev.; Skog, Monogr. Syst. Bot. Missouri Bot. Gard. 85: 1114-1128 (2001), reg. rev. (Nicaragua); Amaya, Skog & Kvist, Edinburgh J. Bot.60: 414-424 (2004), new spp.
Bibliography: See Skog, L.E. & J.K. Boggan. 2005. Bibliography of the Gesneriaceae. 2nd edition: http://persoon.si.edu/Gesneriaceae/Bibliography.
Illustrations: See under Columnea s.str., Buccinellina, Dalbergaria, Pentadenia and Trichantha.
last modified: 2007-01-05