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Columnea bivalvis (Gesneriaceae) a new species from the eastern slopes of the Ecuadorian Andes


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Recent field expeditions to the eastern slopes of the Ecuadorian Andes and revisionary work on Columnea (Gesneriaceae) section Collandra have resulted in the discovery of a new plant species. The new species, Columnea bivalvis, is distinguished by the presence of two pendent clasping bracts that enclose a single axillary flower.
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J. Bot. Res. Inst. Texas 5(1): 75 – 79. 2011
Marisol Amaya-Márquez* John L. Clark
Instituto de Ciencias Naturales Department of Biological Sciences
Universidad Nacional de Colombia Box 870345
Apartado 7495, Bogotá, COLOMBIA The University of Alabama Tuscaloosa, Alabama 35487, U.S.A.
*Corresponding author
Recent f ield exped itions to the e astern slope s of the Ecuador ian Andes a nd revisio nary work on Columnea (Gesneri aceae) section C ollandra
have resulted in t he discovery of a new plant species. The new species, Columnea bivalvis, is dist inguished by the presence of t wo
pendent clasping bracts that enclose a single axillary flower.
Expediciones recientes a las estribaciones orientales de los A ndes Ecuatorianos, y el trabajo de revisión de la sección Collandra del gé-
nero Columnea (Gesneriaceae) perm itieron el descubrimiento de una nueva especie de planta. La nueva es pecie, Columnea bivalv is, se
distingue por tener dos brácteas colgantes que se tocan por su s márgene s encerrando una única flor axil ar.
key worDs: Collandra, Columnea, Gesneriaceae, Ecuador, Taxonomy, Flora of Ecuador
The genus Columnea belongs to the New World subfamily Gesnerioideae. It is the most diverse genus in
the subfamily with over 200 species (Skog & Boggan 2006; Weber 2004; Burtt &Wiehler 1995). The sub-
division of Columnea sensu lato into sections or into segregate genera has caused much controversy and
taxonomic confusion (Kvist & Skog 1993; Wiehler 1973, 1983). We recognize the classification based on
recent phylogenetic hypotheses that strongly support the monophyly of Columnea (Smith 1994; Smith &
Sytsma 1994; Clark et al. 2006) and non-monophyly for segregate genera. Thus, the sectional classification
outlined in Kvist and Skog (1993) is more desirable as an informal classification until segregate clades can
be evaluated phylogenetically.
The new specie s described here belongs to Collandra, the most diverse section in Columnea. The following
characters are useful for recognizing the species within this section: dorsiventral shoots with anisophyllous
subsessile leaves and ovoid (non-globose) berries. In this paper we describe a new species of Columnea that
is known from two populations between 1800 and 2350 m from the eastern slopes of the Ecuadorian Andes.
taxonomiC treatment
Columnea bivalvis J.L. Clark & M. Amaya, sp. nov. (Figs. 1 & 2). type: ECUADOR. tungurahua. Cantón Baños: par-
roquia Río Verde, sector Machay, forested trail (from Baños-Puyo road) towards Cascada de San Miguel via San Augustin, 1°23'5"
S, 78°16'50"W, 1800–2200 m, 23 Dec 2000, J.L. Clark, E. Narvaez & J. Vargas 5693 (holotype: US; isotypes: COL, MO, NY, QCA,
Differ t a ceteris Columnei s praes entia unius floris ax illaris inclusi in bin is bracteis amplectentibus by t he presence of a single axillary
flower enclosed by a pair of pendent clasping bracts.
Epiphytic vine, suffrutescent, often branched; stem terete, 0.3– 0.8 cm, reddish villous (trichomes 7–10
celled), internodes 1–4 cm long. Leaves opposite, strongly anisophyllous in a pair, chartaceous; larger leaf
with petioles 0.3–0.9 cm long, densely reddish villous; blade asymmetrical, narrow oblong to oblanceolate,
9.5–20 × 2.2–4.2 cm, base oblique, apex acumin ate, margin dentate; adaxi ally green, golden vi llous (trichomes
5–7 celled) and with sparsely distributed white unicellular setulose hairs, veins not prominent; abaxially
76 Journal of the Botanical Research Institute of Texas 5(1)
Fig. 1. Columnea bivalvis. A. Habit and inflorescence. B. Enlargment of larger leaf margin. C. Calyx and gynoecium. D. Corolla and androecium. E. Fruit.
F. Seed.
Amaya and Clark, Columnea bivalvis, a new species from Ecuador 77
Fig. 2. Columnea bivalvis. A. One of the paired bracts removed to show uniformly yellow tubular corolla. B. Dorsiventral shoot showing pendent bracts
(photos by J.L. Clark; from the live plant from which the holotype was collected, J.L. Clark, E. Narvaez & J. Vargas 5693).
78 Journal of the Botanical Research Institute of Texas 5(1)
green with red venation, villous (trichomes 5–7 celled), 8–10 pairs of lateral veins; smaller leaf sessile, blade
asymmetrical, oblong, 1.5–2 × 0.3–0.5 cm, base oblique, apex attenuate, margin dentate, adaxially green,
reddish villous (trichomes 7 celled), abaxially green, reddish villous (trichomes 7 celled). Inflorescence
epedunculate with 1 flower per node, larger bracts persistent and paired, green with red margins, outer
surface reddish villous, asymmetrical, broadly ovate, 4–4.7 × 2.5–3 cm, bracteoles 2–4, unequal in size,
narrowly ovate to lanceolate, 1.2–2.5 × 0.2–1 cm, pedicel 0.2–0.4 cm long, densely villous (trichomes 4–5
celled). Calyx pale green; lobes 5, nearly free joined only at the base by 1 mm of their length; narrow oblong,
1.5 × 0.3 cm, margin dentate with three glandular teeth on each side, outside densely villous (trichomes
5–7 celled), inside glabrous. Corolla uniformly yellow, tubular, 3.7–4.5 × 0.8–1 cm, basally gibbous and
slightly oblique in the calyx, gibbosity 0.4 × 0.5 cm constricted apically 0.3 cm, 0.8–1 cm at the widest
part of the tube and constricted again at the limb to 0.7 cm; limb nearly actinomorphic, slightly ampliate
in mid region, lobes rounded, subequal 0.3 × 0.3 cm, outside apically sericeous, glabrescent toward the
base (trichomes 8–12 celled), inside glabrous. Androecium of 4 stamens, filaments 3.2 cm long, glabrous,
basally connate for 0.5 cm; anthers oblong 2.0 × 1.3 mm, connective rectangular, 1.8 × 1.2 mm. Nectary a
single dorsal trilobed gland. Gynoecium with the ovary ovoid, 0.7 × 0.3 cm, densely sericeous; style 2.5–3
cm long, laminar with glandular trichomes; stigma bilobed. Fruit an ovoid berry, 1.5 × 0.8 cm. Seeds light
brown 1.8 × 0.5 mm, elliptic, and longitudinally striate.
Distribution and habitat.—Columnea bivalvis is only known from two localities in the wet Andean cloud
forests in eastern Ecuador between 1800 and 2350 m.
Phenology.—Flowers and fruits collected in April and December.
Columnea bivalvis is unique among the species of Columnea by having a pair of large pendent bracts that
enclose a single axillary flower (Figs. 1–2). The yellow tubular flowers are almost completely enclosed by the
bracts with only the throat extending beyond the bract margins. The bracts in C. bivalvis are superficially
similar to the Drymonia hoppii and D. affinis. Although large bracts are common in many Columnea species
and especially those belonging to the section Collandra, no species is known to have large pendent bracts
and dorsiventral shoots.
Columnea bivalvis is similar to C . medicinalis, C. albiflora, and C.eubracteata. The latter three species differ
by the presence of congested bracts compared to a pair of large pendent bracts (i.e., non-congested) in C.
bivalvis, and by the prominent bilabiate corolla limbs compared to a nearly actinomorphic corolla limb in
C. bivalvis.
Etymology.—The new species is named in reference to the marine and freshwater mollusca belonging to
the class Bivalvia because of the resemblance to the two large rounded bracts that enclose a single axillary
paraty pe: ECUADOR. Napo: Km 40 from El Carmelo on road towards La Bonit a, near 5 km below La Alegría, 0°35'N, 77°30'W, 2350
m, 8 Apr 1979, B. Lojtnant et al. 11930 (NY).
We thank the Herbario Nacional Colombia (COL), the Smithsonian Institution’s National Museum of Natural
History – Department of Botany (US), and the Herbario Nacional del Ecuador (QCNE) for access to their
collections. We thank Laurence E. Skog (US) for his willingness to collaborate on the revision of Collandra.
Funding for M AM came from The Gesneriad Society’s Elv in McDonald Research Endowment Fund. Funding
for JLC came from the National Science Foundation (DEB-0841958 & DEB-0949169). We also thank Juan
Carlos Pinzón for the illustration and Pedro Ortiz for help in selecting an appropriate specific epithet and
the Latin description. We thank John R. Clark and Harry Luther for providing helpful comments to an early
version of the manuscript.
buRTT, B.L. anD H. wiehleR. 1995. Classification of the family Gesneriaceae. Gesneriana 1:1–4.
Amaya and Clark, Columnea bivalvis, a new species from Ecuador 79
claRK, J.L., P.S. heRenDeen, L.E. sKog, anD E.A. zimmeR. 2006. Phylogenetic relationships and generic boundaries in
the Episcieae (Gesneriaceae) inferred from nuclear, chloroplast, and morphological data. Taxon 55:313–336.
KVisT, L.P. anD L.E. sKog. 1993. The genus Columnea (Gesneriaceae) in Ecuador. Allertonia 6:327–400.
sKog, L.E. anD J.K. boggan. 2006. A new classification of the Western Hemisphere Gesneriaceae. Gesneriads 56:12–17.
smiTh, J.F. 1994. Systematics of Columnea section Pentadenia and section Stygnanthe (Gesneriaceae). Syst. Bot.
Monogr. 44:1–89.
smiTh, J.F. anD K.J. syTsma. 1994. Molecules and morphology: congruence of data in Columnea (Gesneriaceae). Pl.
Syst. Evol. 193: 37–52.
webeR, A. 2004. Gesneriaceae. In: Kubitzki, K. and J.W. Kadereit, eds. The families and genera of vascular plants.
Vol. 7. Flowering plants, dicotyledons: Lamiales (except Acanthaceae including Avicenniaceae). Berlin &
Heidelberg, Germany: Springer-Verlag. Pp. 63–158.
wiehleR, H. 1973. One hundred transfers from Alloplectus and Columnea (Gesneriaceae). Phytologia 27:309–329.
wiehleR, H. 1983. A synopsis of the neotropical Gesneriaceae. Selbyana 6:1–219.
... & Hook (Columnea L., Gesneriaceae) has revealed that our knowledge about this linage of plants is far from complete. Several new species of Columnea, most of them from Colombia, have been published in the last ten years (e.g., Amaya-Márquez et al. 2004; Kriebel 2005; Amaya-Márquez 2010a, b; Amaya-Márquez & Clark 2011; AmayaMárquez & Marín-Gómez 2012; AmayaMárquez & Smith 2012; Clark & Clavijo 2012). The species of the genus Columnea play an important role in maintaining biodiversity due to the specialized system of pollination by hummingbirds (Morley 1971; Jones & Rich 1972; Stiles & Freeman 1993; Amaya-Márquez 1996; Kastinger & Weber 2000). ...
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Two new species of Columnea belonging to section Collandra (Gesneriaceae) from the "cordillera Occidental" in the Colombian Andes are described and illustrated. Columnea caudata is distributed along the Biogeographical Chocó in the Departments of Antioquia, Chocó, Risaralda, and Valle del Cauca, whereas Columnea megafolia is restricted to Antioquia, and probably is an endemic species of the National Natural Park Las Orquídeas.
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A new species of Columnea belonging to section Ortholoma (Gesneriaceae) from Antioquia Department in Colombia (Cordillera Occidental) is described and illustrated. This species is the second one known in Columnea to have a corolla with 4 external appendages; the first one described with this trait was C. paraguensis. This trait adds to the knowledge on the diversity of corolla architecture in Columnea, and points out an effect of pollinators on the diversification process in this plant lineage.
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Episcieae is the most diverse tribe of Gesneriaceae, with 22 genera and over 700 species, or roughly 21% of all Gesneriaceae. The tribe is restricted to the Neotropics and is characterized by axillary flowers derived from a pair-flowered cyme inflorescence by reduction, a three-trace trilacunar node with split lateral bundles, superior ovaries, and with most members having a haploid chromosome number of n = 9 [n = 8 in Codonanthe and Nematanthus]. Most traditionally recognized genera in Episcieae are either known to be non-monophyletic or have not been represented adequately in phylogenetic analyses to test their monophyly. This paper presents phylogenetic analyses utilizing two molecular [the internal transcribed spacer region of 18S-26S nuclear ribosomal DNA (ITS) and the trnH-psbA intergenic spacer for 155 species] and one morphological (99 characters for 120 species) datasets, combined in a total evidence analysis. All traditionally recognized genera of Episcieae except for the monotypic genus Lampadaria are represented. Of the 21 sampled genera in Episcieae, 16 are represented by the generic type species. The genera Glossoloma and Crantzia are segregated from the genus Alloplectus as traditionally recognized. Other genera that are strongly supported as monophyletic include Alsobia, Columnea (with the inclusion of C. dielsii), Corytoplectus, and Episcia. Drymonia is weakly supported and is shown here to be morphologically diverse and in need of further evaluation. Evolution of fruit structure is examined in the context of the phylogenetic results presented here with two previously unreported features that are here referred to as capsules with tardily dehiscent and non-dehiscent endocarps. Three independent origins of resupinate flowers are inferred for Glossoloma, Nematanthus, and Crantzia. Strongly supported clades have centers of diversity in southeastern Brazil (Nematanthus, Codonanthe, Codonanthopsis, and Paradrymonia anisophylla), northern South America (Alloplectus, Drymonia, Columnea, Neomortonia), Central America (Alsobia, Oerstedina, Rufodorsia, Cobananthus), and two clades with diversity in the Guiana Shield [(Paradrymonia, Nautilocalyx, Chrysothemis) and (Lembocarpus, Cremersia, Rhoogeton)]. Neomortonia, a genus of three species, is poorly supported due to conflict among datasets.
Perennial or rarely annual herbs, subshrubs, shrubs or rarely small trees; perennial herbs with fibrous roots or with rooting above- or underground stems, rootstocks, rhizomes, scaly rhizomes, or tubers; terrestrial, epiphytic or climbing. Stem erect, ascending, decumbent, creeping, pendulous, or ± absent. Leaves opposite, sometimes in whorls of three or four, or in near-distichous or spiral-alternate arrangement; usually petiolate; stipules absent; lamina usually undivided, rarely lobed or pinnately dissected. Number of leaf pairs sometimes reduced to the cotyledonary pair, with one of the two cotyledons growing up to a large, foliar organ. Indumentum of stem and leaves of glandular and eglandular hairs, rarely absent. Inflorescences a foliose or (rarely) bracteose indeterminate thyrse with axillary pair-flowered cymes; cymes sometimes reduced to solitary flowers; bracteolate or rarely ebracteolate. Flowers usually showy, zoophilous, rarely auto- or cleistogamous, 5- (rarely 4-)merous.
The 27 species of Columnea (Gesneriaceae) here described are assigned to sections Pentadenia and Stygnanthe. They are herbaceous perennials, occurring from southern Mexico to Bolivia from near sea level to 3800 m. In addition to morphology, geographic distribution, breeding systems, and phylogeny are discussed. The taxonomy is based on cladistic analyses of morphological diversity and chloroplast DNA restriction site variation (details of the analyses are published elsewhere). Section Pentadenia, previously monotypic, now comprises 9 species of suffrutescent robust herbs with isophyllous to slightly anisophyllous leaves, long pedicels, and conspicuous, strongly ventricose corollas. Section Stygnanthe, also newly circumscribed, includes 18 species of creeping, pendent, or upright herbs with isophyllous to anisophyllous leaves, short pedicels, and generally small, inconspicuous, and only slightly ventricose corollas. Three new combinations are proposed in sect. Stygnanthe: Columnea antiocana, C. fritschii, and C. rileyi.
A key to the 10 species of Cremosperma occurring in Ecuador is presented, including four new species that are described: C. ecuadoranum, C. humidum, C. muscicola and C. reldioides. A new variety is C. hirsutissimum var. glabrum. Cremosperma demissum and C. album, originally described from Ecuador and Colombia, respectively, are reduced to C. hirsutissimum var. demissum and C. hirsutissimum var. album. Cremosperma pusillum var. ecuadorense is transferred to C. hirsutissimum var. hirsutissimum. The distribution of Cremosperma is discussed.
The cladistic analysis and comparison of molecular and morphological data has been the source of much recent debate. In this study, independent analyses of molecular and morphological data fromColumnea L. sects.Pentadenia andStygnanthe (Gesneriaceae) are compared. Comparative methods include consensus, visually comparing trees from independent analyses and combined data analysis. Consensus methods provided little resolution. Comparison of trees obtained from the independent analyses revealed some differences although the trees are highly similar. However, a combined analysis found that the level of incongruence between the two data sets was low. The tree resulting from the combined data has aspects of both the morphological and molecular trees despite the larger number of molecular characters. In addition, the combined data tree has greater resolution than either of the two data sets singly, indicating that the two types of data are congruent, and complementary to each other.
A new classification of the Western Hemisphere Gesneriaceae
  • L E Skog
  • J K Boggan
sKog, L.E. anD J.K. boggan. 2006. A new classification of the Western Hemisphere Gesneriaceae. Gesneriads 56:12–17.