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Research Article
New circumscriptions add two northern Andean species to Kohleria (Gesneriaceae)
expand article infoJohn L. Clark, Lou Jost§
‡ The Lawrenceville School, Lawrenceville, United States of America
§ Fundacion EcoMinga, Baños, Ecuador
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Abstract

Recent studies of type specimens and exploratory research expeditions in the northern Andes have resulted in an updated circumscription and recognition for two species of Kohleria (Gesneriaceae) in Ecuador and Colombia. A change in the rank from a variety to species is recognized for Kohleria anisophylla (Fritsch) Wiehler. The combination Kohleria andina (Fritsch) J.L. Clark & Jost, comb. nov. is provided here and a lectotype is designated. The updated circumscriptions of these two species are supported by morphology and geographic distribution. The presence of an epiphytic habit for Kohleria is discussed. Field images based on recent expeditions are provided to support the circumscriptions presented here.

Resumen

Los estudios recientes de las colecciones tipo y las expediciones exploratorias en el norte de los Andes han dado como resultado la actualización en la circunscripción y reconocimiento de dos especies de Kohleria (Gesneriaceae) en Ecuador y Colombia. Se reconoce el cambio de rango de variedad a especie para Kohleria anisophylla (Fritsch) Wiehler. Se presenta la nueva combinación Kohleria andina (Fritsch) J.L. Clark & Jost, comb. nov. con la designación de su lectotipo. La circunscripción actualizada de estas dos especies está soportada por caracteres morfológicos y distribución geográfica. Se discute la presencia del hábito epífito en Kohleria. Se presentan imágenes obtenidas en las expediciones de campo para soportar las circunscripciones propuestas aquí.

Keywords

Colombia, Ecuador, Gesneriaceae, Kohleria, taxonomy

Introduction

The flowering plant family Gesneriaceae, with over 3400 species and 150+ genera (Weber 2004; Weber et al. 2013) is in the order Lamiales. The family is divided into three subfamilies and seven tribes (Weber et al. 2013, 2020). The majority of New World members are in the subfamily Gesnerioideae and are represented by 1200+ species and 77 genera (Clark et al. 2020). The New World subfamily Sanangoideae is limited to one genus and one species (Weber et al. 2013, 2020). Kohleria Regel is classified in the tribe Gesnerieae Dumort. and subtribe Gloxiniinae G. Don (Weber et al. 2013, 2020).

Kohleria was monographed by Kvist and Skog (1992), who recognized 17 species. An additional two species were transferred to Kohleria from Capanea Decaisne ex Planchon (Roalson et al. 2005a) based on molecular phylogenetic analyses of the tribe Gloxinieae (Roalson et al. 2005b). Clark and Skog (2008) described Kohleria hypertrichosa J.L. Clark & Skog from the western Andes of northern Ecuador. The recognition of two more Kohleria species here brings the total number in the genus to 22 species.

Kvist and Skog (1992) broadly defined many species in their monographic revision of Kohleria. For example, Kohleria hirsuta (Kunth) Regel var. hirsuta (sensu Kvist and Skog 1992) includes more than 40 names representing 15 heterotypic synonyms. Kvist and Skog (1992) noted a wide range of morphological variation when circumscribing taxa, and that variation was attributed to hybridization. Molecular tools, fieldwork, and ready access to digital images are necessary for evaluating many of these broadly circumscribed species. A current doctoral dissertation project by Kimberly Hansen from Washington State University (USA) and an undergraduate thesis by Katherin Arango-Gómez from the Universidad del Valle (Colombia) are evaluating the phylogeny and taxonomy of Kohleria based on the use of molecular tools, herbarium specimens, and extensive field work. The updated circumscriptions provided here will hopefully play a role in facilitating these active projects.

Results

New generic placement requires new combination and lectotypification for Kohleria andina

Kohleria andina (Fritsch) J.L. Clark & Jost, comb. nov.

Capanea andina Fritsch, Bot. Jahrb. Syst. 50: 431–432. 1913 (“1914”). Type: Ecuador. Andes Quitenses, Tunguragua, 1857, R. Spruce 5178 (lectotype K000395097, designated here; isolectotypes: BM000953512, E00062367, G00370826, G00370838, K000395097).

Remarks

One of the key characters discussed by Kvist and Skog (1992) as the basis for the generic circumscription of Kohleria was a terrestrial (i.e., non-epiphytic) habit. In the generic delimitation of Kohleria (Kvist and Skog 1992), the habit is described as herbs, subshrubs, shrubs, or rarely scandent shrubs. The terrestrial habit was considered a character by Kvist and Skog (1992) to differentiate Kohleria from closely related genera that are epiphytes or lianas. Phylogenetic studies by Roalson et al. (2005b) showed that Kohleria was paraphyletic with the exclusion of “Capanea”, a group of epiphytic subshrubs from the Andes. Thus, many of the features that differentiated “Capanea” from Kohleria, such as an epiphytic habit and four-valved capsules, are autapomorphic. The transfer of two species from “Capanea” to Kohleria is well-supported, and combinations were made by Roalson et al. (2005b). Roalson et al. (2005b) did not make a combination for Kohleria andina because it was considered a heterotypic synonym of Kohleria affinis. Examination of material in the field and in herbaria allowed us to recognize K. affinis and K. andina as different species. Outlined here are characters to differentiate K. andina from K. affinis (see Table 1 for a summary of the characters that are discussed below).

Table 1.

Morphological differences and general distribution of Kohleria affinis and K. andina.

Kohleria affinis (Fritsch) Roalson & Boggan Kohleria andina (Fritsch) J.L. Clark & Jost
Corolla tube shape usually narrow, rarely broad (Colombia) broad
Corolla tube color dark red to bright purple white
Corolla tube trichome color transparent yellow
Corolla tube length 3–6 cm < 3.5 cm
Peduncle and pedicel trichome color transparent purple
Distribution widespread in Colombia, Ecuador, and northern Peru endemic to the Ecuadorian province of Tungurahua)

Another feature that defines the clade previously recognized as “Capanea” is the presence of resupinate flowers via a twisted pedicel. The androecium and gynoecium are located in the lower region of the corolla tube (Fig. 1B, C and Fig. 2B, C). In contrast, all other Kohleria and closely related genera have the androecium and gynoecium in the upper region of the corolla tube.

Figure 1. 

Kohleria affinis (Fritsch) Roalson & Boggan A lateral view of flower B female phase of mature flower C male phase of mature flower D habit (A Clark et al. 7698 B Clark s.n. C Clark et al. 12979 D Clark et al. 15845). Photos by J.L. Clark.

The flowers of Kohleria affinis are often photographed because of their conspicuous clusters of brightly colored purple-red corolla tubes with contrasting green lobes (Fig. 1). It is common to see individuals with 50+ pendent flowers, especially in abandoned cow pastures or recently cleared forests. Herbarium specimens do not preserve floral colors and most corollas dry uniformly black. Thus, corolla colors are challenging to determine on dried herbarium specimens unless noted by collectors in the descriptions. Use of field-based images, review of taxonomic literature, and examination of type specimens provided information for re-assessing the circumscription of Kohleria affinis and K. andina.

The corolla tube of Kohleria andina is white, but appears bright yellow from dense tomentose yellow trichomes (Fig. 2). In contrast, the corolla tube of Kohleria affinis is dark red to bright purple (Fig. 1). The corolla tube in most Kohleria affinis is narrow, but some populations from Colombia are broad. The corolla tube of Kohleria andina is consistently broad. Corolla length in Kohleria affinis is highly variable and ranges from 3 to 6 cm. In contrast, the corolla tubes of Kohleria andina are usually less than 3.5 cm long. Both species have bright green corolla lobes that contrast with dark purple spots on the inner surface (Figs 1, 2).

Figure 2. 

Kohleria andina (Fritsch) J.L. Clark & Jost A lateral view of flower B female phase of mature flower C male phase of mature flower D habit (A–D Clark et al. 7750). Photos by J.L. Clark.

An additional character useful for differentiating Kohleria andina from K. affinis is the presence of dark red-purple trichomes on the peduncles and pedicels (Fig. 2A, D). The red-purple trichomes on the peduncles were noted by Fritsch (1913: page 432) in the protologue, “Pedunculi axillares elongati purpureo-villosi.” In contrast, the peduncles in Kohleria affinis are sparsely pilose and appear green due to transparent trichomes.

Kohleria andina and K. affinis are geographically separated by elevation. K. andina is endemic to elevations above 2500 meters on the western Andean slopes (Cordillera Oriental) in the Tungurahua province of Ecuador. In contrast, Kohleria affinis is widespread in the northern Andes of Colombia (Antioquia, Boyacá, Caldas, Caquetá, Cauca, Chocó, Cundimarca, Huila, Nariño, Putumayo, Quindío, Risaralda, and Valle del Cauca), Ecuador (Azuay, Bolívar, Carchi, Chimborazo, Cotopaxi, Esmeraldas, Imbabura, Loja, Napo, Pichincha, Santo Doingo, Tungurahua, and Zamora-Chinchipe), and northern Peru (Amazonas and Cajamarca). The authors’ field work from the upper slopes of Tungurahua, an active volcano in the western Andean slopes of the Cordillera Oriental, revealed little overlap. Kohleria andina is locally endemic to elevations above 2500 meters and K. affinis is widespread and located in forests below 2500 meters. Intermediate forms were not found here, indicating that these two forms are geographically separated by elevation and supported as different biological species.

Lectotypification

Syntypes are from two distinct localities: F.C. Lehmann 4869 (F0060498) from Colombia and R. Spruce 5178 from K (K000395097) from Tungurahua, Ecuador. The specimen of F.C. Lehmann 4869 (F) is more similar to the widespread Kohleria affinis. The specimen of R. Spruce 5178 from (K) is similar to the locally endemic Kohleria andina, and is designated as the lectotype to stabilize this species concept. According to Fritsch (1913), Richard Spruce cites Tunguarahua as a locality and the specimens have characters that are congruent with the Tungurahua populations featured in the images here (Fig. 2). The lectotype has a corolla that is wide and more ampliate (Fig. 2) relative to the narrower corolla tube of K. affinis (Fig. 1). An additional character that is congruent with material from the type locality and the lectotype (R. Spruce 5178) is the presence of dark red trichomes on the peduncles and pedicels. In contrast, the peduncle and pedicel trichomes on F.C. Lehmann 4869 are transparent and more similar to K. affinis.

Revised species circumscription for Kohleria anisophylla

Kohleria anisophylla (Fritsch) Wiehler

Kohleria anisophylla (Fritsch) Wiehler.

Kohleria anisophylla (Fritsch) Wiehler, Selbyana 5: 62. 1978. Type: Based on Diastema anisophyllum Fritsch.

Kohleria villosa var. anisophylla (Fritsch) Kvist & Skog, Smithsonian Contr. Bot. 79: 70. 1992. Type: Based on Diastema anisophyllum Fritsch. Basionym.

Diastema anisophyllum Fritsch, Bot. Jahrb. Syst. 50: 408. 1913 (“1914”). Type: Colombia. [Nariño] Piedra Ancha, West of Andes of Tuquerres, F.C. Lehmann 5843 (B, holotype not extant, lectotype K000509983, designated by Wiehler (1978: 62), isolectotype K000509984).

Nematanthus erianthus Bentham, Pl. Hartw: 231. 1846. Type: Ecuador. Pichincha: Quito towards Nanegal, Hartweg s.n. (holotype K000509985).

Columnea eriantha (Bentham) Hanstein, Linnaea 34: 391. 1865. Type: Based on Nematanthus erianthus Fritsch.

Diastema anisophyllum Fritsch var. quitense Fritsch. Bot. Jahrb. Syst. 50(4): 408. 1913 (“1914”). Type: Ecuador. [Pichincha] Quito, W. Jameson s.n. (holotype W).

Remarks

Kohleria anisophylla (Fig. 3) was previously recognized by Kvist and Skog (1992) as a variety of Kohleria villosa (Fig. 4). The strongly anisophyllous leaves and dorsiventral shoots (Fig. 3D) are more similar to Kohleria hypertrichosa (Fig. 5D) than K. villosa (Fig. 4D). All three species are found on the northwestern Andean slopes of Ecuador. Only Kohleria anisophylla is documented from Colombia (Nariño department). Wiehler (1978) made the combination Kohleria anisophylla and recognized it at the rank of species. Kvist and Skog (1992) recognized this taxon as Kohleria villosa var. anisophylla. Based on limited material, Wiehler (1978) cited the type (F.C. Lehmann 5843) and a recently collected specimen from Ecuador (C. Luer & A. Hirtz 2672). Kvist and Skog (1992) cited the same Ecuadorian collection and mentioned the study of eleven additional specimens. This species is common along the northwestern slopes of the Ecuadorian Andes, especially along the old road between Quito and Santo Domingo where many of the images were taken for Figure 3. Outlined here are characters to differentiate K. anisophylla, K. villosa, and K. hypertrichosa (see Table 2 for a comparison of characters that are discussed below).

Table 2.

Morphological differences and general distribution of Kohleria anisophylla, K. villosa, and K. hypertrichosa.

Kohleria anisophylla (Fritsch) Wiehler Kohleria villosa (Fritsch) Wiehler Kohleria hypertrichosa J.L. Clark & L.E. Skog
Habit facultative epiphyte terrestrial facultative epiphyte
Shoots dorsiventral erect dorsiventral
Relative leaf size anisophyllous isophyllous anisophyllous
Corolla vestiture villous villous tomentose
Distribution Ecuador (Bolívar, Carchi, Pichincha) and Colombia (Nariño) Ecuador (Bolívar, Carchi, Cotopaxi, Esmeraldas, Imbabura, Pichincha) northern Ecuador (Carchi and Esmeraldas)
Figure 3. 

Kohleria anisophylla (Fritsch) Wiehler A lateral view of flower B front view of corolla C mature fruit D dorsiventral habit with anisophyllous leaves (A, B Clark et al. 10981 C Clark 10948 D Clark et al. 14295). Photos by J.L. Clark.

The recent transfer (Roalson et al. 2005b) of Kohleria affinis and K. tigridia (Ohlend.) Roalson and Boggan represented an autapomorphic synapomorphy of epiphytism in traditionally recognized Kohleria. What is noteworthy about Kohleria anisophylla and K. hypertrichosa is their previously unreported epiphytic habits. Thus, the presence of an epiphytic habit in K. anisophylla and K. hypertrichosa could represent an additional independent origin of epiphytism in Kohleria. Several populations of Kohleria anisophylla were observed and documented with dorsiventral shoots, a feature that is common in facultative epiphytes in other Gesneriaceae genera. Many members of Columnea have strongly anisophyllous leaves – especially species that are facultative epiphytes with dorsiventral shoots. Other species of Gesneriaceae that are facultative epiphytes with dorsiventral shoots include Cremosperma anisophylla J.L. Clark & L.E. Skog, Drymonia anisophylla L.E. Skog & L.P. Kvist, and the majority of species in Monopyle Moritz ex Benth. and Trichodrymonia Oerst. Likewise, Kohleria anisophylla and K. hypertrichosa are facultative epiphytes with dorsiventral shoots and anisophyllous leaves. In contrast, Kohleria villosa is a terrestrial herb with isophyllous leaves (Fig. 4D).

Figure 4. 

Kohleria villosa (Fritsch) Wiehler A lateral view of flower B front view of corolla C mature fruit D erect herbaceous habit with isophyllous leaves (A Clark et al. 14295 B Clark 7331 C Clark et al. 7400 D Clark et al. 14295). Photos by J.L. Clark.

The corollas of Kohleria villosa and K. anisophylla are villous (Figs 3, 4). The corollas of Kohleria hypertrichosa are densely tomentose (Fig. 5). The specific epiphyte, “hypertrichosa” refers to the abundance of trichomes, which is why it is commonly known in the horticultural community as “Chewbacca,” a reference to the Wookie (fictional character) in the movie Star Wars.

Figure 5. 

Kohleria hypertrichosa J.L. Clark & L.E. Skog A lateral view of flower B front view of corolla C mature fruit D dorsiventral habit with anisophyllous leaves (A Clark et al. 15900 B Clark 6539 C Clark et al. 10310 D Clark et al. 14942). Photos by J.L. Clark.

Kohleria villosa and K. anisophylla are easily recognized when sterile. The opposite leaves of Kohleria anisophylla are consistently unequal in size or anisophyllous (Fig. 3D). In contrast, the opposite leaves of Kohleria villosa are consistently equal in size or isophyllous (Fig. 4D). In addition, the dorsiventral shoots distinguishes K. anisophylla from the erect shoots of K. villosus.

Acknowledgements

We thank Don Hector Yela for facilitating fieldwork in the Reserva Dracula where populations of Kohleria hypertrichosa are currently preserved. We thank Laura Clavijo from the Instituto de Ciencias Naturales – Universidad Nacional de Colombia for the Spanish translation of the Abstract and for providing helpful comments on the manuscript. Finally, we are grateful to Christian Feuillet and an anonymous reviewer for providing valuable feedback on an earlier version of the manuscript.

References

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