[Botany • 2025] Diastema calcicola (Gesneriaceae) • A New lithophytic Herb from southern Ecuador and northern Peru

 

 Diastema calcicola J. L. Clark and Moonlight,

in Clark et Moonlight, 2025. 

DOI: doi.org/10.1111/njb.04701 

  Researchgate.net/publication/390205962

 facebook.com/NordicJBotany

Abstract

Recent field expeditions in southern Ecuador and herbarium research resulted in the discovery of a new species of Diastema (Gesneriaceae). Diastema calcicola J. L. Clark and Moonlight, is described from limestone outcrops in northern Peru and the Cordillera del Cóndor in southern Ecuador. The new species is a lithophytic herb with unbranched shoots and an erect racemose inflorescence. Based on IUCN guidelines, a preliminary conservation assessment as ‘Vulnerable' (VU) is provided for D. calcicola.

Keywords: Cordillera del Cóndor, Diastema, Ecuador, Gesneriaceae, Peru, taxonomy

Field images of Diastema calcicola sp. nov. (Gesneriaceae).
(A) Front view of mature fruit, (B) dorsolateral view of mature fruit, (C) racemose inflorescence, (D) lateral view of mature flower, (E) front view of corolla, (F) habit.

(A) from J. L. Clark 10810; (B) from J. L. Clark 15080; (C)-(F) from J. L. Clark 16242. Photos by J. L. Clark.

 Diastema calcicola J. L. Clark and Moonlight, 

John L. Clark and Peter W. Moonlight. 2025. Diastema calcicola (Gesneriaceae), A New lithophytic Herb from southern Ecuador and northern Peru. Nordic Journal of Botany. DOI: doi.org/10.1111/njb.04701 [26 March 2025]

 facebook.com/NordicJBotany/posts/1249801750482385

  Researchgate.net/publication/390205962_Diastema_calcicola_a_new_lithophytic_herb_from_Ecuador_and_Peru

[Botany • 2025] Begonia chucantiensis (Begoniaceae, sect. Lepsia) • A New Species from the eastern mountains of Panama

 

Begonia chucantiensis Guillén, Moonlight & Jara, 

in Guillén, Moonlight, Jara-Muñoz, Stapf et Carrión, 2025. 

DOI: doi.org/10.3897/phytokeys.256.145404 

 

Abstract

Begonia chucantiensis sp. nov. is described as a new species of Begonia section Lepsia from Cerro Chucantí, Darién Province, in eastern Panama. A study of the literature and herbarium specimens, as well as fieldwork, suggests that the new taxon is distinguished from other species in the section by the combination of the following characters: uniform nodes, stipules persistent, 3.3–6 × 0.8–1.7 cm leaf blades, only two flowers per inflorescence, 12–14 stamens, and fruits with wings of similar shape and size. Images, information on geographic distribution, habitat, and a preliminary assessment of the conservation status of the new species are also provided.

Key words: Biogeographic isolation, Cerro Chucantí, Darién, Lepsia, Serranía de Majé

Holotype of Begonia chucantiensis sp. nov. (PMA132927).

Morphological aspects of Begonia chucantiensis sp. nov.
 A plant habit B fertile branches C detail of fertile branch D leaves viewed from the adaxial side and staminate flower E leaves viewed from the abaxial side, staminate flower and fruit F stipules G front view of staminate flower H pistillate flower I lateral view of the fruit.

 Images A, B, D, E C. Mitre-Ramos. C, F, I L. Guillén. G, H J.L. Guerra.

 Begonia chucantiensis Guillén, Moonlight & Jara, sp. nov.

 

Diagnosis. Within Begonia section Lepsia, B. chucantiensis resembles B. confinis in having persistent stipules and two flowers per inflorescence; however, it differs by having glabrous young branches and uniform nodes (vs. ferruginous indumentum and swollen nodes), stipules 8.5–10.5 × 3.5–4.5 mm (vs. 0.8–1.3 × 0.3–0.4 mm), elliptic to lanceolate leaf blades (vs. rhomboid subtrilobed), 3.3–6 × 0.8–1.7 cm leaf blades (vs. 0.6–1.3 × 0.3–0.6 cm), peduncles up to 1.3 cm (vs. 2.8 cm), 12–14 stamens (vs. 8–10), and fruits with similar wing shape and size (vs. one wing conspicuously unequal).

Lucila Guillén, Peter W. Moonlight, Orlando A. Jara-Muñoz, María Sánchez de Stapf and Juan F. Carrión. 2025. A New Species of Begonia (Begoniaceae) from the eastern mountains of Panama. PhytoKeys. 256: 61-71. DOI: doi.org/10.3897/phytokeys.256.145404 

Resumen: Se describe a Begonia chucantiensis sp. nov. como una nueva especie de Begonia sección Lepsia del Cerro Chucantí, provincia de Darién, en el este de Panamá. Un estudio de la literatura y especímenes de herbario, así como trabajo de campo, sugiere que el nuevo taxón se distingue de las otras especies de la sección por la combinación de los siguientes caracteres: nudos uniformes, estípulas persistentes, láminas foliares de 3.3–6 × 0.8–1.7 cm, solo dos flores por inflorescencia,12–14 estambres y frutos con alas similares en forma y tamaño. También, se proporcionan imágenes, información sobre la distribución geográfica, el hábitat y una evaluación preliminar del estado de conservación de la nueva especie.

[Botany • 2024] Begonia tamoiana (Begoniaceae) • A New Species from Atlantic Forest of Rio de Janeiro State, Brazil

  

Begonia tamoiana  

in Jacques, Moonlight et José dos Santos, 2024.

DOI: 10.11646/phytotaxa.669.2.8

 x.com/PeterMoonlight

 

Abstract

Begonia tamoiana is a new species endemic to Brazilian Atlantic Rainforest, a biome rich in endemism and species diversity, and it is described and illustrated herein. Begonia tamoiana is morphologically similar to B. magdalenensis but differs in having abaxial leaf blades with simple trichomes throughout (vs. 2-branched trichomes throughout) and ovate wings capsule (vs. triangular). A description, ecological comments, illustrations, color photographs, and a provisional IUCN conservation assessment of this species are provided. Begonia tamoiana is preliminarily classified as Vulnerable (VU) due to its very small populations and restricted distribution.

Atlantic Coastal Forest, conservation, endemism, taxonomy, Eudicots

Begonia tamoiana 

Eliane de Lima Jacques, Peter W. Moonlight and Alfredo José dos Santos Jr. 2024. Begonia tamoiana (Begoniaceae), A New Species from Atlantic Forest of Rio de Janeiro State, Brazil.  Phytotaxa. 669(2); 159-164. DOI: doi.org/10.11646/phytotaxa.669.2.8

 x.com/PeterMoonlight/status/1848753386612523188

[Botany • 2023] Pachycaulos huancabambae (Gesneriaceae) • Another Recently Recognized Monotypic Genus Is No Longer Monotypic: A Second Species of Pachycaulos from the Huancabamba Depression in Northern Peru

Pachycaulos huancabambae J.L.Clark & Moonlight,  

in Clark, Smith et Moonlight, 2023.

DOI: 10.1600/036364423X16936046516354

 twitter.com/PeterMoonlight

 

Abstract 

A new species is described from the Huancabamba Pass, a relict montane forest in northwest Peru, near the southwestern border of Ecuador. Pachycaulos huancabambae J.L.Clark & Moonlight is a terrestrial or lithophytic herb with scandent stems that grows in dense mats of bryophytes. This is the second species of Pachycaulos and renders that taxon as non-monotypic. We discuss several other genera of Gesneriaceae that are also no longer monotypic because of recent exploratory research in tropical forests and increased taxon sampling from ongoing phylogenetic studies. A molecular phylogenetic analysis based on nrDNA ITS is presented that strongly supports the monophyly and sister-group relationship of P. huancabambae and P. nummularia. Based on IUCN guidelines, a preliminary conservation status is assigned as Critically Endangered (CR).

Keywords: Andes; Columneinae; Gesnerieae; biodiversity; taxonomy

 Pachycaulos huancabambae J.L.Clark & Moonlight 

P. nummularifolia

 John L. Clark, James F. Smith and Peter W. Moonlight. 2023. Another Recently Recognized Monotypic Genus Is No Longer Monotypic: A Second Species of Pachycaulos (Gesneriaceae) from the Huancabamba Depression in Northern Peru.  Systematic Botany. 48(3); 410-418. DOI: 10.1600/036364423X16936046516354

 twitter.com/PeterMoonlight/status/1716863706624135424

artwork by Claire Banks 

[Botany • 2023] Begonia betancurii (Begoniaceae, sect. Ruizopavonia) • A New Species from the Eastern Cordillera of Colombia

Begonia betancurii 

in Jara-Muñoz, Moonlight et Zabala-Rivera, 2023.

DOI: 10.11646/phytotaxa.616.2.6 

twitter.com/PeterMoonlight

 

Abstract

A new species of Begonia section Ruizopavonia is here described and illustrated, and a key for the Colombian species of the section is also provided. The new species grows on the eastern side of the eastern Colombian Cordillera and can be recognized among species in the same section bearing staminate flowers with 4 tepals and pistillate flowers with 3 tepals by the larger outer tepals on both the staminate and pistillate flowers (>9.5 mm long). We assess the new species as Endangered (EN) under IUCN criteria; its protection is therefore recommended.

Keywords: Eudicots, Begoniaceae, Ruizopavonia, Colombia

O.A. Jara-Muñoz, P.W. Moonlight, J.C. Zabala-Rivera. 2023. ‏A New Species of Begonia (Begoniaceae) from the Eastern Cordillera of Colombia. Phytotaxa. 616(2); 169-175. DOI: 10.11646/phytotaxa.616.2.6

  twitter.com/PeterMoonlight/status/1706564058319610344

[Botany • 2016] Begonia speculum & B. erythrothrix (Begoniaceae, sect. Ignota) • Two New Peruvian Species of Begonia (Begoniaceae) and an Amended Description of Begonia thyrsoidea

Begonia speculum Moonlight & Tebbitt

in Moonlight & Tebbitt, 2016. 

DOI: 10.1017/S0960428616000299 

 twitter.com/PeterMoonlight 

 

Abstract

Begonia speculum is described and illustrated as a new species endemic to the San Martín Region of Peru, and compared with Begonia cremnophila Tebbitt and Begonia lutea L.B.Sm. & B.G.Schub. Begonia erythrothrix is described and illustrated as a new species endemic to the Cuzco Region of Peru, and compared with an updated description of Begonia thyrsoidea Irmsch., which is lectotypified. Using International Union for Conservation of Nature criteria, Begonia speculum is considered Vulnerable; B. erythrothrix and B. thyrsoidea are assessed as Data Deficient.

Keywords: Begonia cremnophila, Begonia sect. Eupetalum, Begonia sect. Quadriperigonia, Begonia thrysoidea, Peru

Begonia speculum Moonlight & Tebbitt. 
A and B, habitat (scale bar, 20 cm); C, habit (scale bar, 5 cm); D, leaf, abaxial surface (scale bar, 2.5 cm); E, tuber (scale bar, 2 cm); F, ovary, cross-section (scale bar, 3 mm); G, male flowers, front view (scale bar, 5 mm); H, female flowers, front view (scale bar, 10 mm); I, immature female flower, side view (scale bar, 5 mm).

Photographs from type collection P.W. Moonlight & A. Daza 158.

 twitter.com/PeterMoonlight 

 

Begonia speculum Moonlight & Tebbitt, sp. nov. § Ignota.

Etymology. The epithet ‘speculum’ is derived from the Latin word for ‘mirror’ and emphasises the symmetry of the leaves and male flowers, and the occasional two locular ovary and two styles of the female flowers of this species.

Begonia erythrothrix Tebbitt & Moonlight, sp. nov. § Ignota.

Etymology. The name ‘erythrothrix’ refers to the dense indumentum of red hispid hairs that covers the petioles and peduncles of this species.

 

P. W. Moonlight and M. C. Tebbitt. 2016. Two New Peruvian Species of Begonia (Begoniaceae) and an Amended Description of Begonia thyrsoidea. Edinburgh Journal of Botany. 74(2); 111 - 122. DOI: 10.1017/S0960428616000299

  twitter.com/PeterMoonlight/status/811186701024555010

Researchgate.net/publication/311731411_Two_New_Peruvian_Species_of_Begonia

[Botany • 2019] Begonia joshii (Begoniaceae, sect. Eupetalum) • A New Species of Tuberous Begonia from Andean Peru

Begonia joshii 

in Moonlight, Hollands, Cano & Purvis, 2019. 

 DOI: 10.1017/S0960428619000301 

  twitter.com/PeterMoonlight

Abstract

A striking new species of Begonia, B. joshii, is described from Amazonas Region, Peru. The new species is unusual among the South American members of the genus both in its combination of tuberous habit with peltate leaves and in living in a seasonally dry tropical forest environment. A phylogeny of this and closely related species is presented, and its sectional affiliation and IUCN conservation status are discussed. A key to the peltate Peruvian species of Begonia is provided.

Keywords: Begonia sect. Eupetalum, large genera, new species, Peru

P. W. Moonlight, R. Hollands, A. Cano and D. A. Purvis. 2019. A New Species of Tuberous Begonia (Begoniaceae) from Andean Peru. Edinburgh Journal of Botany. First View. DOI: 10.1017/S0960428619000301  

 twitter.com/PeterMoonlight/status/1177228879938932741

[Botany • 2019] Diastema fimbratiloba (Gesneriaceae) • A New Species of Diastema from the eastern Andean Slopes of Peru

Diastema fimbratiloba Moonlight & J.L.Clark

in Clark & Moonlight, 2019. 

 DOI:  10.1017/S0960428619000192 

  twitter.com/PeterMoonlight 

Abstract

A striking new species of Diastema, D. fimbratiloba, is described from Ucayali Region, along the eastern Andean slopes in central Peru. The new species has a fimbriate lower corolla lobe, a feature not previously documented in the genus. We also provide a general comparison of the newly described species and morphologically related species in the context of the taxonomy and phylogeny of the poorly known genus Diastema.

Keywords: Diastema, Gesneriaceae, Peru.

Diastema fimbratiloba Moonlight & J.L.Clark, sp. nov.

Photograph taken by P. W. Moonlight 

of the type collection in the field.

Diastema fimbratiloba Moonlight & J.L. Clark, sp. nov.
 A, Habit; B, dissected corolla tube, showing the androecium; C, abaxial view of the calyx lobes; D, gynoecium, side view; E, nectary and base of the gynoecium, side view; F, stigma, side view; G, anthers, bottom view. Scale bars: A, 3 cm; B–D, 6 mm; E–G, 3 mm. Illustration by C. Banks from the type collection.

Diastema fimbratiloba Moonlight & J.L.Clark, sp. nov. 

Etymology. The species is named for the distinctive fimbriations on the lower corolla lobe. Fimbriations are common in several genera of New World Gesneriaceae (especially Drymonia Mart.), but no currently known described species in Diastema is known for this feature. It is possible that other species of Diastema have fimbriate corolla margins (cf. note above regarding the population without collection from Atalaya, Peru), but this is a difficult character to evaluate from collections, because the flowers are delicate and ephemeral. As a result, corolla features in Diastema are not readily available on most herbarium specimens.

J. L. Clark and P. W. Moonlight. 2019. A New Species of Diastema (Gesneriaceae) from the eastern Andean Slopes of Peru. Edinburgh Journal of Botany: An International Journal of Plant Systematics and Biodiversity. DOI:  10.1017/S0960428619000192  

 twitter.com/PeterMoonlight/status/1165935447241043968

[Botany • 2018] Dividing and Conquering the Fastest-growing Genus: Towards A Natural Sectional Classification of the Mega-diverse Genus Begonia (Begoniaceae)

Begonia spp.

in Moonlight, Ardi, Arroyo Padilla, Chung, Fuller, et al., 2018.

DOI:  10.12705/672.3 

twitter.com/PeterMoonlight 

 facebook.com: Mark Hughes

Abstract

The pantropical genus Begonia is the sixth-largest genus of flowering plants, including 1870 species. The sections of Begonia are used frequently as analogues to genera in other families but, despite their taxonomic utility, few of the current sections have been examined in the light of molecular phylogenetic analyses. We present herein the largest, most representative phylogeny of Begonia published to date and a subsequent provisional sectional classification of the genus. We utilised three plastid markers for 574 species and 809 accessions of Begonia and used Hillebrandia as an outgroup to produce a dated phylogeny. The relationships between some species and sections are poorly resolved, but many sections and deeper nodes receive strong support. We recognise 70 sections of Begonia including 5 new sections: Astrothrix, Ephemera, Jackia, Kollmannia, and Stellandrae; 4 sections are reinstated from synonymy: Australes, Exalabegonia, Latistigma and Pereira; and 5 sections are newly synonymised. The new sectional classification is discussed with reference to identifying characters and previous classifications.

Keywords: Begonia; dating; phylogenetics; sectional classification

          

Begonia (sect. Jackia) sublobata Jack, on Pulau Pasumpahan, Sumatra

 twitter.com/markhughesis

 Peter W. Moonlight, Wisnu H. Ardi, Luzmila Arroyo Padilla, Kuo-Fang Chung, Daniel Fuller, Deden Girmansyah, Ruth Hollands, Adolfo Jara-Muñoz, Ruth Kiew, Wai-Chao Leong, Yan Liu, Adi Mahardika, Lakmini D.K. Marasinghe, Meriel O'Connor, Ching-I Peng, Álvaro J. Pérez, Thamarat Phutthai, Martin Pullan, Sangeeta Rajbhandary, Carlos Reynel, Rosario R. Rubite, Julia Sang, David Scherberich, Yu-Min Shui, Mark C. Tebbitt, Daniel C. Thomas, Hannah P. Wilson, Nura H. Zaini and Mark Hughes. 2018.  Dividing and Conquering the Fastest-growing Genus: Towards A Natural Sectional Classification of the Mega-diverse Genus Begonia (Begoniaceae). Taxon. 67(2); 267-323. DOI:  10.12705/672.3

Begonia sect. Jackia, named after the indefatigable Aberdonian botanist William Jack, is one of 5 new Begonia sections published today @TheBotanics. Pic is the type, B. sublobata Jack, on Pulau Pasumpahan, Sumatra. DOI:  10.12705/672.3  for IAPT members or PM me for the paper

 twitter.com/markhughesis/status/994208418469687296

twitter.com/PeterMoonlight/status/994196902584479744

 facebook.com/photo.php?fbid=10213926341885373

[Botany • 2017] A Revision and Recircumscription of Begonia Section Pilderia including One New Species, Begonia tepuiensis

Begonia tepuiensis Moonlight & Jara  

DOI: 10.11646/phytotaxa.307.1.1 

Abstract

Novel phylogenetic data is used to show that the poorly-known species Begonia glandulifera and Begonia mariannensis form a clade with Begonia buddleiifolia, the type species of Begonia section Pilderia. A unique combination of characters is identified in this group and used to re-circumscribe the section to include these species, and two morphologically similar species: Begonia jenmanii, and Begonia humilliana. A new species is described herein as Begonia tepuiensis sp. nov. from a single tepui in the Amazonas State of Venezuela. A full taxonomic revision and key to the species of Begonia section Pilderia is presented and we assign all species to IUCN Red List categories.

Keywords: Andes, Begonia section Pilderia, Neotropics, Phylogeny, Guyana Shield, Trinidad and Tobago, Eudicots

Begonia section Pilderia (Klotzsch) A.DC. 

 Distribution:— Colombia, Ecuador, Guyana, Perú, Trinidad and Tobago, Venezuela. 

1. Begonia buddleiifolia A.DC. (1859)

2. Begonia glandulifera Griseb. (1860) 

3. Begonia humillima L.B.Sm. & Wassh. (1973)  

4. Begonia jenmanii Tutin (1940) 

5. Begonia mariannensis Wassh. & T. McClellan (1995) 

6. Begonia tepuiensis Moonlight & Jara spec. nov.

Etymology:— The genus Begonia is relatively poorly known from the tepuis of northern Amazonia. We name this species B. tepuiensis as it is only the third Begonia species described exclusively from tepuis after B. steyermarkii L.B.Sm. & B.G.Schub and B. nubicola L.B.Sm. & B.G.Schub.

FIGURE 6. Begonia tepuiensis Moonlight & Jara. 
A. Habit, flowering top; B. Habit, shoot with rooting nodes; C. Female flower (side view); D. Stigma (front view); E. Stigma (back view); F. Bract; G. Detail of leaf hairs, upper lamina; H. Detail of leaf hairs, lower lamina. 

Drawn from type collection R.S. Cowen & J.J. Wurdack 31443 by Claire Banks. 

twitter.com/PeterMoonlight

P.W. Moonlight and A. Jara-Muñoz. 2017. A Revision and Recircumscription of Begonia Section Pilderia including One New Species. Phytotaxa. 307(1); 1-22.  DOI: 10.11646/phytotaxa.307.1.1.

twitter.com/PeterMoonlight/status/865465112059977728

Resumen: Se usaron nuevos datos filogenéticos para mostrar que las especies pobremente conocidas: Begonia glandulifera y Begonia mariannensis forman un clado con Begonia buddleiifolia, la especie tipo de Begonia sección Pilderia. Se identificaron una combinación única de caracteres en este grupo, que fueron usados para re-circunscribir la sección incluyendo estas especies, y dos especies morfológicamente similares: Begonia jenmanii y Begonia humilliana. Se describe una nueva especie, Begonia tepuiensis sp. nov. de un tepui en el estado Amazonas de Venezuela. Se presenta también una revisión taxonómica completa y una clave para las especies de Begonia sección Pilderia y asignamos todas las especies a categorías de la Lista Roja de la UICN.

[Botany • 2017] Begonia elachista Moonlight & Tebbitt sp. nov. • An Enigmatic New Species and A New Section of Begonia (Begoniaceae) from Peru

Begonia elachista 

Moonlight & Tebbitt

DOI: 10.5852/ejt.2017.281

Abstract

The world’s smallest Begonia, Begonia elachista Moonlight & Tebbitt sp. nov., is described and illustrated from a limestone outcrop in the Amazonian lowlands of Pasco Region, Peru. It is placed within the newly described, monotypic Begonia sect. Microtuberosa Moonlight & Tebbitt sect. nov. and the phylogenetic affinities of the section are examined. Begonia elachista sp. nov. is considered Critically Endangered under the International Union for the Conservation of Nature (IUCN) criteria.

Keywords: Begonia; sectional classification; limestone endemics; Peru; Amazonia

Fig 3. Begonia elachista Moonlight & Tebbitt sp. nov. 
[Begonia sect. Microtuberosa Moonlight & Tebbitt sect. nov.]A. Whole plant. B. Male and female flower, front view. C. Female flower, side view. D. Habit and associated vegetation. E–F. Habitat and wild population.

Scale bars: A = 1 cm; B = 5 mm; C = 2 mm; D = 2 cm; E–F = 10 cm.
Photographed by Peter Moonlight. All from P. Moonlight & A. Daza 318 (E). 

DOI: 10.5852/ejt.2017.281

Taxonomic Treatment

Class Equisetopsida C.Agardh (Agardh et al. 1825)

Subclass Magnoliidae Novák ex Takht. (Takhtajan 1967)

Superorder Rosanae Takht. (Takhtajan 1967)

Order Cucurbitales Juss. ex Bercht. & J.Presl (von Berchtold & Presl 1820)

Family Begoniaceae C.Agardh (Agardh 1824)

Genus Begonia L. (Linnaeus 1753)

Begonia sect. Microtuberosa Moonlight & Tebbitt sect. nov.

 Diagnosis: Begonia sect. Microtuberosa sect. nov. is most closely related to B. sect. Trachelocarpus and three species of B. sect. Gaerdtia. Both of these sections are endemic to eastern Brazil and differ markedly from sect. Microtuberosa sect. nov. in both their habit and floral characteristics (see Table 1). However, all three sections share their filaments fused at least at the base and B. sect. Microtuberosa sect. nov. further shares its androecium morphology with B. sect. Pereira and its lack of bracteoles with B. sect. Trachelocarpus. The majority of both floral and vegetative characters are, however, markedly different among the three sections.

Begonia sect. Microtuberosa sect. nov. is readily identified as the only Neotropical section of Begonia with male flowers with four or fewer stamens, and the combination of ovaries with two or three locules and entire placentas, and a tuberous habit.

Etymology: The name ‘Microtuberosa’ emphasises the diminutive and tuberous habit of the type species. 

Type species: Begonia elachista Moonlight & Tebbitt sp. nov. 

Distribution: On a limestone outcrop in lowland Amazonian Peru to the east of the Chemillén Cordillera at an altitude of 430 m.

Begonia elachista Moonlight & Tebbitt sp. nov. sect. Microtuberosa

Diagnosis: Begonia elachista sp. nov. is a highly distinct species with an unusual combination of features that is easily recognized as the only Peruvian species of Begonia that reaches maturity at fewer than 5 cm in height. It is also unique within Peru in having ovate leaves smaller than 3 × 3 cm and a combination of entire placentae and a tuberous habit.

Etymology: The epithet ‘elachista’ comes from the Greek for ‘least’ and emphasizes the diminutive size of this species, which is the smallest known species of Begonia.

Distribution and habitat: Begonia elachista sp. nov. is known only from the type locality in the Peruvian region of Pasco (Oxapampa Province) and has been collected on calcareous rocks by the entrance to a cave within primary lowland Amazonian forest, at an altitude of 430 m. It was observed growing on rocks free from other vascular plants in association with various bryophyte species in the almost continual shade of the surrounding forest.

.....

Peter Watson Moonlight, Carlos Reynel and Mark Tebbitt. 2017.  Begonia elachista Moonlight & Tebbitt sp. nov., An Enigmatic New Species and A New Section of Begonia (Begoniaceae) from Peru. European Journal of Taxonomy.  281: 1–13.  DOI: 10.5852/ejt.2017.281