Webbia. Journal of Plant Taxonomy and Geography 75(1): 123-132, 2020 Firenze University Press www.fupress.com/webbia W EB B IA Journal of Plant Taxonomy and Geography ISSN 0083-7792 (print) | ISSN 2169-4060 (online) | DOI: 10.36253/jopt-8091 Citation: Cedeño-Fonseca M. et al. (2020) Two new endemic species of Monstera (Araceae: Monsteroideae: Monstereae) from Golfito in south- ern Costa Rica. Webbia. Journal of Plant Taxonomy and Geography 75(1): 123-132. doi: 10.36253/jopt-8091 Received: February 14, 2020 Accepted: March 18, 2020 Published: June 30, 2020 Copyright: © 2020 Marco Cedeño- Fonseca, Alistair Hay, Michael H. Gray- um, Mario A. Blanco. This is an open access, peer-reviewed article published by Firenze University Press (http:// www.fupress.com/webbia) and distrib- uted under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, pro- vided the original author and source are credited. Data Availability Statement: All rel- evant data are within the paper and its Supporting Information files. Competing Interests: The Author(s) declare(s) no conflict of interest. Editor: Peter C. Boyce Two new endemic species of Monstera (Araceae: Monsteroideae: Monstereae) from Golfito in southern Costa Rica Marco Cedeño-Fonseca1,*, Alistair Hay2, Michael H. Grayum3, Mario A. Blanco1,4,5 1 Programa de Posgrado en Biología / Herbario Luis Fournier Origgi (USJ), Universidad de Costa Rica, San José, Costa Rica 2 Royal Botanic Gardens, Mrs Macquarie’s Road, Sydney 2000, Australia 3 Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, MO 63110, USA 4 Jardín Botánico Lankester, Universidad de Costa Rica, P. O. Box 302-7050 Cartago, Cos- ta Rica 5 Escuela de Biología and Centro de Investigación en Biodiversidad y Ecología Tropical, Universidad de Costa Rica, 11501–2060 San José, Costa Rica *Corresponding author. E-mail: marcovf.09@gmail.com Abstract. Monstera croatii M.Cedeño & A.Hay and M. gambensis M.Cedeño & M.A.Blanco (Araceae: Monsteroideae: Monstereae) are newly described and illustrated from cantón Golfito in the Pacific lowlands of southern Costa Rica. Notes are provided on how they can be differentiated from similar species. Monstera croatii is unique in the genus because it reaches its adult vegetative morphology while growing as a terres- trial plant on the forest floor, and climbs only to a very limited height before flowering. Monstera gambensis is one of the smallest species in the genus. Keywords: Aroids, Central America, Osa Peninsula. INTRODUCTION In Costa Rica there are some 24 genera and 256 species of Araceae (including subfamily Lemnoideae, commonly treated as a separate family), the most well-represented of the genera being Anthurium Schott, Philoden- dron Schott, and Monstera Adans. (Grayum 2003; Ortiz et al. 2018). These groups are abundant and diverse in very humid lowland forests and in cloud forests (Grayum 2003). Monstera is a genus that consists mostly of nomadic vines (sometimes referred to as hemi-epiphytes, but see Zotz 2013), and is best known for its often conspicuously perforated leaves (Grayum 2003; Cedeño- Fonseca et al. 2018; Hay 2019). Molecular-phylogenetic analyses of subfamily Monsteroideae agree in finding Monstera to be a monophyletic genus most closely allied to the tropical Asian genus Amydrium Schott and some (but not all) species of the likewise Asian Epipremnum Schott, and it is the only neotropical member of the pantropical tribe Monstereae or ‘Rhaphidophora 124 Marco Cedeño-Fonseca et al. clade’ (Tam et al. 2004; Zuluaga et al. 2019). It is consid- ered one of the taxonomically most poorly understood aroid groups in Mesoamerica (Madison 1977; Croat 1992; Jácome and Croat 2002; Grayum 2003). The most recent taxonomic revision (Madison 1977) recognized 22 species in the entire genus. However, the first author’s current research, revising Monstera for Central America, indi- cates that there are more than 40 species in this region alone (Cedeño-Fonseca 2019), with an as yet undeter- mined number of further species from Mexico, tropical South America, and the Caribbean. The genus is currently divided into four sections — Echinospadix Madison, Marcgraviopsis Madison, Tornelia (Gutiérrez ex Schott) Madison, and Monstera (Madison 1977; Mayo et al. 1997; Croat et al. 2010) — though it is doubtful whether this infrageneric classifi- cation will stand up to molecular analysis (e.g., Zuluaga et al. 2019). Section Monstera includes, among others, several small, mainly South American species — Mon- stera obliqua Miq. (Costa Rica to Ecuador, Perú, Vene- zuela, the Guianas and Brazil), M. xanthospatha Madi- son (western Colombia), and M. minima Madison (Pan- ama and Colombia) (Madison 1977; Jácome and Croat 2002) — and during recent fieldwork in the forests of La Gamba, Golfito, a new diminutive species was collect- ed, which is described and illustrated here. In addition, a species with terrestrial (or near terrestrial) habit was also collected in Golfito, which only ascends on the pho- rophyte to about 1.5 m above ground level. This species has also proven to be undescribed, and is named here. It too belongs to sect. Monstera sensu Madison (1977). Monstera croatii M.Cedeño & A.Hay, sp. nov. Type: Costa Rica, Puntarenas Province, Golfito Can- ton, Golfito, camino hacia las antenas, 8°38’55.1’’N, 83°9’30.8’’W, 389 m, 4 February 2019 (fr.), M. Cedeño & A. Hay 1624 (holotype: USJ [2 sheets]). (Figures 1, 2). Diagnosis Monstera croatii is recognized by its terrestrial or very low nomadic-vining habit, petioles glaucous at the base, with the sheath extending to about half the total length, the sheath margins involute, and the free portion terete, grey- ish-glaucous leaf blades, adult leaf blades deeply pinnati- fid, peduncles with a persistent mucronate cataphyll, and spadices with more or less spherical basal sterile flowers. Description Moderately robust terrestrial herb to appressed nomadic vine, flowering at ca. 0.5–1.5 m above ground level. Seed- lings not observed. Juvenile plants terrestrial; stem pale to dark green, smooth, terete, with internodes 1–2.4 cm long by 0.5–1 cm diam.; petioles visible (i.e., the blades not shingling), pale to dark green, smooth, 8–10 cm long, sheathed in the lower 3–6 cm, the wings persistent, above the sheath more or less terete to slightly chan- neled; leaf blades not appressed to the substrate, 10–20 × 4–10 cm, lanceolate, narrowed to the base, acuminate at the apex, thinly coriaceous, with or without fenestra- tions and if fenestrate then generally on only one side and breaking at the margin. Adult plants terrestrial and eventually becoming appressed-climbing before flow- ering; stem dark green to pale brown, terete, the inter- nodes 1–1.5 cm long, 1.5–2 cm diam., with pale brown- hairy support and feeder roots; petioles rather pale bluish green, glaucous/pruinose, smooth, 34–45 cm long, sheathed in the lower 20–28 cm, with the wings persistent and involute, the free portion terete, slightly canaliculate near the geniculum; geniculum more or less terete, very slightly canaliculate adaxially, 2–2.5 cm long; leaf blades 30–45 × 25–33 cm, oblong-ovate, rounded to asymmetric at the base, shortly acuminate at the apex, subcoriaceous, deeply pinnatifid but not fenestrate, not decurrent onto the geniculum, glaucous abaxially, the anterior costa canaliculate adaxially, con- vex abaxially, primary lateral veins 8–13 per side, adaxi- ally impressed, abaxially prominent; secondary and ter- tiary venation parallel; collective vein visible at the mar- gins of each lobe; lobes 6–12 per side, 0.5–2.5 cm wide, with 1 or 2 primary veins each, sometimes distally bifid. Inflorescences on ascending shoots, 1–2 per flowering episode, subtended by basally sheathing, greenish, dis- tally 3-keeled, apically mucronate, persistent cataphylls; peduncle smooth, 20–25 cm long; spathe acuminate, with two longitudinal keels, membranaceous, light green at pre-anthesis, white-yellowish externally and white inter- nally at anthesis, marcescent after the anthesis, 9–14 × 3–5 cm; spadix white in pre-anthesis and anthesis, 6–8 × 2.5–3 cm in early fruit, the basal zone of sterile flow- ers slender, very conspicuous; sterile flowers 3–5 mm long, round with a very prominent stigmatophore; fertile flowers 5–6 mm long; stamens with laminar filaments 2–5 mm long; anthers 1–2 mm de long; ovary square- prismatic, 1.5–3 × 1.5–2 mm; style squarish, rounded or hexagonal, 0.5–1 × 2–3 mm; stigma linear. Infructescence with the stylar caps green after anthesis; mature fruits not observed; seeds not observed. Etymology The new species is named for Dr. Thomas B. Croat (MO), the leading authority on neotropical Araceae. He also realized that some herbarium specimens of this spe- 125Two new endemic species of Monstera (Araceae: Monsteroideae: Monstereae) Figure 1. Monstera croatii. A. Developing inflorescence. B. Front and back views of open inflorescence. C. Fertile flower in lateral view (left) and in longitudinal section (right). D. Stylar plate, top view (left), and individual stamen (right). E. Sterile flower in lateral view (left) and in longitudinal section (right). F. Infructescence. G. Juvenile plant. H. Adult plant. 126 Marco Cedeño-Fonseca et al. Figure 2. Adult plant of Monstera croatii (see description for dimensions). A. Hemi-epiphytic habit, ascending to only 1.5 m above the ground, showing the glaucous leaf colour especially on the youngest leaves. B. Terrestrial habit, with the same morphology as that of reproductive individuals. C. Young infructescences with the green stylar layer, conspicuous basal sterile zone, and persistent subtending cataphylls. D. The base of the glaucous/pruinose petiole and persistent involute petiole sheath (arrow). E. Part of the petiole completely terete beyond the sheath. F. Leaf with two primary veins per lobe, sometimes bifid into lobules that divide up to 4 cm away from the costa (arrow). Photographs: M. Cedeño-Fonseca. 127Two new endemic species of Monstera (Araceae: Monsteroideae: Monstereae) cies, previously identified as M. pinnatipartita Schott, could represent a different, undescribed species. Distribution and habitat Monstera croatii is endemic to Costa Rica, where it is known only from the south on the Pacific side in the region of Golfito and the Parque Nacional Corcovado (both in the cantón of Golfito) at ca. 300–600 m, in pri- mary and secondary forest and in open areas (Figure 6). Phenology Immature infructescences recorded in February; flower- ing observed in October and November. Conservation status Monstera croatii is protected in the Refugio Nacional de Vida Silvestre Golfito and in the Parque Nacional Cor- covado. Notes Monstera croatii is differentiated from all other Costa Rican species of Monstera by having pruinose/glaucous stems and petioles, the petioles sheathing for about half their length, with the sheath wings involute and persis- tent and the free (distal) part terete or only weakly chan- neled. It is further differentiated by the deeply pinnatifid and bluish green leaf blades, sometimes with bifid lobes, and the pruinose peduncles with a persistent sheathing mucronate cataphyll. A unique characteristic of this species is its terrestrial habit, reaching the adult vegetative stage in this state and climbing only to very limited height before flower- ing. Fertile terrestrial individuals were not found, but one plant was observed fertile after climbing only 50 cm above ground level with the same stem and leaf mor- phology as terrestrial examples. Monstera croatii has sterile f lowers with the ovary spherical, as is also the case in M. glaucescens Croat & Grayum, which too has glaucous stems and briefly sheathed petioles, but that species (known only from the Caribbean side of Costa Rica) has the leaves pin- nately lobed (never deeply pinnatifid), the petiolar sheath persistent but not with involute margins, and the non-sheathing part of the petiole channeled (nev- er terete). Monstera croatii can also be confused with Monstera pinnatipartita, but that species has the peti- oles green or speckled (never glaucous), never develops to the adult vegetative form on the ground, is fertile only after significantly ascending its phorophyte, and has acuminate and marcescent (not mucronate and per- sistent) cataphylls. Additional specimens studied (Paratypes): COSTA RICA. Puntarenas, Golfito, Golfito, camino hacia las antenas, 8°38’55.1’’N, 83°9’30.8’’W, 389 m, 4 February 2019 (fr.), M. Cedeño & A. Hay 1625 (USJ [2 sheets]). Puntarenas, Golfito, Golfito, camino a las tor- res del I.C.E., aprox. 2 km antes de llegar, 8°39’25’’N, 83°9’25’’W, 389 m, 29 January 1992 (fr.), Á. Fernández 205 (CR, MO [3 sheets]). Puntarenas, Golfito, Parque Nacional Corcovado, Estación Agujas, Cerro Rincón, 8°31’34.467’’N, 83°28’3.9’’W, 600 m, 11 November 1999 (fl.), E. Mora 725 (CR [2 sheets]). Monstera gambensis M.Cedeño & M.A.Blanco, sp. nov. Type: Costa Rica, Puntarenas Province, Gol6to Canton, Gol6to, La Gamba, sendero sobre quebrada, 8°41’02’’ N, 83°12’15’’W, 94 m, 27 May 2016, M. Cedeño, A. P. Karre- mans & I. Chinchilla 890 (holotype: USJ) (Figures 3, 4, 5). Diagnosis Monstera gambensis is recognised by its small entire leaves with or without fenestrations, and its asperous petioles with involute sheath margins that appear whit- ish. Similar in size to Monstera obliqua, it differs from that species by having asperous (vs. smooth) petioles, with the sheath margins persistent (vs. completely decid- uous), and smaller leaf blades (12–24 × 5–10 cm, vs. ca. 35 × 14 cm). Description Nomadic vines, fertile at ca. 2 m above the ground. Seedlings unknown. Juvenile plants appressed-climbing; stem dark green, slightly rough, internodes 3–5 cm long, 4–10 mm diam.; petioles visible (i.e., the leaves not shin- gling), dark green or light, slightly rough, 3–5 cm long, sheathed to the base of the geniculum, the wings persis- tent; leaf blades more or less horizontal, not flattened to the substrate of the phorophyte, 4–7 × 3–4 cm, obovate or lanceolate, subcordate to truncate at the base, acumi- nate at the apex, thinly coriaceous, without fenestra- tions. Adult plants appressed-climbing; stem terete, dark green, rough, internodes 1–4 cm long, 5–10 mm diam.; supporting roots black and corky, 4–6 cm long, feeder roots black and semi-corky, both with black root hairs; leaves numerous, sub-erect; petioles light green or whit- ish, rough to the geniculum, 17–22 cm long, sheathed to 2–3 cm below the base of the geniculum with the wings involute and persistent, the free portion slightly grooved; geniculum elongated, 0.5–1 cm long; leaf blades 12–24 × 5–10 cm, lanceolate, attenuate and decurrent on the 128 Marco Cedeño-Fonseca et al. geniculum at the base (the decurrent part 0.5–1 mm wide), acuminate at the apex, without or (less common- ly) with fenestrations (when present, one to two perfora- tions close to each other on the same side of the blade near its middle part), often only one side fenestrated, with entire margins, subcoriaceous; anterior costa chan- Figure 3. Monstera gambensis. A. Adult plant showing leaves without perforations. B. Cross-section of petiole showing involute sheath wings. C. Juvenile plant. D. Petiole of adult plant with persistent sheath and involute sheath wings. E. Mature infructescence with persistent cataphylls at the base. Illustration by Sara Díaz Poltronieri. 129Two new endemic species of Monstera (Araceae: Monsteroideae: Monstereae) neled adaxially, convex to the middle of the blade abaxi- ally, slightly rough, with 5–13 primary lateral veins on each side, impressed or indistinct abaxially, prominent on the underside, collective vein not visible. Inflores- cences on ascending stems; peduncle rough throughout, 20–25 cm long; spathe unknown; spadix 7–10 × 1.3–1.6 cm, colour at and before anthesis unknown; sterile flow- ers 3–4 mm long; fertile flowers 4–5 mm long; stamens with laminar filaments 2–4 mm long; anther 1–2 mm long; ovary prismatic, longitudinally ribbed, 2–3 × 2–3 mm; stylar region hexagonal, 1–2 × 3–5 mm; stigma lin- ear. Infructescence yellow when ripe; fruits with white pulp; seeds black, 2–3 mm long. Etymology The epithet gambensis refers to the type locality. Distribution and habitat Monstera gambensis is endemic to Costa Rica, where it has been found growing low on the supporting trees (ca. 2 m above ground level), in rain forest at La Gamba Bio- logical Station, cantón Golfito, mostly at 50–100 m. (Fig- ure 6). Phenology Flowering has not been observed. An infructescence was recorded in May. Conservation status It is protected at the La Gamba Biological Station, the only known locality for this species. Notes Monstera obliqua, a species whose type is from Surinam and which in its current, broad conception extends into Amazonia, is known in Costa Rica only from the south- eastern corner of the country (Grayum 2003), while the Costa Rican endemic M. gambensis is known only by a single collection from La Gamba, Golfito. Monstera gambensis is one of the smallest species in the genus, Figure 4. Monstera gambensis. A. Adult plant with non-perforated leaves. B. Juvenile plant. C. Adult leaf with two perforations. Photo- graphs: M. Cedeño-Fonseca. 130 Marco Cedeño-Fonseca et al. together with M. obliqua and M. minima. The latter, with smaller petioles (2–6 cm), leaf blades (9–14 × 2–4 cm), and spadices (ca. 4.4 × 09–1 cm) even smaller than those of M. gambensis (Jácome & Croat 2002), is only known from the northern (Caribbean) coast of Panama and along the Pacific slope of northern Colombia, in the Figure 5. Monstera gambensis. A. Support roots (i) and a feeding root (ii) both corky and blackened. B. Petiole sheath margins persistent and involute in adult plants (arrow). C. Petioles with sheath margins persisting, whitish and asperous (arrow). D. Internodes of adult plant (arrow). E. The shallowly channeled distal portion of the petiole (arrow). F. Portions of either dead epidermis or epicuticular waxes that give a whitish appearance and an asperous texture to the surface of the petioles. Photographs: M. Cedeño-Fonseca. 131Two new endemic species of Monstera (Araceae: Monsteroideae: Monstereae) Chocó region (Jácome and Croat 2002). In Costa Rica, M. gambensis is found in lowland tropical wet forest at elevations of up to ca. 100 m. The individuals observed were climbing in the undisturbed forest on small trees no more than 2.5 m high, with abundant shade in the understorey. Most adult leaves of Monstera gambensis are not fenes- trated, but occasionally leaves are produced with up to two perforations, close to each other on the same side of the blade near its middle part. The measurements for the flowers of M. gambensis given above were taken from flower remnants of a single fruiting spadix, so they should be interpreted with caution. ACKNOWLEDGMENTS Marco Cedeño-Fonseca thanks the Organization for Tropical Studies for a Glaxo-Wellcome research grant and the Rexford Daubenmire fellowship, which supported fieldwork for the project “Taxonomy of the genus Monstera (Alismatales: Araceae) for Costa Rica”, and an Alwyn H. Gentry Fellowship from the Missouri Botanical Garden and a Mini-ARTS Fellowship from the Society of Systematic Biologists, which allowed him to study herbarium material at the Missouri Botani- cal Garden, the Marie Selby Botanical Gardens, and the New York Botanical Garden. Michael Mitter- meier, Cristina Goettsch Mittermeier, and Caroline Sparks also helped in raising funds for travel through a Gofundme.com campaign. Director Adam Karremans and the staff at the Jardín Botánico Lankester of Uni- versidad de Costa Rica are thanked for allowing the cultivation of living plants. Isler Chinchilla and Gus- tavo Rojas-Alvarado are thanked for their help in the field. Two anonymous reviewers are thanked for their insightful suggestions that greatly improved the manu- script. We are grateful to the Ministerio de Ambiente y Energía de Costa Rica (MINAE) and its Sistema Nacional de Áreas de Conservación (SINAC) for issu- Figure 6. Distribution of Monstera croatii (triangles), in Golfito and Corcovado National Park, and M. gambensis (circle), in Golfito, Costa Rica. 132 Marco Cedeño-Fonseca et al. ing the scientific permits under which wild specimens were collected. This contribution represents part of the Master’s thesis of Marco Cedeño-Fonseca, completed in the Programa de Posgrado en Biología at Universidad de Costa Rica. REFERENCES Cedeño-Fonseca MV. 2019. Revisión taxonómica del género Monstera (Araceae) en Costa Rica. Unpub- lished M.Sc. thesis, Programa de Posgrado en Biología, Sistema de Estudios de Posgrado, Universi- dad de Costa Rica, San José, Costa Rica. Cedeño-Fonseca M, Karremans AP, Ortíz OO. 2018. Monstera limitaris (Araceae), a new species from the border between Costa Rica and Panama. Phytotaxa 376: 37–42. Croat TB. 1992. Species diversity of Araceae in Colombia: a preliminary survey. Ann. Missouri Bot. Gard. 79: 17–28. Croat TB, Krömer T, Acebey A. 2010. Monstera florescanoana (Araceae), a new species from central Veracruz, Mexico. Revista Mex. Biodivers. 81: 225–228. Grayum MH. 2003. Araceae. Pp. 59–200 in, Hammel BE, Grayum MH, Herrera C, Zamora N, editors. Manual de Plantas de Costa Rica. Volumen II: Gimnosper- mas y Monocotiledóneas (Agavaceae–Musaceae). Monogr. Syst. Bot. Missouri Bot. Gard. 92: 1–694. Hay A. 2019. Durianology, discovery, and saltation: the evolution of aroids. Gard. Bull. Singapore 71 (Suppl. 2): 257–313. Jácome J, Croat TB. 2002. Notes on Monstera mini- ma Madison (Araceae) in Colombia and Panama. Aroideana 25: 60–62. Madison M. 1977. A revision of Monstera (Araceae). Contr. Gray Herb. 207: 3–100. Mayo SJ, Bogner J, Boyce PC. 1997. The genera of Arace- ae. Kew (UK): Royal Botanic Gardens. Ortiz OO, Croat TB, Baldini RM. 2018. Current status of aroid species diversity in Panama, including new records for the country. Webbia 73:141–153. Tam SM, Boyce PC, Upson TM, Barabé D, Bruneau A, Forest F, Parker JS. 2004. Intergeneric and infrafamil- ial phylogeny of subfamily Monsteroideae (Araceae) revealed by chloroplast trnL-F sequences. Amer. J. Bot. 91: 490–498. Zotz, G. 2013. ‘Hemiepiphyte’: a confusing term and its history. Ann. Bot. (Oxford) 111: 1015–1020. Zuluaga A, Llano M, Cameron K. 2019. Systematics, bio- geography and morphological character evolution of the hemiepiphytic subfamily Monsteroideae (Arace- ae). Ann. Missouri Bot. Gard. 104: 33–48. Vol. 75, n. 1 - 2020 Firenze University Press The impact of Covid-19 crisis on Plant Taxonomy: will we be able to approach to plant taxonomy as in the past? 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