Content uploaded by Mario A. Blanco
Author content
All content in this area was uploaded by Mario A. Blanco on Jul 15, 2020
Content may be subject to copyright.
Webbia. Journal of Plant Taxonomy and Geography 75(1): 123-132, 2020
Firenze University Press
www.fupress.com/webbia
WEBBIA
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 les.
Competing Interests: The Author(s)
declare(s) no conict of interest.
Editor: Peter C. Boyce
Two new endemic species of Monstera (Araceae:
Monsteroideae: Monstereae) from Golto in
southern Costa Rica
M C-F,*, A H, M H. G, M
A. B,,
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 Golto in the Pacic lowlands of southern Costa Rica. Notes are provided
on how they can be dierentiated 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 oor, and climbs only to a very limited height before owering.
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). ese
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 oen conspicuously perforated leaves (Grayum 2003; Cedeño-
Fonseca et al. 2018; Hay 2019). Molecular-phylogenetic analyses of subfamily
Monsteroideae agree in nding 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). e most recent
taxonomic revision (Madison 1977) recognized 22 species
in the entire genus. However, the rst 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.
e genus is currently divided into four sections
— Echinospadix Madison, Marcgraviopsis Madison,
Tornel i a (Gutiérrez ex Schott) Madison, and Monstera
(Madison 1977; Mayo et al. 1997; Croat et al. 2010) —
though it is doubtful whether this infrageneric classi-
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 eldwork in the forests of La
Gamba, Golto, 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 Golto, which only ascends on the pho-
rophyte to about 1.5 m above ground level. is 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, Golto 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-
d, peduncles with a persistent mucronate cataphyll, and
spadices with more or less spherical basal sterile owers.
Description
Moderately robust terrestrial herb to appressed nomadic
vine, owering 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 ow-
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 pinnatid 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 bid.
Inorescences on ascending shoots, 1–2 per owering
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 aer 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 ow-
ers slender, very conspicuous; sterile owers 3–5 mm
long, round with a very prominent stigmatophore; fertile
owers 5–6 mm long; stamens with laminar laments
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 aer 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-
125
Two new endemic species of Monstera (Araceae: Monsteroideae: Monstereae)
Figure 1. Monstera croatii. A. Developing inorescence. B. Front and back views of open inorescence. C. Fertile ower in lateral view (le)
and in longitudinal section (right). D. Stylar plate, top view (le), and individual stamen (right). E. Sterile ower in lateral view (le) 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. e 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 bid into lobules that divide up to 4 cm away from the costa
(arrow). Photographs: M. Cedeño-Fonseca.
127
Two new endemic species of Monstera (Araceae: Monsteroideae: Monstereae)
cies, previously identied as M. pinnatipartita Schott,
could represent a dierent, undescribed species.
Distribution and habitat
Monstera croatii is endemic to Costa Rica, where it is
known only from the south on the Pacic side in the
region of Golto and the Parque Nacional Corcovado
(both in the cantón of Golto) at ca. 300–600 m, in pri-
mary and secondary forest and in open areas (Figure 6).
Phenology
Immature infructescences recorded in February; ower-
ing observed in October and November.
Conservation status
Monstera croatii is protected in the Refugio Nacional de
Vida Silvestre Golto and in the Parque Nacional Cor-
covado.
Notes
Monstera croatii is dierentiated 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 dierentiated by the deeply pinnatid
and bluish green leaf blades, sometimes with bid 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 ower-
ing. Fertile terrestrial individuals were not found, but
one plant was observed fertile aer climbing only 50 cm
above ground level with the same stem and leaf mor-
phology as terrestrial examples.
Monstera croatii has sterile flowers with the ovary
spherical, as is also the case in M. glaucescens Croat
& Grayum, which too has glaucous stems and briey
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 aer signicantly 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, Golto, Golto, 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, Golto, Parque
Nacional Corcovado, Estación Agujas, Cerro Rincón,
8°31’34.467’’N, 83°28’3.9’’W, 600 m, 11 November 1999
(.), 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 diers 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 attened 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), oen 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.
129
Two 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. Inores-
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 ow-
ers 3–4 mm long; fertile owers 4–5 mm long; stamens
with laminar laments 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
e 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 Golto, 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, Golto. 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. e 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 Pacic 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. e 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.
131
Two 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. e 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. e measurements
for the owers of M. gambensis given above were taken
from ower 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 eldwork 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 sta 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
eld. 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 Golto and Corcovado National Park, and M. gambensis (circle), in Golto, Costa
Rica.
132 Marco Cedeño-Fonseca et al.
ing the scientic permits under which wild specimens
were collected. is 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. e 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.
