Epidendrum aromoense (Orchidaceae, Laeliinae), a New Species from the Coastal Dry Forests in Western Ecuador

Abstract

Epidendrum aromoense, a new epiphytic orchid found in very dry and seasonally foggy coastal forests, Manabi province, western Ecuador, is here described and illustrated. It is similar to Epidendrum tulcanense. It is characterized by the caespitose habit, simple stems, leaves oblong-lanceolate, coriaceous, bilobed and an elongate peduncle of the erect pluriracemose inflorescence, the flowers are red, the sepals about 9 mm long, the petals oblanceolate, the lip is square in outline, deeply 3-lobed, the lateral lobes dolabriform, the terminal lobe ending in a pair of divaricate, narrow, triangular acute, bifurcate teeth, the callus is orange, 5-tuberculate, ending in an acute, V-shape, keeled apex. This is the only red-flowered Epidendrum known from the lowlands of Ecuador. A conservation status of endangered, EN B1ab(iii), is provided for this species of great ornamental potential.

Full text

Epidendrum L. is one of the largest genera among
owering plants, encompassing over 1500 species in the
Neotropics (Hágsater, 1985). At present, ca. 400 species in
the genus have been recorded as to occur in Ecuador, being
210 (= 52 %) of those endemic to the country (Dodson in
Jørgensen & León, 1999; Valencia et al., 2011).
Red-owered species in Epidendrum are known for
having a distinctive distribution pattern in the Andes (e.g.,
the Elongatum subgroup; Hágsater, 2013); furthermore, no
species of the genus bearing red owers was previously
known from lowland Ecuador. During eld work in a
foggy, very dry, and disturbed coastal forest in the lowlands
of Manabí Province in western Ecuador, a red-owered
epiphytic Epidendrum with distinctive oral features called
our attention, and it is here described and illustrated as a
new species.
Epidendrum aromoense X. Cornejo & E. Hágsater, sp. nov.
TYPE: Ecuador. Manabí: El Aromo, a disturbed very dry
coastal forest, ca. 200 m, 7 March 2014 (), X. Cornejo,
M. Gallardo & V. Solórzano 8601 (holotype, GUAY; digital
photos at AMO, GUAY). Fig. 1–3.
Diagnosis: Similar to Epidendrum tulcanense Hágsater
& Dodson but the callus of the lip orange, concave within,
5-tuberculate, 2 globose processes, 2 outer, smaller at
growths, and an apical-V shaped protuberance like the bow
of a ship, the apex acute, versus the massive, white callus,
formed by nine unequal tubercles, four basal ones and the
main structure formed by ve sub-equal tubercles.
Epiphytic, caespitose, sympodial, erect herb, ca. 60 cm
tall. Roots 1–1.5 mm in diameter, eshy. Stems ca. 25 × 0.5
cm, simple, cane-like, terete, thin, straight. Leaves 7–12,
distributed throughout the stem, alternate, sub-erect; sheaths
1.5–2.1 × 0.4–0.5 cm, tubular, minutely striated when dry;
blade 5.5–8.5 × 1.4–2 cm, coriaceous, smooth, the lower
leaves lanceolate-oblong, the upper leaves oblong, about 3
to 5 times longer than wide, apex broadly obtuse at upper
leaves, slightly bilobed, margin entire. Spathe lacking.
Inorescence ca. 36 cm long, apical, racemose; peduncle
28.5 cm long, elongate, terete, thin, straight, nearly totally
covered by ca. 8 acute, tubular sheaths, 3.3–4.3 × 0.3
cm; rachis ca. 7.5 cm long, terete, thin. Flowers 30–40,
successive, ca. 18 open at one time, non-resupinate, red
(lacquer red), the callus orange (yellow in photos). Floral
bracts 1.5–4.5 mm long, much shorter than the ovary,
triangular-lanceolate, acuminate, gradually shorter towards
the apex of the rachis. Ovary 13–17 mm long, terete, thin,
arching towards the apex, smooth. Sepals ca. 9 × 3 mm,
spreading, free, elliptic, sometimes oblique, minutely
apiculate, 5-veined, margin entire, spreading. Petals 7–8
× 2 mm, spreading, free, oblanceolate, papillose, cuneate
towards the base, obtuse towards the apex, 4– to 5-veined.
EPIDENDRUM AROMOENSE (ORCHIDACEAE, LAELIINAE),
A NEW SPECIES FROM THE
COASTAL DRY FORESTS IN WESTERN ECUADOR
xavieR coRneJo1,2 anD eRic háGsateR3
Abstract. Epidendrum aromoense, a new epiphytic orchid found in very dry and seasonally foggy coastal forests, Manabi province,
western Ecuador, is here described and illustrated. It is similar to Epidendrum tulcanense. It is characterized by the caespitose habit,
simple stems, leaves oblong-lanceolate, coriaceous, bilobed and an elongate peduncle of the erect pluriracemose inorescence,
the owers are red, the sepals about 9 mm long, the petals oblanceolate, the lip is square in outline, deeply 3-lobed, the lateral lobes
dolabriform, the terminal lobe ending in a pair of divaricate, narrow, triangular acute, bifurcate teeth, the callus is orange, 5-tuberculate,
ending in an acute, V-shape, keeled apex. This is the only red-owered Epidendrum known from the lowlands of Ecuador. A conservation
status of endangered, EN B1ab(iii), is provided for this species of great ornamental potential.
Resumen. Describimos e ilustramos Epidendrum aromoense, una nueva especie de orquídea epíta que habita en los bosques muy
secos costeros y estacionalmente brumosos de la Provincia de Manabí, en el occidente de Ecuador. Es similar a Epidendrum tulcanense.
Se caracteriza por poseer un hábito cespitoso, tallos simples, hojas oblongo-lanceoladas, coriáceas, bilobadas, y una inorescencia erecta
con un pedúnculo alargado que porta una inorescencia pluriracemosa, las ores son rojas, los sépalos miden alrededor de 9 mm, los
pétalos son oblanceolados, el labio posee un contorno cuadrado, es profundamente 3-lobulado, los lóbulos laterales son dolabriformes,
el lóbulo terminal remata en un par de dientes divaricados, triangulares, agudos y bifurcados, el callo es naranja, posee 5 tubérculos y
remata en un ápice agudo, en forma de V, quillado. Esta es la única especie conocida de Epidendrum de ores rojas que habita en las
tierras bajas de Ecuador. Se provee el estatus de conservación en peligro, EN B1ab(iii), para esta especie de gran potencial ornamental.
Keywords: Epidendrum aromoense, Orchidaceae, coastal dry forest, Ecuador, endemic, IUCN Red List
The senior author whishes to thank Natalie Pyrooz, an associate eld researcher of the California Academy of Sciences, for the drawings of E. aromoense.
1 Herbarium GUAY, Facultad de Ciencias Naturales, Universidad de Guayaquil, Av. Juan Tanca Marengo y Las Aguas, Casilla 09-01-10634, Guayaquil,
Ecuador; xcornejoguay@gmail.com
2 Author for correspondence
3 Herbario AMO, Montañas Calizas 490, México, D.F. 11000, México; herbamo@prodigy.net.mx
Harvard Papers in Botany, Vol. 19, No. 2, 2014, pp. 185–188.
© President and Fellows of Harvard College, 2014.
ISSN: 1938-2944, DOI: 10.3100/hpib.v19iss2.2014.n3, Published online: 31 December 2014

fiGuRe 1. Epidendrum aromoense. A, epiphytic habit and disturbed habitat; B, stem and leaf bases; C, inorescence. Photograph by
X. Cornejo based on Cornejo et al. 8601 (GUAY), the holotype.
186 HARVARD PAPERS IN BOTANY VOL. 19, NO. 2

Lip 8–10 × 3–4 mm, united to the column, 3-lobed, base
deeply cordate, distal margins laciniate; callus concave
within, 5-tuberculate, 2 globose processes, 2 outer, smaller
at growths, and an apical-V shaped protuberance like the
bow of a ship, the apex acute; lateral lobes ca. 2 × 2 mm,
dolabriform; mid-lobe 3–4 × 4 mm, rather acutely dentate
to somewhat abellate, forming two divaricate lobes, apex
emarginate. Column 5 mm long, straight, thin, without
wings, papillose mainly towards the apex. Clinandrium
hood reduced, margin minutely dentate. Anther obovoid,
acute, 3-celled, densely papillose. Pollinia 3, ca. 0.8 × 0.2
mm, oblanceolate, elongate, laterally compressed, slightly
unequal, papillose. Rostellum apical, slit. Lateral lobes of
the stigma small. Nectary penetrating nearly 1/2 the ovary.
Capsule not seen.
Habitat and distribution: Known only from the
seasonally foggy very dry coastal forests of El Aromo
and Montecristi, located ca. 20 km apart from each other
in the Province of Manabí in western Ecuador, at ca. 200
m. The disturbed habitat in which Epidendrum aromoense
occurs is characterized by an annual average temperature
of 25˚C, annual average relative humidity of 78%, average
precipitation of 250 mm per year, and high exposure to
sun̓s UV rays (Weatherbase, 2014). In these harsh weather
conditions, the moisture provided by seasonal and nocturnal
fog undoubtedly plays a critical role in those xerophytic
areas allowing the establishment of populations of this
2014 CORNEJO AND HÁGSATER, A NEW EPIDENDRUM FROM WESTERN ECUADOR 187
as well as other epiphytic endemics such as the recently
described and sympatric Anthurium aromoense Croat
(Araceae), also collected by the rst author in the same area
(Croat et al., 2013).
Conservation status: The localities where Epidendrum
aromoense does occur are threatened by the advance of
agricultural frontier or forest conversion to cattle farms
and other land use. Therefore, the status of endangered, EN
B1ab(iii) (IUCN, 2001) is assigned to this species.
Uses: Epidendrum aromoense as well as another recently
described species from the same habitat, Anthurium
aromoense, become adapted in cultivation with little care
within few weeks. These species have been successfully
planted as ornamentals by the senior author in hot and
humid cities such as Manta and Guayaquil.
Phenology: Epidendrum aromoense has been observed
with owers during February and March. It is unknown if
owers are also produced during some of the remaining
months of the year.
Etymology: The specic epithet refers to El Aromo, the
locality where the new species was found.
Paratypes: ECUADOR. Manabí: Slopes of Montecristi,
L. Besse 134 (QCA, SEL); same locality, C. Luer 1472
(SEL). Specimens seen but not studied in detail.
The type specimen had only three pollinia, which is
unusual for this group of species, the normal number being
four. The authors were not able to study this character in the
proposed paratypes.
Epidendrum aromoense belongs to the Secundum group,
Elongatum subgroup which is recognized by the caespitose
habit, simple stems, leaves oblong-lanceolate, coriaceous,
bilobed and elongate peduncle of the erect, pluriracemose
inorescence, the owers non-resupinate, the callus
complicated, plurituberculate. The species is recognized by
the successive, lacquer-red owers, the orange callus, sepals
about 9 mm long, the petals somewhat smaller than the
sepals, oblanceolate, the lip square in outline, deeply 3-lobed,
the lateral lobes dolabriform, terminating in a pair of
divari-cate, narrow, triangular, acute, bifurcate teeth, the
lateral lobes clearly separate and never overlapping with
the mid-lobe when spread, and the mid-lobe rather acutely
dentate to somewhat abellate, bilobed and distinctively
divaricate; callus concave within, 5-tuberculate, 2 globose
processes, 2 outer, smaller at growths, and an apical-V
shaped protuberance like the bow of a ship, the apex acute.
fiGuRe 3. Epidendrum aromoense. Column, callus, and lip, lateral
view (sepals and petals removed). Drawing by Natalie Pyrooz
based on Cornejo et al. 8601 (GUAY), the holotype.
fiGuRe 2. Epidendrum aromoense. Floral segments, adaxial view.
Drawing by Natalie Pyrooz based on Cornejo et al. 8601 (GUAY),
the holotype.

188 HARVARD PAPERS IN BOTANY VOL. 19, NO. 2
The distinctive pattern of distribution, that is, restricted to
the lowlands of central-western Ecuador (versus Andean)
makes an easy differentiation for E. aromoense in
comparison to the remaining red-owered species in the
subgroup. Similar red-owered species are: Epidendrum
tulcanense Hágsater & Dodson has also red owers but
it is distinguished by the large white massive callus,
formed by nine unequal tubercles: four basal ones and
the main structure formed by ve sub-equal tubercles.
Epidendrum laurelense Hágsater & Dodson, that differ
from E. aromoense by the carmine-red owers on a much
more open raceme, with a massive white callus formed
by a semicircular sulcate, marginally plurilobulate eshy
plate, found between Tulcán and Maldonado, on the border
between Ecuador and Colombia, on roadsides and rocks in
wet forest between at around 2000 to 2500 m above sea level.
Epidendrum coroicoënse Schltr. is another species similar
to E. aromoense by the lacquer-red owers; however, the
former species is known from southern Peru and western
Bolivia, along the upper Amazon slope of the Cordillera
Oriental of the Andes, and differ from E. aromoense by
the narrow leaves about 6–7 times longer than wide, the
petals wider than the sepals, elliptic-sub-orbicular, the
lip bearing lateral lobes overlapping with the mid-lobe
when spread; and callus 5-tuberculate with two basal and
three apical tubercles, and without keels. Epidendrum
portokalium Hágsater & Dodson is another species with red
owers that resembles E. aromoense, but it is found on the
Amazon slopes of the Andes in central Ecuador, and differs
from E. aromoense by the callus unequally 7-tuberculed
(with four basal tubercles and three apical ones).
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