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Mt. Banahaw reveals: The resurrection and neotypification of the name Rafflesia lagascae (Rafflesiaceae) and clues to the dispersal of Rafflesia seeds

Authors:
Pieter B. Pelser at University of Canterbury
Pieter B. Pelser
Daniel Lee Nickrent at Southern Illinois University Carbondale
Daniel Lee Nickrent
John Rey Callado
John Rey Callado
Julie F Barcelona at University of Canterbury
Julie F Barcelona
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Abstract and Figures

The southeast Asian holoparasite genus Rafflesia Brown (1821: 207; Rafflesiaceae) is famous for producing the largest flowers on record (Kuijt 1969). Following a series of discoveries of new Rafflesia species and populations, the Philippines recently emerged as one of the centers of its diversity. It is home to no less than ten currently recognized Rafflesia species (Barcelona et al. 2009, Balete et al. 2010). Here, we report two discoveries that resulted from recent fieldwork in the Mts. Banahaw - San Cristobal Protected Landscape in Luzon and show how these new data impact the taxonomy and biology of Philippine Rafflesia.
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Accepted by Benjamin vanEe: 28 Aug. 2013; published: 13 Sept. 2013
35
PHYTOTAXA
ISSN 1179-3155 (print edition)
ISSN
1179-3163 (online edition)
Copyright © 2013 Magnolia Press
Phytotaxa 131 (1): 35–40 (2013)
www.mapress.com
/phytotaxa/
Correspondence
http://dx.doi.org/10.11646/phytotaxa.131.1.6
Mt. Banahaw reveals: The resurrection and neotypification of the name Rafflesia
lagascae (Rafflesiaceae) and clues to the dispersal of Rafflesia seeds
PIETER B. PELSER
1
, DANIEL L. NICKRENT
2
, JOHN REY C. CALLADO
3
& JULIE F. BARCELONA
1
1
School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand;
email: pieter.pelser@canterbury.ac.nz, julie.barcelona@canterbury.ac.nz.
2
Department of Plant Biology, Southern Illinois University Carbondale, 1125 Lincoln Drive, Carbondale, IL 62901-6509, USA.
3
Philippine National Herbarium (PNH), Botany Division, National Museum of the Philippines, P. Burgos St., Manila, Philippines.
The southeast Asian holoparasite genus Rafflesia Brown (1821: 207; Rafflesiaceae) is famous for producing
the largest flowers on record (Kuijt 1969). Following a series of discoveries of new Rafflesia species and
populations, the Philippines recently emerged as one of the centers of its diversity. It is home to no less than
ten currently recognized Rafflesia species (Barcelona et al. 2009, Balete et al. 2010). Here, we report two
discoveries that resulted from recent fieldwork in the Mts. Banahaw - San Cristobal Protected Landscape in
Luzon and show how these new data impact the taxonomy and biology of Philippine Rafflesia.
Resurrection and neotypification of the name Rafflesia lagascae (Rafflesiaceae)
Rafflesia manillana Teschemacher (1844: 65) was originally described from the island of Samar in the
Philippines, but until recently, extant populations by this name were only known from Luzon. In 2007,
however, Madulid et al. (2008) found a Rafflesia population on Samar. This population was located in the
municipality of Basey, which is the general area where the type of R. manillana was originally collected. This
type specimen was a set of three flower buds and is presumed lost (Madulid & Agoo 2008; Barcelona et al.
2009). Upon inspection of flowers from the Samar population, Madulid et al. (2008) concluded that these
plants belong to a different species than the Luzon populations referred to as R. manillana. They subsequently
described these Luzon populations as R. panchoana Madulid, Buot & Agoo (2008: 44), maintaining the name
R. manillana only for the population of plants from Samar. Barcelona et al. (2009) did not follow Madulid et
al. (2008) in recognizing the Luzon and Samar Rafflesia as distinct species. They pointed out that the
characters that were used by Madulid et al. (2008) to distinguish the two species are quite variable in the
Luzon populations and overlap with those reported from Samar. Furthermore, they concluded that
examination of more open flowers would be needed to confirm that the characters used by Madulid et al.
(2008) are consistent across individuals and populations.
In 2011 Barcelona visited the Samar population and was able to study many fresh flowers. This confirmed
the overlap in most character states between the Luzon and Samar flowers that Madulid et al. (2008) listed as
features distinguishing the two species. As discussed by Barcelona et al. (2009), many of these characters are
correlated with flower size. However, two characters indeed show consistent morphological differences,
although these are perhaps not as discrete as is suggested by Madulid et al. (2008): the diaphragm color, and
the relative size of the diaphragm aperture (Fig. 1). Rafflesia flowers from Luzon (Fig. 1A) have bicolored
diaphragms of which either the speckles or the background is concolorous with the perigone lobes. In
contrast, flowers from Samar (Fig. 1B) have whitish diaphragms, similar to those seen in R. lobata Galang &
Madulid (2006: 2). Moreover, flowers from Luzon typically have a much wider diaphragm aperture (i.e.
considerably wider than the diameter of the disk) than those from Samar. These morphological differences,
together with the disjunct distribution of the Luzon and Samar populations, may indicate a current absence of
gene flow between them, and that they merit taxonomic recognition as different species under a biological
species concept (Mayr 2000).
PELSER ET AL.36 • Phytotaxa 131 (1) © 2013 Magnolia Press
Barcelona et al. (2009) argued that if the Luzon populations previously known as R. manillana indeed
represent a species distinct from the R. manillana populations on Samar, an earlier name, R. lagascae Blanco
(1845: 595), is available for the Luzon taxon, as opposed to the name R. panchoana. Rafflesia lagascae is one
of two Rafflesia species that Blanco (1845) described from Mt. Banahaw; the second being R. philippensis
Blanco (1845: 565). Most likely because Blanco did not preserve the specimens that he studied, and because
Rafflesia was no longer reported from Mt. Banahaw in the remainder of the 19
th
and 20
th
centuries, both names
were considered synonyms of R. manillana by later authors (e.g., Solms-Laubach 1891, 1901, Brown 1912,
Merrill 1923, Meijer 1997, Nais 2001).
In 2007, two separate teams of researchers, Barcelona et al. (2007) and Madulid et al. (2007) reported
Rafflesia plants on Mt. Banahaw that were morphologically distinct from those known as R. manillana
elsewhere in Luzon. The name R. philippensis was subsequently resurrected for these plants (Barcelona et al.
2009; Fig. 2A). Here, we report the finding of a second species of Rafflesia at the foot of Mt. Bananaw. This
species is conspecific with the Luzon populations previously known as R. manillana. This discovery confirms
that Blanco was correct in recognizing two distinct Rafflesia species in the area. In addition, it provides
further support for the conclusion that his R. lagascae is the earlier and valid name for R. panchoana. Because
the type specimen of R. lagascae collected by Azaola and presented to Blanco was not preserved, we
designate Barcelona 3819 with Pelser (CHR) as the neotype for this species:
Rafflesia lagascae Blanco (1845: 595; Fig. 1A)
Type:—PHILIPPINES. Luzon: Monte de Majaijai (Mt. Banahaw), 22 April 1840 (fide Solms-Laubach 1891), Azaola
s.n. (not preserved). Neotype (designated here):—PHILIPPINES. Luzon: Quezon Prov., Dolores Municipality,
Barangay Kinabuhayan, Bangkong Kahoy Valley, Mts. Banahaw – San Cristobal Protected Landscape, 14°2’56" N,
121°26'35"E, ca. 700 m, 3 April 2013, Barcelona 3819 with Pelser (CHR).
= Rafflesia panchoana Madulid, Buot & Agoo (2008: 44). Type:—PHILIPPINES. Luzon: Laguna Prov., Mt. Makiling,
1914, W.H. Brown s.n. (Species Blancoanae 535) (holotype: US904212).
Clues to the dispersal of Rafflesia seeds
In addition to rediscovering Mt. Banahaw’s second Rafflesia species, our fieldwork has contributed data that
may help resolve a long-standing secret about the life cycle of Rafflesia: the mode of seed dispersal. Rafflesia
fruits produce thousands of tiny seeds (ca. 0.5–0.75 x 0.3 mm) in leathery, dome-shaped, indehiscent berries
(Fig. 2B–D). These appear to rely on the destruction or decay of the fruit wall for the seeds to be dispersed
(Kuijt 1969). A wide variety of animals have been considered as potential dispersers of Rafflesia seeds
ranging from ants and termites to elephants, mice, pigs, and termite predators (Teijsmann 1856, Justesen
1922, Kuijt 1969, Nais 2001). To our knowledge, direct observations of seed dispersal have thus far only been
reported by Emmons et al. 1991, who observed a treeshrew (Tupaia tana) and squirrel (Callosciurus notatus)
feeding on Rafflesia fruits.
In November 2011, we encountered a fruit of R. philippensis in an advanced state of decay. After
removing some of the decaying fruit wall, we noticed the presence of numerous ants (Technomyrmex sp. and
Pheidologeton sp.) among the disintegrating tissue. Several of these ants were carrying Rafflesia seeds away
from the fruit (Fig. 2E–H). This discovery fits in well with Kuijt’s (1969) hypothesis that the chalazal swelling
of Rafflesia seeds (giving them the shape of a two-seeded peanut; Fig. 2D) might be an elaiosome. Elaiosomes
are characteristic oily appendages on seeds of myrmecochorous plants, such as arils, crests, etc. that offer food
bodies to ants (Jackson 1960). It certainly seems plausible that ants, attracted to a nutritious elaiosome, would
transport these seeds to their nests. There, they might germinate and infect the roots of a nearby vine of
Tetrastigma (Miquel 1863: 72) Planchon (1887: 423; Vitaceae; the only known host genus of Rafflesia).
Infection most likely takes place in the underground parts of Tetrastigma (Justesen 1922), because although it
is not uncommon to see Rafflesia buds and flowers emerging from the climbing parts of a Tetrastigma vine, all
Rafflesia species flower primarily at ground level. This finds some support from Teijsmann’s (1856)
experiments in which he successfully infected Tetrastigma by inserting Rafflesia seeds into slits that he cut in
its roots. Although it is entirely unknown how Rafflesia infects Tetrastigma in natural conditions, it is possible
Phytotaxa 131 (1) © 2013 Magnolia Press • 37
MT. BANAHAW REVEALS
that this involves a mycorrhizal partner, as is observed in other holoparasitic plants with miniscule seeds, such
as Conopholis americana (Linnaeus 1767: 88) Wallroth (1825: 78) (Baird & Riopel 1986). Even though we
were not able to locate and excavate the ant nest and confirm the presence of Tetrastigma roots and/or
Rafflesia seedlings, our discovery revitalizes the ant-dispersal hypothesis. Detailed field studies are needed to
explore this further.
FIGURE 1. A. Rafflesia lagasacae, Mt. Banahaw, Luzon, Philippines; Barcelona 3819 with Pelser (neotype, CHR). B. Rafflesia
manillana, Samar Island Natural Park (SINP), Sitio Bagong Silang, Brgy. Guirang, Basey, Samar, Philippines. Photographs taken by
Pelser & Barcelona.
PELSER ET AL.38 • Phytotaxa 131 (1) © 2013 Magnolia Press
FIGURE 2. A–H. Rafflesia philippensis, Mt. Banahaw, Luzon, Philippines. A. Flower, Barcelona 3809 with Pelser (CANU). B–D.
Nearly mature fruit. B. Cross section of fruit. C. Seeds, 1 mm scale. D. Seeds. E–H. Ants (Technomyrmex sp. (F) and Pheidologeton
sp. (E, G, H)) carrying seeds (indicated with white arrows) from a decaying fruit. Photographs taken by Pelser & Barcelona.
Phytotaxa 131 (1) © 2013 Magnolia Press • 39
MT. BANAHAW REVEALS
Acknowledgements
We are grateful to the people of Barangay Kinabuhayan, Dolores, Quezon, especially Kagawad Jerry R.
Mendua, Ananias (Dingdong) M. Cahilo Sr., Richard (Bebot) Manao, Brgy. Captain Romeo R. Diala, ex-
Barangay Captain and Mrs. Angeles Coronado, the Protected Area Management Board (PAMB), Mts.
Banahaw – San Cristobal Protected Landscape and Protected Area Superintendent (PASu) Salud Pangan. For
field assistance in Samar Island National Park (SINP), we thank Guirang ex- Barangay Captain Ignacio
Gimbaolibot, Wilfredo G. Depalco, Judah Aliposa, and staff of DENR Region 8, namely, Eires M. Mate, Felix
D. Bernal, Paquito P. Dabuet, and Allan C. Reyna. Matt Walters prepared the ant and seed photos for
publication. Perry Archival C. Buenavente provided taxonomic identifications for the ants. This project was
supported by the National Geographic Society and the Marsden Fund Council from Government funding,
administered by the Royal Society of New Zealand.
References
Baird, W.V. & Riopel, J.L. (1986) The developmental anatomy of Conopholis americana (Orobanchaceae) seedling and
tubercles. Canadian Journal of Botany 64: 710–
717.
http://dx.doi.org/10.1139/b86-090
Balete, D.S., Pelser, P.B., Nickrent, D.L. & Barcelona, J.F. (2010) Rafflesia verrucosa (Rafflesiaceae), a new species of
small-flowered Rafflesia from eastern Mindanao, Philippines. Phytotaxa 10: 49–57.
Barcelona, J.F., Pelser, P.B. & Cajano, M.O. (2007) Rafflesia banahaw (Rafflesiaceae), a new species from Luzon,
Philippines. Blumea 52: 345–
350.
http://dx.doi.org/10.3767/000651907x609089
Barcelona, J.F., Pelser, P.B., Balete, D.S. & Co, L.L. (2009) Taxonomy, ecology, and conservation status of Philippine
Rafflesia. Blumea 54: 77–
93.
http://dx.doi.org/10.3767/000651909x474122
Blanco F.M. (1845) Flora de Filipinas, ed. 2. M. Sanchez, Manila, 619 pp.
Brown, R. (1821) An account of a new genus of plants, named Rafflesia. Transactions of the Linnean Society of London
13: 201–234.
http://dx.doi.org/10.1111/j.1095-8339.1821.tb00062.x
Brown, W.H. (1912) The relation of Rafflesia manillana to its host. The Philippine Journal of Science. C. Botany 7: 209–
226.
Emmons, L.H., Nias, J. & Briun, A. (1991) The fruit and consumers of Rafflesia keithii (Rafflesiaceae). Biotropica 23:
197–199.
http://dx.doi.org/10.2307/2388307
Galang, R. & Madulid, D.A. (2006) A second species of Rafflesia (Rafflesiaceae) from Panay Island, Philippines. Folia
Malaysiana
7: 1–8.
http://dx.doi.org/10.2307/4110994
Jackson, B.D. (1960) A glossary of botanic terms with their derivations and accent. Gerald Duckworth & Co. Ltd.,
London, 481 pp.
Justesen, P.T. (1922) Morphological and biological notes on Rafflesia flowers observed in the highlands of mid-Sumatra.
Annales du Jardin Botanique de Buitenzorg 32: 64–87.
Kuijt, J. (1969) The biology of parasitic flowering plants. University of California Press, Berkeley and Los Angeles, 246
pp.
Linnaeus, C. 1767. Mantissa plantarum 1. Laurentius Salvius, Stockholm. 142 pp.
Madulid, D.A., Villariba-Tolentino, C. & Agoo, E.M.G. (2007 [2006]). Rafflesia banahawensis (Rafflesiaceae), a new
species from Luzon, Philippines. Philippine Scientist
43: 43–51.
http://dx.doi.org/10.3860/psci.v43i0.370
Madulid, D.A. & Agoo, E.M.G. (2008 [2007]) On the identity of Rafflesia manillana Teschem. (Rafflesiaceae).
Philippine Scientist 44: 57–
70.
http://dx.doi.org/10.3860/psci.v44i0.379
Madulid, D.A., Buot, I.E. & Agoo, E.M.G. (2008 [2007]) Rafflesia panchoana (Rafflesiaceae), a new species from
Luzon island, Philippines. Acta Manilana 55: 43–
47.
http://dx.doi.org/10.3860/acta.v55i0.1485
PELSER ET AL.40 • Phytotaxa 131 (1) © 2013 Magnolia Press
Mayr, E. (2000) The biological species concept, in: Wheeler, Q.D. & Meier, E. (eds.) Species concepts and phylogenetic
theory: a debate. Columbia University Press, New York, pp. 17–29.
Meijer, W. (1997) Rafflesiaceae. Flora Malesiana, Series 1 13: 1–42.
Merrill E.D. (1923) An enumeration of Philippine flowering plants Vol. 2. Bureau of Printing, Manila, 530 pp.
Miquel, F.A.W. (1863) Ampelideae novae. Annales Museum Botanicum Lugduno-Batavi 1: 72–101.
Nais, J. (2001) Rafflesia of the world. Sabah Parks, Kota Kinabalu, 260 pp.
Planchon, J.E. (1887) Ampelideae, in: De Candolle, A.L.P.P. & De Candolle, A.C. (eds.) Monographiae
phanerogamarum 5. Paris, pp. 305–637.
Solms-Laubach, H. (1891) Ueber die Species in der Gattung Rafflesia insonderheit ueber die auf dem Philippinen sich
findenden Arten. Annales du Jardin Botanique de Buitenzorg 9: 184–246.
Solms-Laubach, H. (1901) Rafflesiaceae. Das Pflanzenreich 4: 1–18.
Teijsmann, J.E. (1856) Nadere bijdrage tot de kennis van de voortteling van Rafflesia arnoldii R.Br. in 's Lands
Plantentuin te Buitenzorg. Natuurkundig Tijdschrift voor Nederlands Indië 12: 277–281.
Teschemacher, J.E. (1844) On a new species of Rafflesia, from Manilla. Boston Journal of Natural History 4: 63–66.
Wallroth, C.F.W. (1825) Orobanches generis diaskene. Fredericus Wilmans, Frankfurt, 80 pp.
... Pelser et al. (2019) suggested that if the high island endemism of Rafflesia is not a result of island-level extinction or a gap in our knowledge of their current distribution, it might be a result of poor interisland dispersibility because the results of their molecular phylogenetic and biogeographic analyses indicated that dispersal of Philippine Rafflesia between islands was relatively uncommon in their evolutionary history. Ants may be the primary seed dispersers of Rafflesia (Pelser et al., 2013(Pelser et al., , 2018. Because ants typically do not transport seeds farther than 10-80 m (Gómez and Espadaler, 1998;Vittoz and Engler, 2007) and large bodies of water are assumed to be a significant barrier for myrmecochory, Rafflesia seeds might only be very rarely dispersed between islands. ...
... We recorded all occurrence points of these Rafflesia species and their Tetrastigma host species using Garmin GPS units during fieldwork throughout the Philippines between 2007 and 2018, as part of previous Rafflesia and Tetrastigma research projects (e.g., Barcelona et al., 2009;Pelser et al., 2013Pelser et al., , 2016Pelser et al., , 2017Pelser et al., , 2018Pelser et al., , 2019Obico et al., 2021aObico et al., , 2021b. Duplicates were removed, and spatial thinning was implemented to retain only one occurrence point in every 30 arcsec grid cell (i.e., the highest resolution at which bioclimatic data are available from CHELSA, see below; equivalent to~1 km 2 at the equator) to avoid spatial sampling bias (i.e., unequal sampling effort resulting in a biased Maxent model; Kramer-Schadt et al., 2013). ...
... Blanco (Blanco, 1845;Barcelona et al., 2008;Pelser et al., 2013Pelser et al., , 2019Galindon et al., 2016). ...
What explains the high island endemicity of Philippine Rafflesia? A species distribution modeling analysis of three threatened parasitic plant species and their hosts
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  • Dec 2023
  • AM J BOT
Premise: Rafflesia are rare holoparasitic plants. In the Philippines, all but one species are found only on single islands. This study aimed to better understand the factors contributing to this distribution pattern. Specifically, we sought to determine whether narrow environmental tolerances of host and/or parasite species might explain their island endemicity. Methods: We used Maxent species distribution modeling to identify areas with suitable habitat for R. lagascae, R. lobata, and R. speciosa and their Tetrastigma host species. These analyses were carried out for current climate conditions and two future climate change scenarios. Key results: Although species distribution models indicated suitable environmental conditions for the Tetrastigma host species in many parts of the Philippines, considerably fewer areas are inferred to have suitable conditions for the three Rafflesia species. Some of these areas are found on islands from which they have not been reported. All three species will face significant threats as a result of climate change. Conclusions: Our results suggest that limited inter-island dispersal abilities and/or specific environmental requirements are likely responsible for the current pattern of island endemicity of the three Rafflesia species, rather than environmental requirements of their Tetrastigma host species. This article is protected by copyright. All rights reserved.
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... The Rafflesia spp. on Luzon Island have been particularly confused, despite nearly a century and a half of botanical exploration in the region. For example R. banahawensis Madulid, Villariba-Tolentino & Agoo [as R. philippensis in Barcelona et al. 2009b;Blanco 1845] in the mountains of the Banahaw-San Cristobal Protected Landscape (Barcelona et al. 2008b;Madulid et al. 2006;Pelser et al. 2013) and R. panchoana Madulid, Buot & Agoo in the Mount Makiling Forest reserve (Madulid et al. , 2012 [as R. manillana in Fernando & ong 2005a; as R. lagascae in Barcelona et al. 2009cBarcelona et al. , 2011Pelser et al. 2013] were both overlooked until recently, and synonymised under R. manillana, a distinct species from Basey, Samar Island . This confusion emphasizes the need for a concerted and coordinated effort to explore and define species limits in the region. ...
... The Rafflesia spp. on Luzon Island have been particularly confused, despite nearly a century and a half of botanical exploration in the region. For example R. banahawensis Madulid, Villariba-Tolentino & Agoo [as R. philippensis in Barcelona et al. 2009b;Blanco 1845] in the mountains of the Banahaw-San Cristobal Protected Landscape (Barcelona et al. 2008b;Madulid et al. 2006;Pelser et al. 2013) and R. panchoana Madulid, Buot & Agoo in the Mount Makiling Forest reserve (Madulid et al. , 2012 [as R. manillana in Fernando & ong 2005a; as R. lagascae in Barcelona et al. 2009cBarcelona et al. , 2011Pelser et al. 2013] were both overlooked until recently, and synonymised under R. manillana, a distinct species from Basey, Samar Island . This confusion emphasizes the need for a concerted and coordinated effort to explore and define species limits in the region. ...
The reinstatement of Rafflesia banaoana (Rafflesiaceae), and implications for assessing species diversity and conservation requirements of the world's largest flowers
Article
  • Sep 2023
The Southeast Asian genus Rafflesia (rafflesiaceae) is famous for possessing the world's largest flowers. All species are rare or threatened, so understanding taxonomic diversity in the genus is crucial for informing effective conservation practice. here we examine R. banaoana, a poorly known taxon from the remote montane rainforests of the Kalinga Province in the Philippines. This species has been treated as conspecific with R. leonardi, and overlooked in systematic studies. Using stable yet hitherto neglected features such as the stigmatic fascia surface, disk shape, process structure, annulus interior and exterior distinction, and ovary shape, we demonstrate that R. banaoana is morphologically as well as ecologically distinct from R. leonardi, and requires reinstatement at the specific rank. We present our findings in the broader context of complexity in the genus Rafflesia in the Philippines, now considered the center of diversity, with 15 species described to date. We highlight the taxonomically confused R. banaoana as a case for careful observation of previously unexamined morphological characters , as well as ecology, to avoid overlooking cryptic taxa or species complexes and to inform representative sampling in systematic treatments. Such an approach will be essential for enhancing our understanding of the diversity of this enigmatic yet poorly understood genus at a time of unprecedented anthropogenic change and species extinction. In light of our findings, we recommend a holistic approach to the conservation of Rafflesia in the Philippines.
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... The genus Rafflesia (Raflesiaseae) is composed of parasitic plants that produce what are known to be the giants among flowers (Barcelona et al. 2006;Pelser et al. 2013). The plants are entirely dependent on Tetrastigma (Vitaceae) vines that grow mainly in lowland forests. ...
... The species has also been included as early as 1986 by Tan et al. among endangered Philippine plants. After a thorough study by Pelser et al. (2013), the Makiling population, locally called "malaboô," is now properly known as R. lagascae Blanco. Endemic to Luzon, it is now the most widely distributed among the Philippine Rafflesia from Cagayan Province in the north to Albay Province in the south (Barcelona et al. 2018). ...
Records of floral visitation by dipterans on malaboô, Rafflesia lagascae Blanco (Rafflesiaceae), mainly in Mount Makiling, Laguna, Philippines
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Full-text available
  • Apr 2018
Floral visitors of Rafflesia lagascae Blanco are identified and recorded as actual or potential pollinators. The most commonly observed was the metallic blue blow fly, Chrysomya megacephala (Fabricius), while two other blow flies, observed but not collected include a dull-colored, bristly species that probably belongs to Bengalia, and the greenish-blue species Lucilia fumicosta Malloch. The red-eyed flesh fly, Sarcophaga sp., was also observed to visit and possibly larviposits some of its tiny maggots into the perigone. The common housefly, Musca domestica L., vinegar flies Drosophila spp., and undetermined dolichopodids and phorids were also observed. The phorids probably play a greater role toward the decay of the more matured flowers. Video-documentation and other field studies are recommended for this threatened Rafflesia species in a forest reserve that has witnessed a recent rise in tourist visits.
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... The flowers emit odors that attract carrion flies for pollination. Successful pollination results in a fruit that sheds millions of seeds with seed dispersal possibly facilitated by small mammals and ants [52,59]. ...
Microbes and metabolites of a plant-parasite interaction: Deciphering the ecology of Tetrastigma host choice in the world’s largest parasitic flower, Rafflesia
Article
Full-text available
  • Feb 2025
Rafflesia, known for producing the world’s largest flowers, is a holoparasite found only in Southeast Asia's rapidly diminishing tropical forests. Completely dependent on its Tetrastigma host plants, Rafflesia grows covertly within its host until flowering, but the ecological factors driving host susceptibility are unknown. With most Rafflesia species on the brink of extinction due to habitat loss, understanding the complex ecological interactions between Rafflesia and its host is crucial for conservation. In this study, we integrated metagenomic data with metabolomic profiles to identify potential functional relationships between microbial communities and specific metabolites, shedding light on their ecological roles in Rafflesia's life cycle. Key findings reveal that microbial taxa such as Microbacteriaceae and Nocardioidaceae correlate with elevated levels of polyphenols, particularly gallic acid derivatives, which may shape the chemical environment conducive to Rafflesia development. Complex-carbon-degrading bacteria thrive in the chemically distinct environment of Rafflesia buds, while an unknown group of Saccharimonadales was enriched in Tetrastigma host species. Docosenamide production in Rafflesia buds and their hosts may facilitate parasitic infection, while coumarin compounds in non-host Tetrastigma species may exert allelopathic effects. The enrichment of gallic acid derivatives, the phytohormone adenine, and gall-associated bacteria suggests that Rafflesia buds may function similarly to plant galls, manipulating host tissues to support their reproductive development. This study highlights the dynamic microbial shifts during Rafflesia’s development, emphasizing its symbiotic relationship with microbial communities and hosts. In identifying essential microbial and chemical conditions that could improve propagation techniques, this research has practical applications in ex situ conservation efforts, aiding in the rescue of the world’s largest flowers from the brink of extinction.
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... The flowers emit odors that deceptively attract carrion flies for pollination. Successful pollination results in a fruit that sheds millions of seeds with seed dispersal possibly facilitated by small mammals and ants (Nais 2001;Pelser et al., 2013). ...
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... Researchers assume that rodents feed on the fruit and excrete seeds near host vines. Ants may also carry and disperse seeds ( 3 ). But only certain species of Tetrastigma vines support Rafflesia blooms, and what sets hosts apart isn't known. ...
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... Unique characteristics are shown for the species R. consueloae, R. baletei, R. aurantia, R. lobata, R. manillana, R. lagascae, and R. philippensis as indicated on the phylogenetic tree. Moreover, the R. manillana and R. lagascae were put together in one branch as they were previously considered as synonyms due to their mostly similar morphological characteristics (Pelser, Nickrent, Callado, & Barcelona, 2013). While for the R. speciosa and R. mira, they have the same initial size and closely related final size when it comes to floral diameter. ...
Assessment on the Phylogenetic Position of Rafflesia aurantia with the Endemic Rafflesia Species in the Philippines
Article
Full-text available
  • Oct 2021
Rafflesia aurantia is the most recently discovered Rafflesia that can be found on the Philippines which makes it the only species to not have a phylogenetic position in the phylogenetic tree of the endemic Rafflesia species in the Philippines. The study seeks to provide an analysis on the closest relative of Rafflesia aurantia with the endemic Rafflesia species in the Philippines. Specifically, the study aims to reassess the phylogenetic relationship of Rafflesia aurantia with the endemic rafflesia species in the Philippines in terms of its molecular data and morphoanatomy. The researchers formulated phylogenetic hypotheses on the construction of a new tree that specifies where Rafflesia aurantia is placed on the proposed phylogenetic tree. The researchers used a descriptive quantitative approach to this study and the data gathered were collected through a bibliographic technique and molecular data were gathered from GenBank. The collected FASTA format of nucleotide sequences of the twelve Rafflesia species were placed in the MEGA software with a bootstrap of 100. Significant relationship among species was found even though morphology and molecular analysis are both different factors. This is due to the avoidance of gamete wastage and hybridization which are coping mechanisms of the Rafflesia in order to conserve gene even with the ecological condition. It is found out that using morphological assimilation on determining the phylogenetic position of Rafflesia species are closely correlated to the phylogenetic tree constructed using molecular data of the different species. The data showed that Rafflesia aurantia belongs in the clade between Rafflesia baletei and Rafflesia lobata in terms of its morphology. Since DNA sample of Rafflesia aurantia is not yet available, it is recommended for future researchers to further prove and solidify the proposed position Rafflesia aurantia among the phylogenetic tree of Rafflesia species. Keywords: Rafflesia aurantia, endemic rafflesia species, Philippine rafflesia
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... Fruits may take four to eight months to mature and ripen depending on species (Beaman and Adam 1984;Meijer 1997;Tolod et al. 2021;Whitten et al. 1996). Fruit herbivory and damage by animals may help seed dispersal and inoculation on the roots and stems of Tetrastigma hosts (Bänziger 1991;Bouman and Meijer 1994;Justesen 1922;Meijer 1958;Nais 2001;Pelser et al. 2013;Tolod et al. 2021). In this study, ants were seen visiting the fruit damaged by animals. ...
Bud development, flower phenology and life history of holoparasitic Rafflesia cantleyi
Article
Full-text available
  • Feb 2024
  • J PLANT RES
Despite being the world's largest single-flower, Rafflesia’s biology and life history are still poorly understood due to its cryptic growth strategy on Tetrastigma vines. Previous studies have been mostly short-term, contrary to Rafflesia’s long development period before blooming. Bud development and flower phenology of R. cantleyi was studied in a dipterocarp forest in Lata Jarum, Peninsular Malaysia. Seven populations, consisting of 247 buds, were monitored fortnightly for 65 months in two discrete studies between 2009 and 2018. The bud size distribution of R. cantleyi is dynamic, progressively changing from small flower buds to larger buds before flowering. Buds < 5.0 cm across had the slowest growth and highest mortality rates, while those > 15.0 cm across demonstrated accelerated growth. The bud growth profiles of the same site clustered distinctively regardless of sex with successful blooming rate that varied greatly between sites, prompting speculation about their relatedness to the sites’ physical attributes. We reported the first female-dominated population in Rafflesia’s life history. Rafflesia cantleyi’s blooming rate at Lata Jarum is moderate to high, with non-seasonal flowering phenology as evident by the lack of synchronisation and consistency between flowering and local rainfall patterns. Based on the field data of the present study and the published information of other Rafflesia species, R. cantleyi’s life cycle was estimated between 4.0 and 5.3 years. Our findings further explain Rafflesia’s biology and life history and highlight the gap in knowledge of the natural habitats on the endoparasite’s growth and fate potentially for future conservation and study.
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... The most extreme cases of dust seeds though, come from Rafflesia and Hydnora, whose large fleshy fruits contain tens of thousands of minute seeds. Given the odds of successful reproduction in these two genera-distantly located dioecious flowers, highly skewed sex ratio, animal-vectored pollination and seed dispersal, and host-stimulated germination-high fecundity is a necessity (Bolin et al., 2009b;Pelser et al., 2013). ...
Rethinking convergence in plant parasitism through the lens of molecular and population genetic processes
Article
  • May 2023
  • AM J BOT
The autotrophic lifestyle of photosynthetic plants has profoundly shaped their body plan, physiology, and gene repertoire. Shifts to parasitism and heterotrophy have evolved at least 12 times in more than 4000 species, and this transition has consequently left major evolutionary footprints among these parasitic lineages. Features that are otherwise rare at the molecular level and beyond have evolved repetitively, including reduced vegetative bodies, carrion-mimicking during reproduction, and the incorporation of alien genetic material. Here, I propose an integrated conceptual model, referred to as the funnel model, to define the general evolutionary trajectory of parasitic plants and provide a mechanistic explanation for their convergent evolution. This model connects our empirical understanding of gene regulatory networks in flowering plants with classical theories of molecular and population genetics. It emphasizes that the cascading effects brought about by the loss of photosynthesis may be a major force constraining the physiological capacity of parasitic plants and shaping their genomic landscapes. Here I review recent studies on the anatomy, physiology, and genetics of parasitic plants that lend support to this photosynthesis-centered funnel model. Focusing on nonphotosynthetic holoparasites, I elucidate how they may inevitably reach an evolutionary terminal status (i.e., extinction) and highlight the utility of a general, explicitly described and falsifiable model for future studies of parasitic plants.
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... This is perhaps a direct consequence of the little that we know of its biology, especially of its seeds. Small mammals, like shrews previously observed to gnaw on the hard covering of the fruits, are believed to facilitate seed dispersal (Bänziger, 2004;Nais, 2001), though ants have also been seen transporting the seeds (Pelser et al., 2013(Pelser et al., , 2016. How these seeds germinate and infect the host is unknown (Wicaksono et al., 2021), but after the seed germinates in the host, it seems that the Rafflesia endophyte can persist in the vegetative stage for years (M. ...
The seed transcriptome of Rafflesia reveals horizontal gene transfer and convergent evolution: Implications for conserving the world's largest flower
Article
Full-text available
  • Apr 2023
Societal Impact Statement Rafflesia is a genus of parasitic plants with the largest flowers in the world, unique to the threatened forest habitats of tropical Asia. Here, we report on genes that are active (the transcriptome) in Rafflesia seeds as part of a larger effort to understand Rafflesia. Rafflesia has never been grown successfully outside of its native range. Consequently, seed banking is not yet possible, precluding a critical management strategy for conservation. The study of Rafflesia seed biology is a critical step to improve its cultivation, which will educate the public about unique species and the importance of conserving their habitats. Summary Rafflesia is of great interest as one of the only two plants known to have completely lost its chloroplast genome. Rafflesia is a holoparasite and an endophyte that lives inside the tissues of its host, a tropical grape vine (Tetrastigma), emerging only to bloom—with the largest flower of any plant. Here, we report the first Rafflesia seed transcriptome and compare it with those of other plants to deepen our understanding of its extraordinary life history. We assembled a transcriptome from RNA extracted from seeds of the Philippine endemic Rafflesia speciosa and compared this with those of other plants, including Arabidopsis, parasitic plants Striga and Cuscuta, and the mycoheterotrophic orchid Anoectochilus. Genetic and metabolic seed pathways in Rafflesia were generally similar to the other plant species. However, there were some notable exceptions. We found evidence of horizontal transfer of a gene potentially involved in circumventing host defenses. Moreover, we identified a possible convergence among parasitic plants because Rafflesia, Striga, and Cuscuta shared important similarities. We were unable to find evidence of genes involved in mycorrhizal symbiosis, suggesting that mycoheterotrophy is unlikely to play a role in Rafflesia parasitism. To date, ex situ propagation of Rafflesia by seed has been mostly unsuccessful. Our research is a bold step forward in understanding the fundamentals of Rafflesia seed biology that will inform the continued propagation and seed‐banking efforts concerning this recalcitrant plant. We discuss our findings in the broader context of the conservation of a genus in peril.
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Rafflesia panchoana (Rafflesiaceae), a New Species from Luzon Island, Philippines
Article
Full-text available
  • Dec 2007
A new species, Rafflesia panchoana Madulid, Buot & Agoo, is de- scribed from Mt. Makiling, Luzon Island, Philippines. It is similar in size to R. manillana Teschem. but differs in having an upright or slightly inclined dia- phragm, smaller warts on the perigone lobes, elongated or stretched windows on the underside of the diaphragm, and bristles on the rim of the annulus.
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Rafflesiaceae
Article
  • Jan 1997
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The developmental anatomy of Conopholis americana (Orobancaceae) seedlings and tubercles
Article
  • Jan 2011
  • CAN J BOT
Germinated and attached seedlings of the phanerogamic parasite Conopholis americana (L.) Wallroth are described for the first time. The morphogenetic changes which characterize the transition from seedling to preflowering tubercle, as well as the anatomy of the mature tubercle, including endogenous floral buds, are also described. Conopholis seedlings were found attached only to mycorrhizal oak roots. The primary haustorium attached to and penetrated the fungal sheath, pushing aside epidermal and cortical cells of the host as it grew toward the host stele. Cells of the endophyte contacted host xylem and differentiated directly into reticulately thickened tracheary elements. Concomitantly a cambial are of parasite origin was established within the young tubercle, aligned with the vascular cambium of the host root. The cambium of the tubercle gave rise to xylem centripetally, which differentiated into tracheary elements juxtaposed to host secondary vessels, and cortical parenchyma centrifugally. Sieve elements could not be unequivocally demonstrated in seedlings or tubercles. Tissues and cell types of the parasite could be distinguished from those of the host by both morphological and histochemical criteria. The parasite to host transition zone was characterized by direct tracheary element connections and delimited by densely cytoplasmic parasite parenchyma cells that had greatly enlarged centrally located nuclei.
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