A second new species of Rafflesia (Rafflesiaceae) from Panay Island, Philippines

A second new species of Rafflesia (Rafflesiaceae) from Panay Island, Philippines

Renee Galang* and Domingo A. Madulid**


*Philippine Spotted Deer Conservation Foundation, Victoria, Australia
**Botany Division, Philippine National Museum, Manila, Philippines


Summary
Rafflesia lobata Galang & Madulid, is a new species from Panay Island, Philippines. It has small flowers similar to R. manillana but differs in having a lobed usually outcurved diaphragm which is almost white when fully opened. Diaphragm forms range from the more common five shallow lobes to uncommon 3 incurved lobes.

Key words
Rafflesia, Rafflesia lobata, Panay, Philippines

Introduction
In April 2005 the first author made an expedition to Mt. Igtuog and Mt. Sakpaw in the northern section of the Central Panay Mountain Ranges in connection with his fieldwork observation of the Spotted Deer (Cervus alfredi). In the course of his exploration of the lowland primary forest he encountered a population of Rafflesia in Mt. Igtuog which composed of several plants of various ages and sizes. No newly opened flowers were seen but the plants were already black and had passed their blooming period while some buds appeared to be diseased. No collection of Rafflesia specimen was made during the visit.

In a follow up visit in September, 2005 another population of Rafflesia was encountered in Mt. Sakpaw, approximately 10 km away from Mt. Igtuog by the first author. In the site, 11 buds of various sizes and ages were counted. Eighteen flowers were seen, 4 males, 1 female and 13 of unknown gender. All of the flowers were black and partly decomposed. The Mt. Igtuog population was composed of 72 buds of which 4 appeared diseased. Ten flowers were seen: 6 males and 4 unknown gender. Eight of the flowers were black and partly decomposed, but two were of late bloom. Three mature fruits were seen and one was ripe. Initial studies were made on the biology and distribution of the species and will be reported in a separate account. Collection of specimens were made after securing a Gratuitous Permit by the first author from the Department of Environment and Natural Resources office in Region VI on June 21, 2006.

This species is the second to be recorded in the island of Panay, the first being R. speciosa Barcelona & Fernando reported in the southern section of the Central Panay Mountain Ranges in Antique and Iloilo.

Rafflesia lobata Galang & Madulid, sp. nov.

A R. manillanae differt diaphragmate extrorsus curvato, perfecte
aperto fere albo, lobis non profundis plerumque quinque vel raro
quattuor, vel tribus in diaphragmate parum incurvato, manifestis etiam
longe ante anthesin; ramentis brevibus albis, aliquibus extensis ad
bases loborum perigonii; habitat praeterea in insula Panay, non (ut
R. manillana) in Luzonia.

From R. manillana it differs in a diaphragm curved outwardly, fully open nearly white, with usually five or rarely four shallow lobes, or three [lobes] on a slightly incurved diaphragm, evident even long before anthesis; ramenta short, white, some extending to the bases of the lobes of the perigone; it dwells, moreover, on Panay island, not (as R. manillana) in Luzon.

Type: Philippines, Panay Island, Antique Prov., Sebaste Municipality, Barangay Idio, Mt. Igtuog. June 24, 2006 (holotypus Galang et al. 001 PNH, spirit collection).

Mature buds 61-65 mm in diameter. Flowers 11-21 cm diameter, 6-9 cm high when expanded. Perigone lobes orbicular to oblong, 4 -5 cm x 6-7 cm, 0.05 cm thick at tip, gradually thickening to 0.625 cm at junction with diaphragm, brown, becoming darker brown with age then black; warts wet snow white, oval to oblong-shaped, 1 mm x 3 mm, slightly raised, to 0.09 cm, occasionally with raised linear warts across the length. Perigone tube covered with variously-shaped, short ramenta. Diaphragm usually outcurved with 5 or 4 lobes, or with 3 lobes which are incurved, diaphragm opening to 4.5 cm, lobes 1 x 3.5 cm, half moon or crescent-shaped, the lower part adnate to the perigone tube, with roundish depressions underneath, surface covered with numerous, small, creamy white warts or windows. Disk dome-shaped, to 3.3 cm diameter; column 1.5 cm above the base of the perigone tube; processes 7-14, elongate, to 0.3 cm tall on central disk and 0.4 cm towards the rim of central disk, processes to 0.1 cm thick and 0.2 cm wide, top of processes with numerous fine bristles; perimeter of disk with numerous small convex bumps with numerous fine bristles 0.1 cm long, annulus diameter to ca. 5 cm, interior covered by thick, black, spear shaped bristles, to 0.01 cm long. Ramenta to 0.05 cm diam. x 0.1 cm high, numerous on perigone tube extending to the inner side of diaphragm, lower ramenta columnar with funnel shaped, multi-lobed top to 0.2 cm high 0.125 cm diam. Middle to upper ramenta pustulate, to 0.1 cm high with 0.025 cm, multi-lobed crown. Numerous radial ridges radiating from the annulus exterior to the inner half of diaphragm. Male flowers with 10-11 anthers; anthers brown, 0.53 cm diameter, anther cavity on underside of disk 1 cm wide with densely fine bristles; anther cavity between the base of the column and annulus interior is 1.2 cm x 0.75 cm radial, each anther cavity has rims and radiating ridges on the center lined with thick 0.01 cm long bristles. Female flowers with ovary to 4 cm wide at apex, 1.0 cm high, annulus indistinct, and without grooves or cavities, lower side of disk with few minute, scattered papillae on the stigmatic zone.

Note: The first author saw the fruits in the field but it was not possible to preserve them at the time. However, based on those observations the fruit was 57-65 mm diameter , black, with slightly rough outer cover; with creamy white flesh, slightly pungent. Seeds were orange, approximately 123,600, oval shaped, 0.05 cm x 0.025 cm, on edge of vertical columned placenta.

Local name: not known
Distribution and ecology: Philippines, Panay Island, northern section of the Central Panay Mountain Ranges. On the western slope of Mt. Sakpaw and eastern slope of Mt. Igtuog , Barangay Idio, Municipality of Sebaste, Province of Antique. In April to June 2006, a site in Barangay Maadios and 4 sites in Barangay Idiacacan, Municipality of Pandan, Province of Antique were observed and verified by the first author to have small populations with fresh blooms. Elevation ca. 400-800 m above sea level, mostly in gullies, on forest floor or attached to vines in primary lowland rainforest. The species occasionally produces one or few flowers all year round. From February to June appear to be the optimal flowering period due to numerous flowers observed in 2006.

Only host plant observed is Tetrastigma tuberculatum ( Vitaceae), a woody vine. Most of the healthy buds of R. lobata are attached to the lower part of the vine where it touches the ground although some buds can be found attached to the stems as high as 15 meters above the ground.
Specimens Examined: Philippines: Galang, R. et al. 001, and 002, Mt. Igtuog, Barangay Idio, Municipality of Sebaste, Province of Antique, June 24, 2006; Galang, R. et al. 003 and 004, Mt. Igtuog, Barangay Idio, Municipality of Sebaste, Province of Antique June 26, 2006; Galang, R. et. al. 005 and 006 Mt. Sakpaw, Barangay Idiacacan, Municipality of Pandan June 28, 2006. Specimens are deposited at the Philippine National Museum. All flowers are in spirit collection.

Notes: Rafflesia lobata is similar to R.. manillana: in flower diameter size which ranges from 11 to 21 cm for the former and 15 to 20 cm for the later; in perigone lobe colour both species are of brown to light reddish brown; and both species ramenta are similar in structure and length. The differences are: in diaphragm, R. lobata has white colour on the outside and is lobate. Most flowers have 5 shallow out-curved lobes; flowers with 4 shallow out-curved lobes were also observed but rare. Three-lobed flowers were also rare but interestingly have slightly incurved diaphragm. R. manillana has brown and classical incurved diaphragm like all Rafflesia species. The presence of this lobate diaphragm which is out-curved in most flowers observed in all 7 currently known different populations strongly suggest that it is highly unlikely that these populations are a rare mutant form of R. manillana. Preliminary parsimony analyses by Todd Barkman based on ITS sequence data suggests that R. lobata is distinct from R. manillana and R. speciosa but forms a clade with them.

The presence of lobate diaphragm which is generally outcurved on this new species means that the description of the genus Rafflesia requires an amendment to include species with an outcurved lobed diaphragm, like R. lobata, not just species with incurved diaphragm.

Acknowledgements
We wish to thank the field guides of the Philippine Spotted Deer Conservation Foundation, Rene Ebon, Lucreto Tenorio and Herbert Magluyan and its 2005 volunteers Darren Jones, Peter Fragapoulus, Sharmaine G. Casaol, Janelle McKenzie and Melanie Bondin who conducted field study in Mt. Igtuog and Mt. Sakpaw. We also thank the following government officials: DENR Region VI Regional Executive Director Julian D. Amador, Arlene T. Dalawis, OIC, RTD, and Chairperson, Regional Wildlfe Management Committee, for granting Wildlife Gratuitous Permit to collect specimens in the mountains of Panay ; Culasi, Antique especially Damaso Fuentes and Amadona Rana, Pandan Mayor Plaridel E. Sanchez VI, Sebaste Mayor Jose Christopher A. Varona , Barangay Captain of Idiacacan Gil V. Ambubuyog, Barangay Captain of Idio Isabelo P. Bulos and Kagawad of Idio Gatong Sejera for their support and cooperation:. Todd Barkman, Department of Biological Sciences, Western Michigan University continually supported the authors during the process of the description. We acknowledge the valuable help of Abdul Latiff and M. Wong for reviewing the manuscript. Illustration of the specimen was made by Abner de Guzman, Botany Division, National Museum. We wish to thank Director Corazon S. Alvina for her support to this project.

References
Barcelona, J. and E. Fernando. 2002. A new species of Rafflesia (Rafflesiaceae) from
Panay Island, Philippines. Kew Bulletin 57(3):647-651.
Meijer, W. 1997. Rafflesiaceae. In: Flora Malesiana, Series I, Vol. 13, 1-42.
Nais, J. 2001. Rafflesia of the World. Sabah Parks, Kota Kinabalu, Malaysia

h*tp://www.rafflesialobata.org/2ndspecies.html