This species was originally collected on the island of Mindanao (Mt.
Apo) in the
Philippines in 1882 (type attributed to either Hieronymus (Meijer,
1997; Nais, 2001) or Schadenberg and Koch (Merrill, 1923).
Despite concerted efforts by field botanists, R. schadenbergiana had not been
seen and was presumed extinct. Previous reports of R. schadenbergiana on Mt. Matutum
(e.g. Nais, 2001)
are erroneous (J. Barcelona, pers. comm.). A bud from Mt.
Matutum examined at the Central Mindanao
University in Bukidnon Province in 2002 represents a small-sized
Rafflesia, too deteriorated
for proper identification.
After 112 years since it was first discovered by the German ethnologist
Schadenberg, R. schadenbergiana,
was rediscovered on the island of Mindanao. In 1994 Pascal Lays found
buds of R. schadenbergiana
in South Cotabato Province on the island of Mindanao. His paper
reporting this result has only recently been published. Moreover, Dr.
Julie Barcelona reports on the discovery of yet another population of
this rare species in Bukidnon (Barcelona et al. 2008).
The morphological features of these flowers fit well
with the original descriptions of this species (see below).
Moreover, this is the largest flower among all the species of Rafflesia present in the
Philippines, ranging from 52 to 70 cm in diameter. For these reasons,
there is little doubt that this taxon is R. schadenbergiana.
The Bukidnon "population" contains several buds, flowers, and
fruits, but all
are apparently parasitic on a single individual of the host vine Tetrastigma.
For this reason, these plants are under extreme threat of
extinction and concerted conservation efforts are required to maintain
them for future generations.
Barcelona, J.F., P.B. Pelser, A.M. Tagtag, R.G. Dahonog & A.P. Lilangan. 2008. The rediscovery of Rafflesia schadenbergiana Göpp. ex Hieron. (Rafflesiaceae). Flora Malesiana Bulletin 14(3):162-165.
Meijer W. 1997. Rafflesiaceae. Pages 1-42 in Kalkman C, Kirkup DW,
Nooteboom HP, Stevens PF, de Wilde WJJO, eds. Flora Malesiana, vol. 13.
Merrill ED. 1923. An Enumeration of Philippine Flowering Plants, Vol. 2
. Loranthaceae pp. 100-112. Manila Bureau of Printing.
Nais J. 2001. Rafflesia of the World. Kota Kinabalu: Sabah Parks.
Julie Barcelona next to an open Rafflesia
schadenbergiana flower and an unopened bud.
The habitat of Rafflesia
schadenbergiana near an agricultural area. Photo by Julie
A fully open Rafflesia
schadenbergiana flower. Photo by Julie Barcelona.
The next generation upon whom the survival of this magnificent species
depends. Photo by Julie Barcelona.
Two photos of the bud discovered in 1994 by Pascal Lays in South
Cotabato Province on the island of Mindanao.
Description translated from the original
German text (Koorders 1918) by Vanessa Ashworth
Warts of the perigone lobes
medium sized, bumpy, often coalescing in a reticulate pattern. Perigone
tube and the interior surface of the diaphragm covered almost to the
margins with filiform ramenta with somewhat club-shaped swollen
endings. A single annulus [coronal ring] protruding diagonally outward;
the outer one represented by a level ring zone that is devoid of
ramenta. Disc similar to previous species [R. hasseltii], as is
the position of anthers in the male flower. Disc edge densely
short-hairy above the anthers, as is the entire column. Anther cavities
very flat, not extending half way down the column width, recessed on
the upper side; ridges between them [the anther cavities] here narrow
and pubescent at the edge. In the female flower the stigmatic ring
forms a weak outer ridge; indented in front of the anther rudiments.
Below each one of these [rudiments] there is a shallow area surrounded
by hairs which is the rudiment of the anther cavity; column otherwise
flat and everywhere short-hairy.
Description From Flora Malesiana treatment (W. Meijer, 1997)
Flower buds prior to expansion 16-20 cm in diameter, cupule 10-14 cm in
diameter, bracts up to 17-18 cm long, 12-13 cm wide. Open flower about
80 cm in diameter. Ramenta on the inside of the flower tube 7-10 mm
long, filiform, somewhat thickened at the apex, or branched, partly in
fascicles. Diaphragm 6-8 cm from insertion to opening, opening 13-14 cm
in diameter, margin with pinkish zone, lower face except the marginal
zone provided with ramenta ca. 4-5 mm long. Perigone lobes 25-26 cm in
diameter, with yellowish whitish warts which are laterally stretched,
irregularly shaped, partly connected and about 4 or 5 [in number]
across the middle part. Disk 12-13 cm in diameter, processes 30-50.
Male flowers with 26-38 (-40) anthers.
Last updated: 27-July-16 / dln