|The Cycad Pages
- Cycas rumphii Miq., Bull. Sci. Phys. Nat. Néerl. 2: 45 (1839).
- "TYPE: the illustration: Rumphius 1749: t. 23. (lecto, fide Hill)."
Honouring German-born Dutch naturalist Rumphius (Georg Eberhard
Rumpf, 1628-1702), military officer with the Dutch East India
Company in Ambon, 1652-1657, then with the civil merchant service
of the Dutch East India Company.
Backer & Bakhuizen van den Brink 1963,
Schuster 1932, Kanehira 1938,Peekel 1984, Hill 1994.
Although first legitimately described in 1839 by Dutch botanist
Miquel, the existence of a distinct Malesian
taxon was first recognised by Roxburgh
on the basis
of plants in cultivation in the Calcutta Botanic Gardens. He recognised
that two taxa were present, treating one as C. circinalis
and describing the other as a new species C. spherica.
Roxburgh had, however, mistakenly applied the new name C. spherica
to plants belonging to the C. circinalis group. The distinct Malesian
taxon he then treated under the name C. circinalis, although
he had also mixed material of the two taxa under each description.
This species as recognised by Miquel (1839:
45) was based on part of Olus Calappoides of Rumphius
Miquel was never clear on the specific limits of this taxon, at
first separating material from Sulawesi as C. celebica
(1839: 45), and later
combining the two. He also separated
material from Timor as C. rumphii var. timorensis
(1841: 125), and from Java as C. circinalis var. javana
(1842: 28). In addition, he at first recognised Roxburgh's C.
apparently on the basis of Roxburgh's
published account and without realising the confusion with C.
circinalis. He later
correctly noted Roxburgh's
confusion, and placed C. spherica in the synonymy of C.
circinalis, although later still (1868: 230), he again recognised
C. spherica at specific rank. At the same time (1868: 232),
he placed C. celebica and C. circinalis var. javana
in C. rumphii, with no mention of C. rumphii var.
Recognition of C. rumphii as a distinct species has been
widely argued, with early discussion very ably summarised by Stapf
(1916). Schuster (1932: 74) provided an essentially correct treatment
of this species (with the exception of the varieties and subspecies,
and the New Caledonian material cited), in contrast to his confused
treatment of most other species. The name has been generally accepted
subsequently, although misapplications of the name C. circinalis
to this and related taxa continue (eg.
Warburg also recognised the presence of a coastal taxon in New
Guinea, assigning it to C. rumphii. This coastal taxon
in New Guinea has also been assigned to C. circinalis
Distinguished within the group of species with spongy encocarp
by the broad, falcate, hard, glossy leaflets with
relatively broad bases, present but discontinuous laminar hypodermis,
the relatively long and usually wholly spinescent petiole, and
the narrowly triangular megasporophyll lamina with a slender apical
spine (10-23 mm long) and vestigial lateral spines. Adaxial mesophyll
is usually continuous across the moderately broad and rounded
midrib, but sometimes interrupted by the midrib in the east of
the range. This may be due to genetic admixture of C. bougainvilleana
from further to the east. The condition of reduced lateral spines
also occurs in related taxa from Philippines,
Malaysia and the Indian Ocean. These taxa
are, however, distinguished as a group by the lack of the apical
wing on the seed.
Rumphius in one of the type illustrations showed (somewhat stylistically)
rather distinct lateral teeth on the megasporophyll that do not
accord with other collections from the type region, and more match
C. scratchleyana, also known from the Moluccan region (see above).
For this reason, the other Rumphius illustration hes been selected as
Distribution and habitat:
Cycas rumphii has been poorly understood in the past. Recent
recognition of a number of related species has allowed clarification
of its identity, and clear delineation of its distribution. As now
understood, C. rumphii has a distribution centred on the
Moluccan island group (Maluku, or the Spice Islands) extending east
into Indonesian Papua and a short way along the north coast of Papua New
Guinea, and north to Sulawesi. In the west, it appears to extend to
southern Bornea and north-eastern Java.
C. rumphii appears to share the ecological preferences
of several other taxa in this group, being largely a species of
closed woodland or forest on more or less calcareous substrates
in near-shore environments.
This species is relatively common in cultivation in Fiji and,
to a lesser extent, Vanuatu. In both cases, female plants only
are known, all of which have been vegetatively propagated from
stem offsets. The cultivated plants in both countries show distinctively
yellow new growth that is not typical of the species, which suggests
that they are all of the one clone (see Hill 1994c). These plants
are apparently not interfertile with the native cycad in the region
(C. seemannii), as evidenced by the lack of seed-set in
plants growing with fertile male and female plants of C. seemannii.
Their close relationship would suggest that they are unlikely
to be truly genetically incompatible, and further study is required
to evaluate possible reasons for the lack of hybridisation. Temporal
separation is unlikely, both species having been observed to cone
at almost any time of year. Pollen vectors are not known conclusively,
and both wind and insect pollination have been suggested (see
Pellmyr et al. 1991).
The strong odour reported from both
the male and female cones in the C. rumphii group has been
regarded as both an insect attractant
(Pellmyr et al. 1991). A considerable body of evidence
is now available to support the theory that most cycads are insect
(Donaldson et al. 1993);
Norstog and Fawcett 1987),
and slight chemical differences could mean vector attraction to
one species and not the other.
Conservation status: Unknown. The
1997 IUCN Red List of Threatened Plants lists
C. celebica as category R, although very little is known
of this or in fact most occurrences in this region.
Ftoi (Weda language, Halmahera), nufuès
(Biak dialect, Amdoei village, Irian Jaya), sumo (Wapi language,
Stems arborescent, to 3(-10) m tall, 11-20 cm diam. at narrowest point.
Leaves bright green, highly glossy, 150-250 cm long, flat (not keeled) in section (opposing leaflets inserted at 180° on rachis), with 150-200 leaflets, with orange tomentum shedding as leaf expands; rachis consistently terminated by paired leaflets. Petiole 35-60 cm long (20-30% of total leaf), petiole glabrous, spinescent for 80-100% of length. Basal leaflets not gradually reducing to spines, 190 mm long.
Median leaflets simple, strongly discolorous, 220-320 mm long, 12-16 mm wide, inserted at 70-85° to rachis, decurrent for 5-8 mm, narrowed to 4.5-7 mm at base (to 35-50% of maximum width), 15-19 mm apart on rachis; median leaflets section flat; margins slightly recurved; apex acute, not spinescent; midrib flat above, raised below.
Cataphylls narrowly triangular, soft, pilose.
Pollen cones fusiform, yellow to brown (pale); microsporophyll lamina firm, dorsiventrally thickened, apical spine rudimentary, sharply upturned, 2-5 mm long.
Megasporophylls 18-32 cm long, white-tomentose or yellow-tomentose; ovules 6, glabrous; lamina lanceolate, 50-75 mm long, 25-35 mm wide, obscurely dentate, with 12 soft lateral spines 0-1 mm long, 0-2 mm wide, apical spine distinct from lateral spines, 15-25 mm long.
Seeds flattened-ovoid, 45 mm long, 30 mm wide; sarcotesta orange-brown, not pruinose; fibrous layer absent; sclerotesta apically crested. Spongy endocarp present.