The first time I saw these plants was in 2001, and I remember being struck at how different these were from the stands of Amorphophallus paeoniifolius that were growing at the entrance of the forest, in poor and gravelly soils. These bear strikingly glossy leaflets and smooth petioles that were very much unlike the tuberculated ones in A. paeoniifolius. Their ecology is also very different, preferring more shade and growing amongst leaf litter and humus, often on slopes. Years later, a friend intimated to me that some taxonomists were interested in describing these plants as 'Amorphophallus urceolatus' a nomen nudum until the species formal description in 2020.
The habitat is lowland riverine forest in the province of Laguna on Luzon at about sea level. The banks are flanked by rocks and large boulders. Remnants of felled down trees, likely dipterocarps, still remain. I have been seeing these since the early 2000s and judging by the state of the stumps, I reckon that these were cut sometime around the 70s or mid-80s at the most. Some stretches are already rather bare and invaded by the weedy Mikania vines.
In the intervening years since I first observed these plants, I have seen a marked reduction- even total elimination- of the plants in some spots where I used to see them. The often unstable nature of the rocky slopes meant that minor and localized landslides occur during typhoon season which peaks from July to September every year. Furthermore, fallen branches and palm fronds or snapped-off young trees during heavy rains can do more than temporary mechanical damage to the plants: dense crowns of dying leaves can shade the forest floor considerably for at least a few weeks, further adding pressure to more tender geophytes, particularly Amorphophallus. Still, on steeper slopes and where bamboos predominate, pocket populations do flourish. Bamboos do not break off easily during tropical cyclones and it takes a very long time for dead culms to eventually sever completely and fall. Additionally, the criss-crossing of both live and dead culms serves as a filtering barrier for all but the heaviest of fallen branches.
This uncropped photo shows the typical aspect of its preferred habitat: slopes dominated by large rocks with a dense carpeting of leaf litter and minimal herbaceous competition.
Amorphophallus urceolatus favor dappled shade with some bright, filtered light for at least a few hours each day.
A steep incline offered a surprise. This individual is around 2 feet (60 cm) across. Note the steepness of the slope.
About 10 feet (3 m) beyond it is another inflorescence. This one is about to open its spathe, unfortunately damaged perhaps by falling twigs.
Petioles from plants of this area vary considerably in both color and markings. Here is an unusual, predominantly brown petiole with sparse spots. These individuals remind me of A. fuscus petioles:
Another variation belong to those individuals with green petioles decorated by few and small white spots. This is only the second plant of this species that I have seen with such petiole appearance.
And here is what a typical A. urceolatus petiole looks like- green with brownish overlay and ornamented with white ovals of varying sizes and often coalescing to form larger spots. Smudges beneath these spots lend the illusion of shadow.
Above and below: the more predominating the brown pigment, the bolder the white spots appear. Photo above is ruined by the camera strap, which I did not notice until I viewed the photos at home.
I have seen many examples of A. urceolatus from this area, but this is the only one with those narrow leaflets: This plant is about 5 feet (1.5 m) in diameter.
Another large specimen, of a more typical presentation.
Amorphophallus urceolatus occurs in sympatry with bamboos and palms such as Arenga pinnata and Saribus rotundifolius, as well as other aroids such as Rhaphidophora elmeri and Aglaonema commutatum var. maculatum (below).
Amorphophallus rostratus is a much rarer species here than does A. urceolatus. The third species, A. paeoniifolius, is found within settlements and is unable to colonize the forest. Its propensity for more open and brighter spots perhaps explains this inability. Photo of a seedling A. rostratus below:
The polymorphic Begonia nigritarum is usually found growing vertically on rocks.
Orchids are a notable component of the forest here, and among those that exist in propinquity with A. urceolatus are Phalaenopsis equestris, Vanilla sp., Hetaeria oblongifolia, and Pomatocalpa bicolor (respectively, below).
Further exploring yielded a gold mine. Would have been a more spectacular sight if I had come here a few days earlier. This colony appears to consist of at least a few generations of seed batches which tumbled down from the same overhead parent source, though the smaller plants may also be offsets of the larger and more mature individuals.
This should give you an idea of the entire structure's size. These plants typically have larger and darker colored 'flowers' than those from the neighboring province of Rizal, as well as the populations from Cavite and Mt. Makiling, also in the province of Laguna, suggesting a distinct ecotypical variation. For this species' formal description, proceed
here.
Visible on the upper left corner is a vine of Hoya meliflua.
The next three photos show the insides of the three senescing inflorescences. The female zones have been dusted with pollen; since these are wild plants and the structures are in close proximity to one another, it is perhaps safe to assume that cross pollination has occurred on at least one of the inflorescences.
Photo below shows beetles trapped inside the urn of the intact inflorescence, along with some debris from the forest. Blow flies are very seldom seen in this forest.
At about 2:30 PM, the stench is already wafting in the jungle air with the odor of putrefying fish. Observations from plants that I have flowered at home suggest that by about 4 PM, the scent gives way to one of rotting warm-blooded carcass, reaching its peak between 7-8 PM before tapering off noticeably two hours later.
Twenty years of field observations from this area imply that A. urceolatus has a poor dispersing ability, which comes as a puzzle given the diversity of birds here. It is common to see seedlings of the same batch clustered together around a larger plant. Additionally, certain patches seem very suitable for this species and yet, not even a single individual can be found. In comparison, I am yet to find the mature plants of A. rostratus that could have produced the younger plants I have been encountering for the past two years. It would seem that the much taller peduncles of A. rostratus (it is the tallest Philippine species and rivals the height of the Sumatran A. gigas) are much more adept at advertising to potential avian dispersers than do inflorescences that sit on the ground, such as A. urceolatus'. An alternative explanation to A. urceolatus' poor recruiting capability is that the berries are instead dispersed by mammals and that these mammals' numbers are on a decline. In my two decades' worth of trips to this forest, I have encountered only two batches of bushmeat hunters, the first of which (2001) held a freshly captured buot (cloud rat, Phloeomys pallidus), while the second one (2014) was on their way back home, empty-handed. However, the paucity of such encounters does not necessarily reflect a scarceness in both the hunters' presence and their effects on the wildlife, and it may be that the gravity of their depredations may be more significant than I have previously assumed. At this point, I would like to mention that I have more than once observed the presence of another type of hunter- feral dogs- in this forest. Apart from cloud rats, two species of civets occur here- Viverra tangalunga and Paradoxurus hermaphroditus, locally known as 'musang' and 'alimos/alamid', respectively. Both are omnivores, with fruits making up a significant percentage of their diets. I know for a fact that on a nearby sitio (the farthermost reach of a barangay, which in turn is the smallest political unit in the Philippines), men own firearms to shoot down wild fowl, monitor lizards, and civets for consumption. It is not at all improbable to presuppose that they also venture here for the same purpose. Scats were frequently observed on the rocks littering the banks, deposited by mammals possibly sometime during the course of the night as they descend from the trees and banks to take sips from the river below, but such observations have become less and less frequent for the past three years, with the animals likely being driven to the more inaccessible regions of the forest. Nevertheless, for all its grim possibilities, it must also be mentioned that a significant chunk of the habitat is precipitous, densely vegetated slopes which should afford formidable protection to several of its natural denizens, including A. urceolatus.
Berries should be ripe by late October, and unless there will be another round of lockdowns due to the looming threat of the COVID Delta variant, then I shall make a return trip and attempt to disperse seeds on aforementioned suitable spots, thereby increasing the range of the plants while also providing a future source of food for its embattled beasts.
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