AMORPHOPHALLUS FLAMMEUS
PROTOLOGUE: Amorphophallus flammeus Calaramo, Batuyong, Bulawin & Alejandro, published in Nordic Journal of Botany 2022(6)-e03491: 6 (2022).
A species appearing to be intermediate between Amorphophallus paeoniifolius and Amorphophallus urceolatus, but with a very distinct deeply undulate/plicate spathe limb. Furthermore, it has a shallow spathe base without constriction between the spathe base and limb (versus urceolate spathe base with slight to pronounced constriction before the spathe limb in Amorphophallus urceolatus, Drawing 1), wide-opening spathe lamina exposing the male and female zone (versus a constricted opening in Amorphophallus urceolatus which slightly hides the male and female zone in side view), and a long style and dense ovary (versus short style ‘as long as the ovary’ in Amorphophallus urceolatus; Hetterscheid et al. 2020, plate no. 4).
Type: Philippines, Ilocos Norte, Municipality of Pasuquin, 8 Jun 2013 (holotype PNH, Calaramo 21300; isotype HNUL Calaramo 21301).
DISTRIBUTION: Philippines: Philippines.
DISTRIBUTION NOTE: Collected in the municipalities of Burgos, Vintar, Pasuquin, Banna, Pinili, Ilocos Norte.
SPECIES DESCRIPTION:
Deciduous herb, up to 80 cm tall. Tuber with thickened top portion where the buds develop a series of bracts, enclosing the emerging leaves or the inflorescence; irregular in shape, 10–15 × 10–12 cm, with protuberances because of aborted and dried roots when in state of dormancy; lower portion with irregularly globose lumps of massive roots; lesser roots creamy white or yellowish white, their lower end irregularly shaped with signs of geostrophic growth; with developing small plantlets or offsets at the side, these 1–2 cm in diameter, growing outward from the main tuber. Roots observed to be highly associated with some fungi, usually developed on the upper half of the tuber and the base of the leaf petiole, up to 15 cm long and 3.5 mm thick, whitish, with very few root hairs.
Leaf solitary, 70–80 cm across, but sometimes a smaller stunted leaf emerges beside the dominant leaf. Stipules 2–3, sheathing, enclosing the leaf bud, overlapping in succession before the emergence of the leaf bud; basal stipule subterranean. Petiole 50–100 cm long and 1–4 cm in diameter, spotted greyish green, with fine spots of black or brown pigment at base and larger dark and white elliptical spots towards the rachis. Rachises triply-pinnate to quadri-pinnate, equally divided into two symmetrical rachises, with central rachis positioned in between, terete, light green to green, smooth, winged between leaflets, green, 1–1.5 cm wide; wings unequal, one expanding along the rachilla with the opposite side developing as a leaflet.
Leaflets alternate, becoming subopposite towards the apex, elliptic to elongate-elliptic, uniformly spaced, 5–10 cm long, 2.5–4.0 cm across; leaflet lamina normally oblique at base, narrowly acute to acuminate at apex, flattened to slightly recurved at apex; margin finely undulate, or very shallowly crenate; adaxial side glossy green; abaxial surface pale or light green; midvein sunken on adaxial side, raised abaxially, 2–3 mm thick, with nervations radiating from the midvein at 45 degrees, 3 mm apart, and terminating with the intramarginal nerve.
INFLORESCENCE:
Flower bud emerging from the top of the tuber, covered by overlapping bracts, 3–4 mm thick, light brown to whitish, followed by two more slender and thinner bracts, exposed above ground, 2–3 cm wide and 1–2 mm thick, lighter in color; peduncle short; immature spathe with a swollen base with slender wrinkled apex.
Inflorescence erect, malodorous like decaying flesh of dead animals in late afternoon at full opening. Peduncle whitish to creamy as the floral bracts dehisce, subterranean, 10–15 cm long, ca. 2 cm long. Spathe broad ovate when flattened, 20–25 cm in vertical length from base to apex, 15–20 cm sideways from margin to margin, at base thickened, convolute, overlapping the basal margin, forming a shallow cup-shaped floral base, outer side spotted light brown to reddish or with greenish margins, inner surface dark blood red, densely verrucose at base with epidermal excrescence, becoming smooth and light towards the limb, exposing the staminate and pistillate floral parts without constriction on floral chamber; limb immediately forming an elaborate well-pronounced lamina, fiery red, spreading and recurved outward; margin very dark, deeply undulate, repeatedly wrinkled and involute; outer side of limb with distinct vertical nerves, greenish, emerging from the central part of the limb to the apex.
Spadix erect, attached to the spathe base, 10–16 cm long, fertile and non-fertile parts differentiated, lacking a non-fertile zone between the male and female parts. Female zone basal, vertical, cylindrical, ca. 3 cm long, ca. 3 cm thick; ovary slightly depressed, 3.5 mm long, 4 mm thick, broad at base, unilocular, dark at the base turning maroon at the apex; placentation basal; style recurved upward, 3–4 mm, dark red, short-conical, broad at base, tapered towards apex; stigma attached to the style apex, fixed, 1–2 mm in diameter, 2- or 3-lobed, transversely bilabiate to a shallow stellate structure with conical lobes, golden yellow turning chocolate brown after stigmatic activity in 2 days, somewhat velvety in appearance; ovary slightly depressed, 2.5 mm long, 4 mm thick, unilocular, dark brown.
Male zone subcylindrical, vertical, ca. 3 cm high and ca. 2 cm in diameter; stamens congested, densely attached to the spadix, truncate at apex, ca. 3.5 mm long, ca. 2.5 mm in diameter; thecae and the connective creamy whitish; male anthesis active after 2 days of flower full opening and then emitting a foul odor like carrion. Pollen golden yellow, erupting in strands.
Appendix thick lanceolate, upright with sometimes recurved round apex, purplish with velvety-like surface, 10–15 cm long, 4–6 cm where widest, with the lower portion slightly wrinkled but becoming smooth entirely up to the distal end.
Infructescence with peduncle elongating to 15–22 cm; spathe scar persistent, with the stamens and appendix abscising; berries yellow to orange at maturity; style turning black, persistent to the fruit apex, orbicular to widely ovate at base, truncate to flat at apex, ca. 4–6 mm long, ca. 3.5–5.5 mm diameter, glabrous. Seeds ca. 5 mm long, ca. 4 mm in diameter, starchy, creamy white.
Amorphophallus flammeus has been observed flowering in March–April, and fruiting in late April–May.
ECOLOGY:
Amorphophallus flammeus was collected in thickets of forest over limestone at an elevation from 300 to 500 m a.s.l.
DISTRIBUTION MAPS:
ETYMOLOGY:
From Latin flammeus, “flaming,” “fiery,” or “fiery red,” referring to the vivid red, strongly undulate spathe limb, which resembles a flame when the inflorescence opens.
NOTES:
1. Apart from the obvious similarity to Amorphophallus urceolatus, by its spathe base Amorphophallus flammeus also has a very close resemblance to Amorphophallus yaoi, but the spadix is distinctively narrow and elongated (Hetterscheid et al. 2020, plate no. 5). Both Amorphophallus urceolatus and Amorphophallus yaoi have incurved spathe limbs, and margins distinctively rolled inward (involute). In contrast, Amorphophallus flammeus is distinct by its strongly plicate margin with fiery red spathe limb, that radiates above ground like a flame when it opens, hence its epithet ‘flammeus’.
Furthermore, by its spathe limb form, Amorphophallus flammeus also has a very close resemblance to Amorphophallus paeoniifolius, but it is entirely different in its spadix. It has been suspected to be a hybrid between Amorphophallus paeoniifolius and Amorphophallus urceolatus, but Amorphophallus flammeus was found in high-elevation limestone thickets, far from the lowland population of Amorphophallus paeoniifolius. Furthermore, the leaf stalk is diagnostically verrucate or warty in Amorphophallus paeoniifolius.
By comparison, the spathe base, limb, spadix and female parts of the published technical description and photograph of Amorphophallus urceolatus are distinctively different from the here proposed Amorphophallus flammeus. Not to fail to mention their distribution and provenance where the latter is restricted to the northern tip of Luzon in the Ilocos Region, whereas Amorphophallus urceolatus is found far south of Luzon (Type Mt Palpag, Maragondon Cavite, M. Medecilo 2015).
Amorphophallus flammeus also closely resembles the African species Amorphophallus mossambicensis (Schott ex Garcke) N. E. Br. Its spathe limb also has pronounced undulate margins, but it is distinguished by a constriction between the base and the spathe limb. Moreover, Amorphophallus mossambicensis occurs only in central Tanzania to southern Tropical Africa.
Amorphophallus flammeus resembles Amorphophallus urceolatus in the spadix and appendix characters, but is distinguished by the spathe base that is not urceolate and lacks a constriction. The spathe likewise does not cover the male and female zone but spreads down to the level of the ovaries. The style is also longer.
Both also closely resemble Amorphophallus yaoi A. Galloway, Hett. & Medecilo. However, Amorphophallus yaoi tends to have a very slender, smooth and very long spadix. Moreover, the spathe margin of Amorphophallus yaoi is not as wavy as that of Amorphophallus flammeus. A comparison between these three species is presented in Table 1.
2. Based on in situ observations, following the IUCN Standards and Petitions Committee (2019), we herein propose Amorphophallus flammeus to be treated as Vulnerable VU B2 a,b (iii). The plant has only been observed in certain locations of the forest. Moreover, unpredictable localized habitat degradation would pose a potential threat to this species.
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus flammeus Calaramo, Batuyong, Bulawin & Alejandro
2. Nordic Journal of Botany 2022(6)-e03491: 6 (2022) — protologue.
Additional photos by Ethan Manzano, Jericho Mendoza, Northwestern University Ecological Park and Botanic Gardens, and Tropical Flora