AMORPHOPHALLUS FALLAX
PROTOLOGUE: Amorphophallus fallax (Serebryanyi) Hett. & Claudel, published in Aroideana 35: 43 (2012).
Planta viridis, bifoliata, ad 70 cm alta. Pedunculus petiolo paulo longior. Stigma sessile vel subsessile, hemisphericum. Appendix basi papillata, cerebriformis, longitudine fissurata Typus: Serebryanyi 8908 (MHA holo, spirit coll.), Vietnam, Vung Tau-Con Dao Special District, limestone hills c. 10 km E of Vung Tau port, near mount N. Chau Vien, 300 m alt., SE slope, 100 m below the Jesus Christ monument, in thickets, 28 May 1989.
SYNONYMS:
HOMOTYPIC SYNONYMS: Pseudodracontium fallax Serebryanyi in Blumea 40: 221 (1995)
DISTRIBUTION: S. Vietnam: Vietnam.
DISTRIBUTION NOTE: Vietnam, Vungtau-Con Dao special district, limestone hills c. 10 km E of Vung Tau port; near Mount N. Chau Vien, 300 m. alt., SE slope, 100 m. below Jesus Christ momument, in thickets, 28 May 1989.
SPECIES DESCRIPTION:
Plants mostly simultaneously bearing two leaves and two inflorescences or an inflorescence and an infructescence. Tuber strongly elongate, up to 15 cm long, accessory buds down to 3 cm from the top. Petiole 40–55 cm long, surface glossy, ground colour bright pale green with numerous tiny white spots throughout and fewer larger dark green to dark olive spots and stripes in lower half, colour pattern variable in one plant in different years; anterior main segment almost always undivided, 20–24 cm long, 6–7 cm broad, petiolule 1 cm, oblong, apex shortly acuminate, leathery; upper surface usually dull pale green, occasionally glossy dark green in plants of the same population, never variegated; main vein impressed, lower surface dull or moderately glossy green, main vein prominent, inner collective vein 4–6 mm distant from the margin; posterior main segments 28–29 cm long, each with 4 to 7 ‘leaflets’, these 9–13 cm long, 6–7 cm broad, broadly to oblong ovate.
INFLORESCENCE:
Peduncle 47–52 cm long, to 0.9 cm diam. at the base, very turgid; colour as petiole, with slightly more white spots. Spathe cymbiform, slightly fornicate, outside green during female anthesis, slightly paler during male anthesis (usually next day), inside pale green, up to 13 cm long, c. 7 cm diam., 2–3 cm longer than spadix, long acute, base convolute, margins of limb strongly involute, base inside with several warts. Spadix 9–11 cm long; female zone cylindric, 1 × 0.9 cm, enlarging during fruiting stage up to 4 × 2 cm; male zone cylindric, 3.5–4 × 1.3 cm long; appendix stipitate, conic, subacute, brain-like with a few more or less longitudinal deep fissures, the lower part occasionally papillate, ivory white, 3.7–4.2 cm long, 1.3 cm diam., stipe up to 0.5 cm long. Ovaries depressed, prismatic in cross section, c. 2 mm diam., whitish; stigma sessile or on very short indistinct style (c. 0.2–0.5 mm), hemispheric, 0.5 mm high, to 0.8 mm diam., surface strongly scabrate. Male flowers congested, consisting of (3–)4–7 stamens; upper flowers with shortened, irregularly to completely connate filaments; anthers irregularly connate, middle flowers with long, erect, mostly free filaments, occasionally connate with adjacent anthers; lower flowers entirely synandrous with occasionally reduced thecae. Infructescence with the dried lower part of spathe remaining; berry dark orange when mature although green berries may contain viable seeds, nearly quadrangular, c. 0.5 cm long, 3 mm thick; seed white, solitary, oblong-ovoid, laterally compressed, 4 × 2.5 mm.
ECOLOGY:
Amorphophallus fallax is rare on the steep slopes of limestone hills in the vicinity of the Vung Tau port, at 200 m altitude. The vegetation is damaged by fires and cutting and consists of a developing cover of Bambusa inermis (5–7 m high), Bombax sp. (3–4 m high) and grasses. The soil layer is thin, rich, chernozem-like. Amorphophallus fallax flowers from May to June and fruits in June and July. In the type locality also Amorphophallus scaber Serebryanyi & Hett. and Amorphophallus lacourii are found. Tuberous aroids occur in communities with Kaempferia angustifolia Rosc., K. galanga L., K. laotica Gagnep., and Tacca leontopetaloides (L.) Kuntze.
ETYMOLOGY:
From Latin fallax, “deceptive,” “misleading,” or “false,” referring to the deceptively similar appearance of the spadix to that of related species. This resemblance can make the species difficult to identify from the inflorescence alone, particularly when vegetative characters are unavailable.
NOTES:
1. Originally catalogued as Pseudodracontium fallax. In 2012, Hetterscheid and Claudel recombined the genus Pseudodracontium into Amorphophallus (Aroideana 35: P.35)
2. Amorphophallus fallax resembles Amorphophallus lacourii, though differs in the sessile or subsessile stigmas and the more or less longitudinally deep fissured appendix with the lower part occasionally papillate. However, vegetatively Amorphophallus fallax cannot be confused with Amorphophallus lacourii, being entirely green and bearing simultaneously two leaves and two inflorescences or an inflorescence and an infructescence (see also the notes to Amorphophallus lacourii).
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus fallax (Serebryanyi) Hett. & Claudel
2. Aroideana 35: 43 (2012) — protologue.
3. Asian Flora
5. Blumea - Biodiversity Evolution and Biogeography of Plants 40:217-235
Additional photos by Andreas Haberlag, Brad Mayger, Cory Dale, Jeremy Holden, Rene Schieber and David Scherberich