AMORPHOPHALLUS LANCEOLATUS
PROTOLOGUE: Amorphophallus lanceolatus (Serebryanyi) Hett. & Claudel, published in Aroideana 35: 43 (2012).
Pseudodracontium lanceolatum Serebryanyi, spec. nov. Planta laete viridis. Pedunculus petiolo longior. Laminae segmentis superioribus angusto lanceolatis, ad 24.5 cm longus, 5 cm latis, apice acuto. Flores masculi distantes. Stigma discoideum, stylum superans. Appendix cerebriformis, pallide flavovirens. — Typus: Hetterscheid H.AM. 179-T (MHA holo; spirit coll.), 15 July 1992, cult. Hort. Bot. Leiden ex Vietnam, Xuen Moc Reserve, easternmost part of Dong Nai Prov. (orig. coll. Kuznetsov, 1991).
SYNONYMS:
HOMOTYPIC SYNONYMS: Pseudodracontium lanceolatum Serebryanyi in Blumea 40: 230 (1995)
DISTRIBUTION: S. Vietnam: Vietnam.
DISTRIBUTION NOTE: Vietnam: Ba Ria - Vung Tau Province, Xuyen Moc (the Xuen Moc Reserve; only known from the type locality). The type came from the same 1991 Kuznetsov collection as the type of Amorphophallus kuznetsovii.³.
SPECIES DESCRIPTION:
Tuber elongate. Petiole to 46 cm long, 1 cm diam. at the base, bright green with numerous, small, scattered white spots and fewer and larger dark green spots in the lower half; anterior main segment three-sect, to 35 cm long; posterior main segments 5-sect, 35-38 cm long; 'leaflets' (narrow-)lanceolate, acute, the largest up to 24.5 × 5 cm, upper surface glossy green, main vein impressed, lower surface paler, main vein whitish and strongly raised.³
INFLORESCENCE:
Inflorescence distinctly taller than the leaf; peduncle to 63 cm long, 0.7 cm diam. at the base, pale yellowish green with a few almost indistinct, pale green spots and a few smaller whitish spots. Spathe strongly fornicate, acute, to 12 cm long, outside green at the base, distinctly paler to the top. Spadix to 7.5 cm long; female zone 0.8 cm long, 0.7 cm diam., flowers congested; male zone 3 cm long, 1.2 cm diam., flowers very distant; appendix almost sessile (not clearly stipitate), narrowly conic, acute at the top, pale yellowish green, equal to the male zone in length, to 1 cm diam. at the base, surface brain-like, rugae branching and interconnecting in all directions. Ovaries depressed-conic, cross section rounded to angulate, c. 2 mm diam., whitish green; style c. 0.5 mm long; stigma distinctly larger than style, slightly hemispheric, surface scabrate, 0.8-1 mm diam. Male flowers consisting of 4-6 stamens; filaments of upper and lower flowers connate, in middle flowers partly connate or free; anthers in upper flowers free or variously connate, in middle flowers mostly free, in lower flowers synandrious. Fruits and seeds not seen.³
ECOLOGY:
Found only solitary under the forest cover³
ETYMOLOGY:
The species epithet refers to the shape of the 'leaflets'.³
NOTES:
1. Pseudodracontium lanceolatum is easily distinguished by the extremely narrow, lanceolate 'leaflets', bright green vegetative parts, the male zone with very distant flowers, a pale yellowish green appendix and the discoid stigmas distinctly larger than the styles.³
2. When molecular and morphological evidence showed the genus Pseudodracontium to be nested within Amorphophallus, Hetterscheid and Claudel transferred the species as Amorphophallus lanceolatus.²
3. Amorphophallus lanceolatus is one of the Vietnamese members of the Amorphophallus lacourii complex, a group of about five species currently being studied with molecular genetic data, inter-population variability, distribution, and habitat patterns.⁴
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus lanceolatus (Serebryanyi) Hett. & Claudel
2. Aroideana 35: 43 (2012) — protologue.
3. A taxonomic revision of Pseudodracontium (Araceae). Blumea 40(1): 217-235 (1995)
Additional photos by Eli Dreyer