AMORPHOPHALLUS LONGICOMUS

PROTOLOGUE: Amorphophallus longicomus Hett. & Serebryanyi, published in Blumea 46: 262 (2001).

Amorphophallus longicomus Hett. & Serebryanyi, spec. nov. Amorphophallo piloso similis, tubere depresse globoso, folioli marginibus purpureo-rubris, petiolo glabro, sine staminodiis inter partes masculas et femineas differt. — Typus: Hetterscheid H.AM. 177-T (holo L, spirit coll.), Vietnam, Gia Lai prov., Mang Yang distr., 20 km NW of Can Ha Na, forestry station nr. 2 (coll. from a plant cultivated in the Leiden Botanical Garden; orig. coll.: Cherevchenko & Bogatyr s.n., 1 March 1991, living tuber).

DISTRIBUTION: Vietnam: Vietnam.

DISTRIBUTION NOTE: Vietnam: Gia Lai Province, Mang Yang District (only known from the type locality)².

SPECIES DESCRIPTION:

Tuber globose, no offset development, 7 cm diam., 7 cm high. Petiole 95 cm long, 1.3 cm diam., background dark olive green with numerous scattered, small, slightly raised, blackish dots and scattered, large, whitish greenish spots, these partly confluent and with slightly raised, white, verrucate margins; lamina to 100 cm diam., rachises narrowly or broadly winged distal from the basal main branchings; leaflets elliptic to elliptic-lanceolate, acuminate, 8-15 cm long, 3-4.5 cm diam., upper surface rich deep velvety green with a narrow, lilac purple undulate margin.²

INFLORESCENCE:

Inflorescence solitary, long peduncled; peduncle solitary, 120 cm long, 1.8 cm diam., as petiole; spathe erect, 36 cm long, 28 cm diam., elongate triangular, base and limb separated by a strong constriction, top acute, base outside greyish green with scattered, indistinct whitish orbicular spots and scattered dark green dots, these slightly raised, veins brownish, inside lower 1/3 to 2/3 parts bright greenish yellow, rest maroon with scattered whitish orbicular spots, limb lower part somewhat auriculate, upper part pressed against the appendix, margin slightly undulate, top slightly twisted, outside with a strongly raised midrib, greyish green with scattered whitish orbicular spots, the upper margins flushed pale purple, inside pale maroon with numerous whitish orbicular spots, margins greenish, base within densely covered by short, flaky warts, often forming short transverse ridges. Spadix sessile, much longer than spathe, 66 cm long; female zone cylindric, 3.5 cm long, 2.5 cm diam. (incl. styles), flowers slightly distant; male zone elongate obconical, 5.5 cm long, 2 cm diam. at the top, flowers congested and with scattered hairlike staminodes in between; sterile zone between male and female zone 0.5 cm long, carrying a few scattered hairlike staminodes; appendix elongate conical, c. 57 cm long, 2.5 cm diam. just above the base, base slightly constricted, top acute, wall very thin, rest hollow, surface bright yellow, upper part with a faint purplish flush, entirely densely covered with long, hairlike staminodes. Ovaries depressed, 2.5 mm diam., 1.5 mm high, purple, bilocular; style slender, 5 mm long, 1 mm diam., purple; stigma elliptic in outline, deeply bilobed, 2.5 mm diam. (long axis), 1.5 mm high, lobes conical, subacute or obtuse, surface densely scabrate, dirty yellow. Male flowers consisting of 4-6 stamens; stamens 2 mm long; filaments 0.8 mm long, connate at the base, yellowish; anthers 1.2 mm long, 1 mm diam., orange-yellow; pores apical, elongate, connective broad; pollen orange, psilate.²

ETYMOLOGY:

The species epithet refers to the long, hairlike staminodes on various parts of the spadix.²

NOTES:

1. Amorphophallus longicomus is a member of the Amorphophallus hirtus alliance (Engler's section Dysamorphophallus). The long, densely hairy appendix allies this species morphologically to Amorphophallus hirtus from Taiwan, but it differs primarily from that species in having much longer styles, free filaments and a tuber not producing offsets. Inflorescences similar to that of Amorphophallus longicomus are found in Amorphophallus pilosus (northern Vietnam) and Amorphophallus laoticus (Laos). Both, however, have elongate tubers. Additionally, Amorphophallus pilosus has a short style (1 mm) and an entirely velvety petiole; Amorphophallus laoticus has sessile anthers.²

REFERENCES:

1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus longicomus Hett. & Serebryanyi

2. Blumea 46: 262 (2001) — protologue.

Additional photo by Hoang Truong