AMORPHOPHALLUS NAPIGER
PROTOLOGUE: Amorphophallus napiger Gagnep., published in Notulae Systematicae (Paris) 9: 119 (1941). The protologue is reproduced below.
DISTRIBUTION: E. Thailand to Vietnam: Cambodia, Laos, Thailand, Vietnam.
DISTRIBUTION NOTE: Thailand: Mukdahan Province - the type was collected at Pu-maro, near Mukdahan (Kerr 21436).².
SPECIES DESCRIPTION:
Translated from protologue: Tuber turnip-shaped, irregular, sinuously constricted, 6 cm long or more, 2.5-3 cm thick at the top. Leaves trisect, the divisions 10-15 cm long, forked at the lowest third, the segments lanceolate, tapering at both ends, in the juvenile state 4-7 cm long and 1-1.5 cm wide, moderately decurrent; the marginal vein 2 mm from the edge; petiole about 30 cm long.²
INFLORESCENCE:
Translated from protologue: Spathe erect, shortly tubular at the base, ovate-triangular when spread, narrowed scarcely to the middle, 22-25 cm long, 11 cm wide above the base, pale rose with deep rose veining, the tube deep purple; peduncle 40 cm long, fairly stout. Spadix 14-18 cm long; female zone 3-5 cm long, terete, 8-10 mm thick; male zone about 4.5 cm long; appendix stout, conical-subulate, 5-10 cm long, 1 cm thick above the base. Anthers of the stamens very densely arranged, obovoid, with a blunt truncate apex 1.5 mm across, opening by opposite orbicular pores. Ovaries not touching one another at the base, ovoid, narrowed at the apex into a slightly shorter style; stigma cushion-shaped, nearly hemispherical, granular, not lobed.²
ETYMOLOGY:
From Latin napus, “turnip,” with the suffix-ger, “bearing”: the turnip-bearing Amorphophallus. Gagnepain singled out the tuber as the species’ rarest character in the genus - elongate and napiform, sinuous, alternately swollen and constricted along its length.²
NOTES:
1. Amorphophallus napiger differs from Amorphophallus tonkinensis in its much less decurrent leaf segments, a peduncle twice as long, a male zone that is not obconic, staminal pores that are not confluent and, above all, an appendix narrower than the staminate zone.²
2. Hair-like staminodes occur on the appendix, but only occasionally. Among the species that carry them it is recognised by widely spaced pistils with an entire stigma, a spathe limb pale green or, rarely, uniformly purple within, and a very narrow, often branching tuber.⁴
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus napiger Gagnep.
2. Notulae Systematicae (Paris) 9: 119 (1941) — protologue.
3. Alan Galloway — Amorphophallus napiger, alangallowaybotanicals.com.