AMORPHOPHALLUS NICOLAII

PROTOLOGUE: Amorphophallus nicolaii Hett., published in Aroideana 36: 90 (2013).

Amorphophallus nicolaii Hett., sp. nov. Type: VIETNAM (no further data, but probably north), Hetterscheid H.AM.1614-T (holotype, L, spirit coll.), prepared from a cultivated plant, originally collected by the late Dr. Nicolai Arnautov (# 03275) of the St Petersburg Botanical Garden (Russia) and cultivated in the Leiden Botanical Garden (The Netherlands).

DISTRIBUTION: Vietnam: Vietnam.

DISTRIBUTION NOTE: Vietnam, without further locality data but probably the north of the country; the holotype was prepared from a plant grown on in the Leiden Botanical Garden.².

SPECIES DESCRIPTION:

Tuber depressed globose, singular, 8 cm in diam., 4.5 cm high, bright purple. Petiole smooth, 46 cm long, 11 mm in diam., uniformly dark olive green; lamina 70 cm wide, rachises only winged in the distalmost parts; leaflets elongate ovate to elongate elliptical, 6-22 cm long, 2-6.5 cm wide, long acuminate, upper surface mid green, semi-glossy.²

INFLORESCENCE:

Peduncle 21 cm long, very dark green with numerous, small, narrowly elliptical blackish spots; spathe erect, not constricted, 15 cm long, 13.5 cm wide, acute, basal part convolute, outside mid greyish green with numerous small, orbicular blackish green spots and very faint, irregular, larger paler green spots, veins strongly impressed, inside pale green with paler areas and in the lower part scattered, small, slightly irregular blackish green dots, basal part with a short zone of congested, small, conical verrucae. Spadix sessile, nearly as long as spathe, 13.8 cm long; female zone cylindric, 1.3 cm long, 1.6 cm in diam., flowers congested; male zone cylindric, 5 cm long, 1.5 cm in diam., slightly laterally compressed, flowers densely congested; appendix inflated, conical, 7.5 cm long, 3 cm in diam. at the base, tapering to the top, base strongly truncated, top obtuse, surface slightly corrugate, off white, emitting a strong almond scent at female anthesis. Ovaries depressed, 2.5 mm high, 3.5 mm in diam., pale green, bilocular; style cylindric, 1 mm long, 0.8 mm in diam., pale green; stigma depressed, orbicular in cross-section, 2 mm in diam., 1 mm high, surface minutely verrucate, off white. Stamens all free, not visibly clustered into multi-staminate flowers, 1.2-2 mm in diam., 2 mm long; filaments free, 0.5 mm long; anthers 1.5 mm long, off white; pores slit-like, apical, with a groove running from the middle of the pore to the margin of the anther.²

ETYMOLOGY:

Named after Nicolai Arnautov of the St Petersburg Botanical Garden, who on a 1992 visit gave a number of unidentified Amorphophallus plants to the first author’s research collection - among them the one that later yielded the holotype.²

NOTES:

1. Diagnosis: morphologically close to Amorphophallus croatii of Laos, but differing in a purple-reddish, glossy tuber, a much longer male zone, an appendix almost twice as broad at the base, and free filaments whose anthers are not clearly grouped.²

2. The species is known from the type alone, and the plant that produced it had already passed through two botanical gardens - collected in Vietnam, grown in St Petersburg, then grown again in Leiden - so no habitat, altitude or precise locality was ever recorded for it.²

REFERENCES:

1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus nicolaii Hett.

2. Aroideana 36: 90 (2013) — protologue.