AMORPHOPHALLUS VILLOSUS

PROTOLOGUE: Amorphophallus villosus A.Galloway, Luu, Malkm.-Huss., Prehsler & Claudel, published in Aroideana 42(1): 42 (2019).

Amorphophallus villosus A. Galloway, Luu, Malkm.-Huss., Prehsler & Claudel sp. nov. Type: from a plant cultivated by A. Galloway (orig. coll.: Vietnam, Đồng Nai Province), 21 May 2017, Galloway AGA-2583-01-T (holotype, SGN, spirit collection).

DISTRIBUTION: Vietnam: Vietnam.

DISTRIBUTION NOTE: Vietnam: Đồng Nai Province, one locality only.².

SPECIES DESCRIPTION:

Tuber depressed globose, to 25 cm across and 12 cm high, dark brown, producing no offsets. Leaf solitary; petiole to 150 cm long and to 7 cm across at the base, roughish with faint grooves, the ground olive brown to rust with many irregularly shaped rosy-cream to greenish-beige spots 0.2-2 cm high and 0.2-1 cm wide. Lamina to 190 cm across; leaflets elliptic, acuminate, 27 cm long and 11.5 cm across, mid-green above with pink margins as the leaf emerges, fading to whitish, pale green beneath.²

INFLORESCENCE:

Inflorescence solitary; peduncle to 100 cm long and to 4 cm across at the base, coloured as the petiole. Spathe 28-30 cm long and 23 cm wide, the kettle and limb separated by a constriction; outside the base pale brownish green, the kettle outside with beige spots 2-4 mm across, inside burgundy with conical irregular warts and ridges; the limb outside with smaller beige spots 1-2 mm across, inside pale burgundy to olive with scattered cream spots about 1 mm across. Spadix much longer than the spathe, 70 cm long; female zone cylindric, 6 cm long and 3.2 cm across including the styles, the flowers distant to somewhat congested and more densely set towards the top; no sterile zone between the female and male zones; male zone cylindric, 10 cm long and 3.5 cm across, the flowers congested and bearing protruding thread-like burgundy staminodes; appendix elongate-conical, to 55 cm long and 4 cm across at the base, rust brown with an acute top, the lowest 1-3 cm with vertical ridges and short grooves along its whole length, covered with thread-like burgundy staminodes and held roughly horizontally or pointing slightly upwards. Ovaries globose, circular in cross section, about 4 mm high and 3.5 mm across, dark burgundy, bilocular; style about 2.5 mm long and 1 mm across, terete, dark burgundy; stigma oval, about 2 mm high and 3 mm across, distinctly two-lobed to saddle-shaped, the surface slightly granular to papillate, grey. Stamens about 3 mm long, the anthers creamy-white with a burgundy connective; filaments about 1.8 mm long; anthers about 1 mm across.²

ECOLOGY:

Known from a single site on a south-facing mountainside, growing at the foot of large boulders in rather cool, rich dark loam, with the leaf blades in full sun.²

ETYMOLOGY:

From Latin villosus, “shaggy.” The whole appendix is clothed in thread-like staminodes, and the epithet records how it looks.²

NOTES:

1. It is one of nine species whose appendix is entirely covered in hair-like staminodes. The others are Amorphophallus barbatus, Amorphophallus cirrifer, Amorphophallus crinitus, Amorphophallus hirtus, Amorphophallus laoticus, Amorphophallus longicomus, Amorphophallus natolii and Amorphophallus pilosus. All belong to subgenus Metandrium and all show a pink or whitish leaf margin.²

2. The authors suggest the resemblance of such an appendix to mammalian skin may play a part in deceiving pollinators.²

3. Against its nearest relatives it is separated as follows: from Amorphophallus pilosus by a depressed globose rather than elongate broad tuber, and by the absence of thread-like staminodes in the female zone - a character confined to Amorphophallus aberrans, Amorphophallus cirrifer and Amorphophallus pilosus; from Amorphophallus pilosus and Amorphophallus hirtus by a much longer style; from Amorphophallus hirtus and Amorphophallus longicomus by the absence of a sterile zone between the female and male zones; and from Amorphophallus laoticus by a depressed globose rather than markedly elongate tuber and elliptic rather than linear-lanceolate leaflets.²

4. The spadix reaches 70 cm, of which the appendix alone is up to 55 cm.²

REFERENCES:

1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus villosus A.Galloway, Luu, Malkm.-Huss., Prehsler & Claudel

2. Aroideana 42(1): 42 (2019) — protologue.

3. Alan Galloway — Amorphophallus villosus, alangallowaybotanicals.com.