AMORPHOPHALLUS LANUGINOSUS

PROTOLOGUE: Amorphophallus lanuginosus Hett., published in Blumea 39: 261 (1994).

Amorphophallus lanuginosus Hett., spec. nov. Ab omnibus speciebus in tubere elongato, stigmatibus valde lobatis, staminodiis capillaceis aggregatis inter flores masculos et in zona sterili inter zonas masculas femineasque differt. — Typus: Averyanov & Kudryavtseva 105 (LE holo; iso LE), Vietnam, Phu Khanh Prov., Nha Trang, Hon Tre, 12° 11' N, 109° 16' E, 6-xi-1989.

DISTRIBUTION: Vietnam: Vietnam.

DISTRIBUTION NOTE: Vietnam: Khanh Hoa Province, Nha Trang — Hon Tre Island (only known from the type collection; the type locality lies in the former Phu Khanh Province)².

SPECIES DESCRIPTION:

Tuber elongate, length unknown, diam. of top part c. 3 cm. Leaf unknown.²

INFLORESCENCE:

Inflorescence solitary, long peduncled; peduncle 54-55 cm long, c. 0.7 cm in diam., mottled; spathe erect, elongate triangular-ovate, acute, 13 cm long, 4.5-5 cm in diam., base within with numerous, very irregular verrucae, especially on the dorsal side. Spadix sessile, much longer than the spathe, 25-35 cm long; female zone cylindric, 1.8-2.8 cm long, c. 0.7 cm in diam., flowers congested; male zone obconic, 2.5-3 cm long, c. 0.5 cm in diam. at the base, c. 0.9 cm in diam. at the top, flowers distant, in between surrounded by masses of staminodes with long, flexuous hairs, nearly entirely covering the male zone and hiding the flowers from sight; sterile zone between female and male zone 0.5-0.8 cm long, with sterile male flowers sunken in deep, longitudinally elongate pockets, hairlike appendages of flowers extruding from the pockets; appendix elongate fusiform, acute, base constricted, smooth, 20-27 cm long, c. 1.5 cm in diam. (at one-third from the base). Ovaries diamond-shaped in cross section, depressed, sunken in spadix axis, c. 3 mm in diam., c. 1.5 mm high, bilocular; style very short, c. 0.5 mm long, c. 0.5 mm in diam.; stigma very flattened, more or less diamond-shaped or star-shaped in cross section, sides concave, c. 2 mm in diam., c. 0.5 mm high, with a deep central depression and mostly four-lobed, surface rugulose. Male flowers basically consisting of c. 5 or 6 stamens; stamens c. 1 mm long; filaments c. 0.5 mm, connate; anthers c. 0.5 mm, truncate, pores apical, elongate to oval; staminodes in male zone mostly between male flowers but also within male flowers, consisting of a conic basal part, representing a reduced stamen, strongly laterally flattened, on the top a long, flexuous, translucent hair of 2.5-3 mm long; staminodes of the sterile zone distinctly grouped in numbers of c. 6, representing reduced entire male flowers. Pollen psilate.²

ETYMOLOGY:

The species epithet refers to the woolly appearance of the male zone.²

NOTES:

1. Due to the peculiar morphology of the male zone, Amorphophallus lanuginosus cannot easily be mistaken for any other species. Its morphological affinity is to Amorphophallus macrorhizus (northern Thailand) and Amorphophallus cruddasianus (northern Myanmar). It differs from both in the aforementioned character but also in the differently shaped stigma and the irregular warts in the spathe-base.²

REFERENCES:

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

2. Blumea 39: 261 (1994) — protologue.

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