AMORPHOPHALLUS REFLEXUS

PROTOLOGUE: Amorphophallus reflexus Hett. & A.Galloway, published in Aroideana 29: 71 (2006).

Amorphophallus reflexus Hett. & A. Galloway, sp. nov. Amorphophalli reflexi flores masculi synantheriati eis Pseudodracontii similes sed pro Amorphophallo s.s. ignoti. Ab omnibus Pseudodracontii speciebus spadice spatha multo longiore, appendice laevi differt. Type: from a plant in cultivation by A. Galloway (orig. coll.: THAILAND, Khampaeng Phet Province, soil pockets in limestone, A. Galloway), 29 July 2005, Galloway AG.II-1069-01-T (holotype, WAG, spirit collection).

DISTRIBUTION: N. Thailand: Thailand.

DISTRIBUTION NOTE: Thailand: Kamphaeng Phet Province - known only from the type locality.².

SPECIES DESCRIPTION:

Tuber elongate, thin, 10-24 cm long, 1-2 cm in diam., rarely branching. Petiole to 40 cm long, 5-7.5 mm in diam., smooth, uniformly rich burgundy red; leaflets elliptic to elliptic-obovate, 2-5 cm long, 1.5-4.5 cm wide, apex acute, upper surface mid green.²

INFLORESCENCE:

Inflorescence solitary; peduncle as petiole, 19 cm long, 0.5 cm in diam.; spathe broadly ovate, 4 cm long, 5 cm in diam., at first erect, then the upper part moving a little away from the spadix at female anthesis, and at male anthesis the lower half reflexing to a position at a right angle with the spadix-axis, pulling the upper part of the spathe further away from the spadix, outside white with a green flush, inside white, base inside densely verruculate; spadix much longer than spathe, 11.5-13 cm long; female zone cylindric, 0.5-0.6 cm long, 0.6 cm in diam., flowers distant; male zone fusiform, 1.5 cm long, 0.9-1 cm in diam., flowers distant; appendix narrowly elongate fusiform, 9-11 cm long, 0.7-0.8 cm in diam. at the middle, base tapering, apex acute, surface smooth, off-white, creamish or pale green. Ovary depressed, oval in cross-section, sunken into the spadix-axis, 1.5-2 mm in diam., slightly bilobed by two opposite, shallow peripheral constrictions, pale green, 2(-3?)-locular; style short, thick, 0.5 mm long, 1 mm in diam.; stigma very thin, 1 mm in diam., 0.1-0.2 mm thick, shallowly bilobed, verruculate, dirty creamish. Male flowers fully synstaminate, consisting of 3-5 fully fused stamens; filaments fused into a column, 1-2 mm long, 2 mm in diam., off-white; anthers fully fused into a disc, 2.5-3 mm in diam., 1 mm high, with a shallow, elongate, central depression, pores lateral, slit-like; pollen few, released immediately after the reflexing of the spathe base and dropped on its horizontal inner surface. Fruiting part elongate, berries crowded; berries ovate to lageniform, smooth, ca. 1 cm long, ca. 1 cm in diam., green when immature, then turning glossy white, 1- to 3-seeded. Seeds subglobose to globose, ca. 5 mm in diam., greenish to blackish.²

ECOLOGY:

Found in soil pockets in limestone²

ETYMOLOGY:

From Latin reflexus, “bent back”: the epithet records what the spathe does at anthesis. It stands erect at first, then at male anthesis the lower half folds back to a right angle with the spadix-axis, so that the pollen falls onto the newly horizontal inner surface.²

NOTES:

1. Diagnosis: the synandrous male flowers of Amorphophallus reflexus resemble those of Pseudodracontium and were unknown in Amorphophallus in the strict sense. It differs from every Pseudodracontium species in a spadix much longer than the spathe and a smooth appendix.²

2. The most remarkable feature is the shape of the male flowers, which imitate those of Pseudodracontium perfectly; every other character is typical Amorphophallus. Where it sits phylogenetically is difficult to say. The white lageniform berries are otherwise unique to the Amorphophallus saururus alliance, but the species lacks that group's leaf characters, and its obovate-elliptic leaflets instead recall the Amorphophallus pusillus alliance.²

3. The very long, thin appendix is as extreme as in Amorphophallus linearis, Amorphophallus elatus, Amorphophallus lanuginosus and Amorphophallus operculatus.²

REFERENCES:

1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus reflexus Hett. & A.Galloway

2. Aroideana 29: 71 (2006) — protologue.

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