AMORPHOPHALLUS JOSEFBOGNERI

PROTOLOGUE: Amorphophallus josefbogneri Hett., published in Aroideana 29: 60 (2006).

Amorphophallus josefbogneri Hett., sp. nov. Type: collected from a plant cultivated in the Botanical Gardens of Wageningen University (orig. coll.: THAILAND, Kanchanaburi Province, on an unnamed table mountain near the Burmese border, Sappasiri Chaovanich s.n.), 24 June 2005, Hetterscheid H.AM.1396-T, (WAG, holotype, WAG, spirit collection).

Hic folii coloribus texturaque, spathae margine incurvo Amorphophalli saururi grege valde pertinet, ab omnibus eis foliis textura maxime crassa petiole brevissimo differt. Hic character Amorphophallo pygmaeo communicat, sed Amorphophallus josefbogneri folii latere inferiore atropurpureo caret et quoque tuber multo longior tenuior.

DISTRIBUTION: SW. Thailand: Thailand.

DISTRIBUTION NOTE: Thailand: Kanchanaburi Province (an unnamed table mountain near the Burmese border).

SPECIES DESCRIPTION:

Tuber narrowly elongate, branching, to 13 cm long, to 1.5 cm in diam., rhizomorphic, white. Petiole short, 8–9 cm long, 2–4 mm in diam. smooth, uniformly dull green to greyish-green; lamina to 19 cm in diam., few leaflets, rachises short, winged all over; leaflets elliptic to slightly elongate obovate, 5–10 cm long, 2–5 cm in diam., slightly leathery, apex acute, upper surface dark rich green with narrow purple margin, lower surface greyish-green.

INFLORESCENCE:

Peduncle 16 cm long, 6 mm in diam. at the base, smooth, lower part very pale brown grading upwards to uniformly pale green. Spathe cymbiform, ovate, 8 cm long, 6 cm wide, base and limb not separated, short and loosely convolute, apex acute, margins slightly concave, outside base pale green, grading upwards to off-white, apex pale greyish-green, inside base pale green, grading upwards to whitish green, base within densely set with fleshy, irregularly elongate, verruculate warts. Spadix longer than spathe, 11 cm long; female zone cylindric, 1 cm long, 7 mm in diam., flowers distant; male zone subcylindric, slightly tapering to the apex, 3 cm long, 8 mm in diam., flowers congested; appendix narrowly elongate-conical, 7 cm long, 9 mm in diam., distinctly bent forward, base constricted, apex subacute, surface rugulose, off-white, emitting a strong scent of oligimethyl-oligosulphides at female anthesis. Ovary depressed, 2 mm in diam., 0.8–1 mm high, unilocular, pale green; style short, directed upwards at ca. 45 degrees, ca. 0.4 mm long, ca. 0.6 mm in diam., whitish green; stigma depressed, subtriangular to irregular in outline, weakly 2–3-lobed, 1–1.2 mm in diam., ca. 0.4 mm high, verruculate, off-white. Male flowers consisting of (2–)3–4(–5) stamens; stamens very short, 0.6 mm high, 2–3 mm in diam.; filaments almost absent, 0.1 mm, fused, off-white; anthers ca. 0.5 mm long, truncated, off-white, pores apical, slit-like.

ETYMOLOGY:

Named in honor of Josef Bogner (1939–2020), the German aroid specialist of the Munich Botanical Garden. In the protologue Hetterscheid wrote: “The species is named after my friend and greatest aroid scientist alive, Josef Bogner, Doctor Honoris Causa at the Munich Botanical Garden, now retired but never at rest.”

NOTES:

1. Amorphophallus josefbogneri is obviously a member of the Amorphophallus pygmaeus alliance, identified by the deep rich green leaves with narrow reddish-lilac margin, the concave white spathe with incurved margin. The very short-petioled, extremely thick-textured leaves are matched only by Amorphophallus pygmaeus Hett. (C. and S. Thailand) itself but the latter has the lower surface of the leaves a rich deep reddish-purple and a much smaller tuber, which is either subglobose or only very shortly elongate.

REFERENCES:

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

2. Aroideana 29: 60 (2006) — protologue.

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