AMORPHOPHALLUS MAXWELLII

PROTOLOGUE: Amorphophallus maxwellii Hett., published in Blumea 39: 263 (1994).

Amorphophallus maxwellii Hett., spec. nov. A speciebus omnibus in stylis longissimis 8-9 mm longis, spatha magna campanulata, appendice longissima tenui differt. — Typus: T. Yamazaki 4515 (TI holo), Thailand, Kanchanaburi Prov., foot of mountain in eastern part of Thong Pha Phum, alt. 700 m, in mixed deciduous forest under bluff of limestone, 10-v-1983.

DISTRIBUTION: SW. Thailand: Thailand.

DISTRIBUTION NOTE: Thailand: Kanchanaburi Province (the type from Thong Pha Phum, at 700 m under a limestone bluff)².

SPECIES DESCRIPTION:

Tuber subglobose to depressed-globose, ca. 10-23 cm in diam. and 12-14 cm high, outside dark brown, distinctly glossy, producing annual, long rhizomatous offsets. Leaf solitary; petiole to 80 cm long, ca. 3 cm in diam., silvery white with irregular dark emerald-green spots; lamina ca. 100 cm in diam.; leaflets elongate-elliptic, to ca. 20 cm long, ca. 13 cm in diam.⁴

INFLORESCENCE:

Inflorescence long-peduncled; peduncle smooth, 18-100 cm, ca. 1-2 cm in diam., as petiole; spathe subcampanulate, broadly ovate to elongate-elliptic, 27-69 cm long, 13-30 (or more?) cm in diam., base and limb separated by a very shallow constriction, base convolute and slightly laterally compressed, limb at first oblique then the top strongly arching forward, top acute, margins strongly sinuous, limb outside lower half pale cream with dull violet stains, upper half very dark maroon, inside lower half cream or purple, upper half very glossy dark maroon, base inside dark maroon, upper part dirty creamish, basal part densely clothed with fleshy, elongate, often hair-like warts. Spadix sessile, slightly or distinctly longer than spathe, 30-82 cm long.⁴

ECOLOGY:

Found on limestone, in mixed deciduous forest, in partly shaded areas⁴

PROPAGATION:

We had poor luck with this species, rooting only 3.3% from both early September and mid-October cuttings. Even with proper timing, this was among the most difficult species to root.

ETYMOLOGY:

Named in honor of Dr. J. F. “Max” Maxwell, a field botanist associated with Chiang Mai University whose frequent collecting trips and detailed observations contributed greatly to the study of Thai Amorphophallus. Hetterscheid specifically acknowledged Maxwell’s extensive field observations, and the species itself was one of Maxwell’s discoveries.

NOTES:

1. Amorphophallus maxwellii resembles Amorphophallus konjac but the latter has shorter styles, 2-3-locular ovaries, the appendix diameter at the base distinctly larger than the diameter of the male zone, and a spathe that does not bend over. The active moving of the spathe limb after female anthesis is also found in the Philippine Amorphophallus declinatus, which also resembles Amorphophallus maxwellii quite strongly but has sessile stigmas. It is a very ornamental species because of its strikingly colored petiole and peduncle as well as the large, dark maroon spathe.⁴

2. The styles, at 8-9 mm, are the longest in the genus — the character Hetterscheid's Latin diagnosis leads with.²

REFERENCES:

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

2. Blumea 39: 263 (1994) — protologue.

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

4. Aroideana 19 (1996):P7 - 131

5. Propagation of Amorphophallus by Leaf Petiole Cuttings — Juniper Level Botanic Garden