AMORPHOPHALLUS 'JOHN TAN'

PARENTAGE:

Amorphophallus variabilis x Amorphophallus titanum

ORIGIN:

Cross made by Ralph D. Mangelsdorff on May 23rd, 2002, by applying pollen of Amorphophallus titanum to Amorphophallus variabilis; named by Cyrille Claudel and described in Aroideana in 2012 by Claudel, Mangelsdorff and Wilbert Hetterscheid.

HYBRIDIZER:

Ralph D. Mangelsdorff

DESCRIPTION:

The tuber is depressed globose, at least 24 cm across and about 6 kg, and produces no offsets.¹ The petiole reaches 1.45 m and carries large whitish lichen-like spots like those of Amorphophallus titanum, while the leaf blade, up to 1.20 m across, is poorly dissected in young plants and highly dissected, like Amorphophallus variabilis, in mature ones.¹ The spathe is up to 45 cm long and rich purple-red in its upper inner part, and it surrounds a dirty yellowish-white appendix about 80 cm long whose expanded base overarches the male zone as in Amorphophallus titanum.¹ Claudel summarizes the plant as combining the bold scale and mottled petiole of Amorphophallus titanum with the finer foliage and dense floral structure of Amorphophallus variabilis.¹

HYBRIDS:

Amorphophallus boyceanus × Amorphophallus 'John Tan'

Amorphophallus titanum × Amorphophallus 'John Tan'

NOTES:

1. Claudel's Network page calls it the first registered Amorphophallus hybrid.³

2. Alan Galloway's gallery shows it under accession AGA-2471-01, photographed from September 22nd, 2013 to February 18th, 2019.⁴

3. One of the named seedlings of Amorphophallus variabilis × Amorphophallus titanum.¹ Other named hybrids from the same two species: 'DiGeSt'. See every recorded cross of these two parents.

STORY:

STORY TITLE: Rescued from nematodes and brought to flower in Hamburg

On May 23rd, 2002, Mangelsdorff put pollen of Amorphophallus titanum on the stigmas of one inflorescence of Amorphophallus variabilis.¹ The berries took about five months to ripen and held five viable seeds among many sterile, degenerate ones, and although some seedlings died early, two survived.¹ Heavy nematode infestation put the plants at risk, so they were sent in a rescue to Wilbert Hetterscheid, who kept them for a few years in the Amorphophallus research collection of the Wageningen University Botanical Gardens in the Netherlands until they were free of nematodes.¹ When the Wageningen gardens closed suddenly, one plant went to the Botanical Garden of Leiden University and the other, in 2008, to the Botanical Garden of Hamburg University, where Claudel nursed it until it flowered in June 2011.¹ The Hamburg plant is the one that was described; the Leiden plant was alive but had not yet flowered when the registry text was written.¹ Claudel named the cultivar out of gratitude to his friend John Tan for his encouraging help.¹ He adds that Tan's help in bringing these crosses about cannot be overestimated.²

REFERENCES:

1. International Aroid Society Aroid Cultivar Registry: Amorphophallus 'John Tan'

2. Cyrille Claudel, Amorphophallus Hybrids Network: variabilis x titanum (archived June 2017)

3. Cyrille Claudel, Amorphophallus Hybrids Network: Hybrids (archived January 2018)

4. Alan Galloway Botanicals: Amorphophallus 'John Tan'

Photographs submitted to the IAS Aroid Cultivar Registry by Cyrille Claudel

Photos by Ralph Mangelsdorff / Cyrille Claudel, from the Amorphophallus Hybrids Network website

Photos by Alan Galloway