AMORPHOPHALLUS COAETANEUS

ORIGINAL DESCRIPTION:

CLIMATE: N/A

ECOLOGY: Moist forested valleys, along water, thickets; 300-900 m. Guangxi (Guiping, Rongshui), Yunnan [E and N Vietnam].

SPECIES DESCRIPTION:

Tuber persistent, dark brown to blackish, depressed globose, to 3 cm high, to 6 cm in diam., chained with others to form a pseudorhizome of 2-6 modules, each 3-5 cm in diam. Leaves 1-3, lasting up to 3 years; petiole uniformly dark green, terete, 60-120 × 1-2 cm, turgid, glabrous; leaf blade to ca. 100 cm in diam.; rachises only winged distally, common base of 3 main branches sometimes developing into an intercalary bulbil; leaflets dark green, oblanceolate, 15-20 × 4-6 cm, acuminate.

INFLORESCENCE:

Inflorescence long pedunculate; peduncle colored as petiole, 10-50 × 0.6-1.3 cm. Spathe shortly convolute at base, outside green, dirty green flushed with dirty brownish purple or distal half entirely brownish purple; inside uniformly green or background color dirty green, at base and along midrib flushed dirty dark purplish, near apex less so, or base pale green and rest flushed with brownish purple, narrowly triangular to triangular-ovate, 7.5-15 × 3-7 cm, base within glabrous or nearly glabrous with a few scattered, small, punctiform warts, apex acute. Spadix giving off a heavy gaseous stench at female anthesis, sessile, pale yellowish green with a very faint greenish flush, as long as or longer than spathe, 10-19.5 cm; female zone cylindric, 1-2 × 1-1.6 cm, flowers congested; ovary green or pale whitish green, strongly depressed, depressed globose, or subglobose, 1.5-2 mm high, 1.5-4 mm in diam., angulate or irregularly orbicular in cross section, 1- or 2-loculed; style straight or slightly upcurved, pale green, 1-2 × ca. 0.8 mm; stigma pale yellowish or pale greenish, flattened, disciform or nearly so, 0.7-0.8 mm high, 0.8-2 mm in diam., irregularly orbicular or elliptic in cross section, entire with a shallow, elongate, central depression or shallowly 2-lobed, or more distinctly bilabiate, margin with 2 small notches or a few small lobes, densely verruculose or echinulate; male zone cylindric, apex slightly widened, terete or slightly compressed, 2.3-4.5 × 0.7-1.5 cm, flowers congested; male flowers consisting of 3 or 5 stamens; stamens ca. 2 × 1-2 mm; filaments ca. 0.7 mm, connate or largely free; anthers off-white, ca. 1.3 mm, truncate; pores apical, elongate and connected to margin of anther by a groove; appendix narrowly fusiform-conic, 5.5-14.5 cm, base 0.7-2.3 cm in diam., sometimes slightly compressed, glabrous or shallowly corrugate, base glabrous or with some flattened staminodes, separated by grooves, base constricted, apex acute. Fruiting zone at least 5 × ca. 4 cm. Berries dark blue, oval or oval-ellipsoid, ca. 1 × 0.8 cm, 1- or 2(or 3)-seeded. Fl. Mar.

VARIEGATED FORMS: N/A

PROPAGATION:

Cuttings from this species rooted at 45.8% for cuttings taken in April. Juniper Level Botanic Garden expected this evergreen species to root throughout the season, but best percentages will probably come in early summer. Bulbils in the main leaf axis are clone-dependent in Amorphophallus coaetaneus: Wilbert Hetterscheid wrote that some clones form them and others do not. His advice was to leave the bulbils on the leaf until it has died back completely, then plant them.⁸

ETYMOLOGY: The species is named after Mr. Cyrille Claudel of Germany for his extensive work on the molecular phylogeny of Amorphophallus, numerous documented experiments of hybridization of Amorphophallus species and his cheerful willingness of sharing the results of his ongoing work.

NOTES:

1. In this species, the inflorescence and leaf are present at the same time, which is rare and distinctive among Amorphophallus

2. The inclusion of Amorphophallus arnautovii and Amorphophallus pingbianensis in the synonymy of Amorphophallus coaetaneus has been published and discussed by Hetterscheid and van der Ham (Blumea 46: 279-281. 2001).

3. In the protologue of Amorphophallus coaetaneus, the specific epithet was given in error as "guipingensis" in the figure caption on p. 186.

4. Guangxi: Guiping County, Daping Mountain, elevation 450 m, under forest in valleys, beside water or in moist places. Liu Shouyang and Wei Songji 001978; same locality, Liu Shouyang and Wei Songji 002211, flowering type, preserved at Guangxi College of Traditional Chinese Medicine, with an isotype of the same number preserved at Guangxi Institute of Botany; Rongshui County, Sirong Commune, Liu Shouyang and Wei Songji 001116, fruiting; Yulin County, Zhangmu Commune, Liu Shouyang and Wei Songji 002095.

5. Growers indicate Amorphophallus coaetaneus inflorescences smell strongly of sulphur/methane gas

6. In cultivation, Wilbert Hetterscheid described Amorphophallus coaetaneus as an evergreen species whose leaves may stay on for 3–5 years, and advised keeping it in growth and refreshing the soil every 2 years.⁹

7. In Mobile, Alabama (USDA zone 8b), Russell Coker planted two Amorphophallus coaetaneus in the garden in the summer of 2009, after years of moving them in and out of a friend's greenhouse. Once frost had cut the leaves back he covered them with oak leaves, and they came through the coldest, wettest winter in recent memory, which included several nights in a row in the 20s°F. Both returned in spring 2010, the first emerging with a flower, his first for the species, and leaves on both followed about two months later.¹⁰,¹¹ Wilbert Hetterscheid had stated in December 2006 that the species is not hardy at all.⁹

CULTIVARS: N/A

HYBRIDS:

• Amorphophallus coaetaneus × Amorphophallus ochroleucus