AMORPHOPHALLUS EICHLERI
PROTOLOGUE: Amorphophallus eichleri (Engl.) Hook.f., published in Curtis' Botanical Magazine 115: t. 7091 (1889).
Amorphophallus (Hydrosme) Eichleri; folio 3-secto segmentis lateralibus 2-partitis terminali 3-partito partitionibus pinnatifidis v. pinnatisectis, foliolis utrinque 2–3-oblongis ovatis obovatisve acuminatis basi cuneatis marginibus undulatis, rachibus late alatis, petiolo tereti laevi viridi, pedunculo brevissimo vaginis latis laxis membranaceis spatham aequantibus, spathae tubo hemispherico subventricoso sordide albo ore obliquo, intus sanguineo-purpureo infra oram albo, margine dilatato recurvo irregulariter lobulato et undulato fusco-purpureo, spadice subsessili, parte feminea brevi, floribus parvis, parte mascula cylindracea lutea, appendice erecto 4–5-pollicari elongato conoideo basi angustato subrugoso pallide brunneo, ovariis depresso-globosis 2–3-locularibus, stigmate majusculo subgloboso sessili 2–3-lobulato, staminibus cuneiformibus.
SYNONYMS:
HOMOTYPIC SYNONYMS: Hydrosme eichleri Engl. in Jahrb. Königl. Bot. Gart. Berlin 2: 285 (1883)
DISTRIBUTION: W. DR Congo, Angola ?: DR Congo.
Doubtfully present in Angola.
DISTRIBUTION NOTE: Kwango (Cuango) River, historical Fürst Bismark Island, near the Kuhu/Cugo (Cugho) River, present-day Angola–DR Congo border region; ca. 7.4° S, 17.1° E.
SPECIES DESCRIPTION:
Tuber depressed globose, rose-coloured (Engler). Petiole eighteen inches high, cylindric, smooth, green; leaf-blade trisect, divisions shortly petiolulate, a span long, the lateral bisect, the middle one trisect; segments pinnatifid, rachis broadly unequally winged from the base upwards; leaflets two to three pair, sessile by a broad base, elliptic-ovate, acuminate, or the lower obovate, dark green with impressed nerves, margins beyond the intramarginal nerve undulate, terminal three or four inches long, lateral shorter less acute.
INFLORESCENCE:
Peduncle very short, green, sheaths as long as the spathe, lax, very broadly ovate, acute, concave. Spathe one and a half inch high, and as broad across the hemispheric dirty-white striated tube; mouth rather contracted, oblique, margin broadly everted prolonged at one side into a broad tongue-shaped obtuse limb, waved and irregularly crenate or lobulate, dull red brown; interior of spathe mottled with bright red from the base to within half an inch of the everted margin, the intervening space dull white. Spadix nearly six inches high, erect; female portion very short; male longer, cylindric, nearly an inch long; appendix an elongate dull pale brown rugose subacute cone contracted towards the base. Stamens densely crowded, cuneiform with rounded angles, yellowish, two-celled. Ovaries minute, sessile, green, depressed globose, two- to three-celled; cells one-ovuled; stigma globose, two- to three-lobed
DISTRIBUTION MAPS:
ETYMOLOGY:
Named in honor of August Wilhelm Eichler (1839–1887), German botanist, plant taxonomist, and director of the Royal Botanic Garden and Botanical Museum in Berlin, where the species first flowered in cultivation in 1882.
NOTES:
1. Historical locality and mapping uncertainty
The type locality of Amorphophallus eichleri is a small geographical mystery left behind by a nineteenth-century expedition. In 1880–1881, the Prussian officer and naturalist Alexander von Mechow led an expedition through northern Angola toward the Kwango (Cuango) River, accompanied by natural-history collectors including Julius Eduard Teusz. The expedition made extensive zoological and botanical collections while also surveying a region that was, from a European cartographic perspective, still very poorly mapped. Mechow later published an unusually detailed, 26-sheet map of the journey at a scale of 1:81,200. His records include an island in the Kwango called “Fürst-Bismark-Insel”—literally “Prince Bismarck Island.”
It was from this island that Teusz obtained the material later associated with Amorphophallus eichleri. Living roots reached the Berlin Botanic Garden in 1880 and the plant flowered there in 1882, leading Adolf Engler to describe it as Hydrosme eichleri in 1883; Joseph Dalton Hooker later transferred it to Amorphophallus. When N. E. Brown treated the species in the Flora of Tropical Africa in 1901, he gave its provenance unambiguously as “Lower Guinea. Angola: Bismark Island, in the River Kuango, cultivated specimens, Teusz.”
The difficulty comes when that nineteenth-century locality is translated onto a modern political map. The expedition occurred before the present Angola–Congo boundary had been formally delimited, and the Kwango itself later became part of the international frontier between Angola and what is now the Democratic Republic of the Congo. The boundary agreements and surveys that established the modern frontier largely postdate Mechow's journey. An island lying within the river therefore cannot automatically be assigned to Angola simply because the expedition approached it from Angola, nor to the DRC simply because a later boundary placed that portion of the river within or alongside Congolese territory.
This appears to have produced two competing geographical interpretations in the botanical literature. The early literature treated the locality as Angolan, while modern Kew-derived checklist data have generally treated Amorphophallus eichleri as native to Zaire/DR Congo, with Angola sometimes considered doubtful. Neither interpretation necessarily reflects a different collection: both may be attempts to assign the same historical river island to a modern country.
For this reason, the most defensible treatment is to preserve the original locality rather than force it into a modern national boundary:
Historical locality: Fürst-Bismark-Insel, Kwango (Cuango) River, present-day Angola–Democratic Republic of the Congo border region.
The exact modern position of the island remains uncertain. Mechow's original map provides the best evidence for resolving it, but the historical river channel and nineteenth-century survey would need to be georeferenced against modern hydrography and the international boundary before assigning a precise coordinate or country. Until then, recording the locality as an Angola–DR Congo border locality, while noting the historical attribution to Angola, avoids giving a false impression of precision.
2. From Aroideana 8: "A recent collection of Amorphophallus eichleri (Eng\.) Hook. f. (J. Lewalle 4009; at K) from Burundi in central Africa differs from other specimens of the species only by the presence of numerous wart-like (verrucose) projections covering the surface of the appendix. It may perhaps be a "throw-back" or monstrous specimen of an otherwise smooth-appendixed species. A rather different-looking type of staminodial structure is found in the appendix of Amorphophallus aphyllus (Hook.) Hutch., while in Amorphophallus dracontioides (Eng\.) N.E. Brown, another West African species, the sculpturing of the appendix seems closer to that of the Burundi Amorphophallus eichleri.
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus eichleri (Engl.) Hook.f.
2. Curtis' Botanical Magazine 115: t. 7091 (1889) — protologue.
3. Alan Galloway — Amorphophallus eichleri, alangallowaybotanicals.com.
6. Herder-Institut. Catalogue record for Mechow’s Karte der Kuango-Expedition (1884).
7. Gotha Digital. Catalogue record for Mechow’s Karte der Kuango-Expedition (1884).
10. Flora of Tropical Africa, Volume VIII, searchable text.
11. Hooker, J. D. 1889. Amorphophallus eichleri. Curtis’s Botanical Magazine 115: t. 7091.
12. JSTOR Global Plants. Amorphophallus eichleri, plate 7091.
14. Article Link
15. Figueiredo, E., Smith, G. F. & Dressler, S. 2020. Open-access Naturalis copy.