AMORPHOPHALLUS MANGELSDORFFII
PROTOLOGUE: Amorphophallus mangelsdorffii Bogner, published in Willdenowia 33: 299 (2003).
Amorphophallus mangelsdorffii Bogner, sp. nova Differt a Amorphophallo antsingyense stigmate parvo, spinulis pollinis brevioribus et laxioribus dispositis, lamina spathae recurvata et torta, lamina folii minus dissecta foliolis pro rata magnis, inflorescentia cum folio ad finem temporis pluvialis oriens. — Holotypus: Madagascar, Tsingy du Maintirano, 8 km east of the village Tsimaloto and c. 80 km southeast of Tambohorano, c. 300 m, flowering with leaf, 18.3.2001, R. Mangelsdorff RMM 550 (M; isotypi: FR, K).
DISTRIBUTION: Madagascar: Madagascar.
DISTRIBUTION NOTE: Madagascar: the Tsingy du Maintirano in the west, near the village Tsimaloto — only known from the type locality².
SPECIES DESCRIPTION:
Tuber depressed-globular, 4.5-6 × c. 3 cm, somewhat sunken in the centre, smooth, dark brown outside, yellow inside. Petiole 32-48 cm long, at the base c. 0.8 cm and apically 0.4-0.6 cm in diam., light green, sheath c. 14 cm long. Leaf blade dissected in three main parts only, each either ± bifid and arising directly from the apex of the petiole, or once more divided and each leaflet with a petiolule 3 cm long and 0.3-0.4 cm in diam.; leaflets 9-14 × 2.5-4 cm, narrowly elliptic to lanceolate, decurrent, green on the upper and lighter green on the lower surface, base mostly somewhat oblique, apex acuminate; venation reticulate, inner collecting vein 1.5-2 mm from the margin of the leaflet.²
INFLORESCENCE:
Peduncle 17-27 cm long and 0.4-0.8 cm in diam., light green as the petiole and never spotted. Spathe 7-9 cm long, c. 3.5 cm wide, only very slightly constricted or nearly so, initially upright, later limb reflexed and twisted, convolute at base and forming a subglobular tube of 1.5-2 cm diam., outside light green at base and then becoming greenish yellow, inside at base of the tube greenish and smooth with somewhat prominent veins, then becoming greenish yellow to ± cream, apex acute. Spadix clearly longer than spathe, 10-12 cm long, sessile; pistillate portion short, c. 0.5 cm long and 1.1 cm in diam., flowers in up to four spiral rows; staminate portion c. 1.7 cm long and 1.3 cm in diam., yellow to somewhat beige; pistillate and staminate flowers contiguous; appendix elongate-conoid to subcylindric, 8.5-9.5 cm long, greenish yellowish on the whole length. Staminate flowers densely arranged; connective broad, rounded apically, somewhat higher than the thecae; thecae lateral, golden yellow, opening by an apical slit; pollen inaperturate, globular, 38-42 µm in diam., exine echinate, spinulae small and lax. Pistillate flowers densely arranged; ovary ovoid, light green, whitish at base, unilocular; stigma small, subhemispheric, sessile, 0.6-0.7 mm in diam., whitish, papillose. Infructescence unknown. Odour at anthesis like fermenting fruits and somewhat spicy.²
ECOLOGY:
A geophyte growing in leaf-litter filled holes and crevices on limestone (tsingy) in tropical deciduous forest, together with Pachypodium, Disperis, Habenaria and Dracaena reflexa; the limestone overlies an old sandstone plateau²
ETYMOLOGY:
Dedicated to Ralph Mangelsdorff, opera singer, student of botany and collector of the species.²
NOTES:
1. Amorphophallus mangelsdorffii is closely related to Amorphophallus antsingyensis; both have a spiny (echinate) pollen exine while the other three endemic Malagasy species have a psilate to fossulate exine, and the two form a separate group within the island's fauna of the genus.²
2. All Malagasy Amorphophallus species are confined to the deciduous forests of western Madagascar — none occur in the evergreen rainforests of the east coast, although in tropical Africa and Asia the genus is well represented in rain forests.²
3. The species reached science by way of a bad trip. Ralph Mangelsdorff was in the Tsingy du Maintirano in March 2001 looking for succulents, asclepiads, orchids and aroids when he came on it. Getting out again turned into an ordeal of long walks, a broken leg, a rescue, and three days crossing undeveloped country on a two-wheeled ox cart. The gathering he carried back proved to be new, and the species carries his name.²
4. He found it flowering at the end of the rainy season alongside its single leaf. Every other Malagasy species in the genus flowers leafless, at the end of the dry season or the beginning of the wet one, so the plant announced itself as something unusual before it was ever examined.²
5. Tsingy is the local word for the deeply eroded limestone the plant grows in, and maintirano means black water.²
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus mangelsdorffii Bogner
2. Willdenowia 33: 299 (2003) — protologue.
Additional photos by Bjørn Malkmus-Hussein, Tobias Pfeil