AMORPHOPHALLUS STUHLMANNII
PROTOLOGUE: Amorphophallus stuhlmannii (Engl.) Engl. & Gehrm., published in Pflanzenr., IV, 23C: 81 (1911).
Amorphophallus Stuhlmannii (Engl.) Engl. et Gehrm., Das Pflanzenreich IV.23C: 81 (1911). Hydrosme Stuhlmannii Engl. in Engler's Bot. Jahrb. XXXIV (1904) 152. Ostafrikanische Steppenprovinz, Zone Ost-Usambara: Unterhalb Lungusa im Schluchtenwald des Sigi, 150 m ü. d. M. (A. Engler, Reise nach Ostafrika. - Blatt Sept. 1902. - Herb. Berlin); im Schluchtenwald bei Amani, 700 m ü. d. M. (B. L. Inst. Amani n. 333 [leg. Warnecke]. - Blütenstand März 1903. - Herb. Berlin); Kwamkujofälle bei Amani (B. L. Inst. Amani n. 1672 [leg. Braun]. - Blütenstand April 1908. - Herb. Berlin).
SYNONYMS:
HOMOTYPIC SYNONYMS: Hydrosme stuhlmannii Engl. in Bot. Jahrb. Syst. 34: 152 (1904)
ACCEPTED INFRASPECIFICS: Amorphophallus stuhlmannii subsp. congoensis (A.D.Hawkes) Ittenb. Amorphophallus stuhlmannii subsp. stuhlmannii
DISTRIBUTION: DR Congo, E. Trop. Africa: Kenya, Tanzania, DR Congo.
DISTRIBUTION NOTE: Tanzania: the East Usambara mountains - below Lungusa in the ravine forest of the Sigi, ravine forest near Amani, and the Kwamkujo falls near Amani in the Muheza and Korogwe districts.² iNaturalist: Iringa, Morogoro.
SPECIES DESCRIPTION:
Translated from protologue: Tuber 2-3 dm across. Petiole of the leaf 2-2.5 m long and 4 cm thick, green with lengthwise white stripes; lamina nearly 3 m across, trisect, the primary segments dichotomous and pinnatisect as far as the fork, carrying on each side 2-3 oblong, long-acuminate segments 8-9 cm long and 4 cm wide alternating with larger ones 2.3 dm long and 7-8 cm wide, all decurrent on the rachis above; secondary segments 1-1.2 m long, bipinnatisect; the lowest tertiary segments nearly 3 dm long and 1 dm wide, oblong-lanceolate, passing at the base into a wing of the rachis 1.5-2 cm wide and alternating with others half their size; the upper tertiary segments pinnatisect, the ultimate segments 1.5-2 dm long in the larger ones and 8-9 cm in the smaller, oblong-lanceolate, acuminate, passing at the base into a very broad wing of the rachis 2-3 cm long; all segments many-veined, the numerous parallel lateral veins joining a collective vein set a little back from the margin.²
INFLORESCENCE:
Translated from protologue: Peduncle about 1.1 m long and 2.5-3 cm thick at the base. Spathe 5 dm long, rolled into a tube 1 dm long, the blade oblong and acuminate with an undulate and pleated margin, purplish; the tube purple within below and densely fibrillose. Spadix two-thirds longer than the spathe; female inflorescence 8 cm long and 2 cm thick, male 4 cm long and 2 cm thick; appendix 7 dm long, 3 cm thick in its lower part, smooth. Male flowers of 2 or 3 stamens; stamens 1.5 mm wide and 1 mm long, sessile, the thecae obovoid, opening by a kidney-shaped apical slit. Pistils a little apart; ovary 3.5-4 mm long and as thick, subglobose, 2- or 3-locular, each chamber bearing a single thick, sessile, anatropous ovule; style very short, scarcely 1 mm long, crowned by 2 or 3 thick, broadly triangular stigmas 2 mm long.²
ECOLOGY:
Recorded from ravine forest - in the ravine forest of the Sigi at 150 m, in a ravine forest near Amani at 700 m and at 650 m in. Flowering material was gathered in March and April, and leaves in September.²
ETYMOLOGY:
Named in honor of Franz Ludwig Stuhlmann (1863–1928), German naturalist, zoologist, botanist, and explorer whose expeditions produced extensive scientific collections from East Africa. The Latinized epithet stuhlmannii means “of Stuhlmann,” and is particularly appropriate for a species centered in tropical eastern and central Africa.
NOTES:
1. The species was first published as Hydrosme stuhlmannii in 1904 and moved into Amorphophallus by Engler and Gehrmann in 1911.²
2. It is one of the largest-leaved species in the genus. A single leaf reaches nearly 3 m across on a petiole 2-2.5 m tall, and the leaf is divided four times over - the primary segments fork, the secondary segments are twice pinnatisect, and the tertiary ones are pinnatisect again.²
3. The appendix alone is 7 dm long, well over half the length of the whole spadix.²
4. The ovary has two or three chambers, each with a single ovule, and the style is so short that the stigmas sit almost directly on it.²
5. Engler figured the species as Fig. 28 of his account.²
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus stuhlmannii (Engl.) Engl. & Gehrm.
2. Pflanzenr., IV, 23C: 81 (1911) — protologue.
3. Alan Galloway — Amorphophallus stuhlmannii, alangallowaybotanicals.com.
4. Aroideana 19 (1996):P7 - 131
5. iNaturalist: Amorphophallus stuhlmannii
6. Das Pflanzenreich IV.23c (Araceae-Lasioideae), Fig. 28: 82 (1911)
Additional photos by Andrea L. Bianchi