AMORPHOPHALLUS SMITHSONIANUS

PROTOLOGUE: Amorphophallus smithsonianus Sivadasan, published in Willdenowia, Bd. 18, H. 2 (Feb. 22, 1989), pp. 441-443.

Amorphophallus smithsonianus Sivadasan, sp. nova. Typus: India, Kerala, Trivandrum District, near Attayar on the way to Agasthyamala peak from Bonacord, 590 m, 25.12.1985, Sivadasan CU 21547 (holo- K; iso- B, CAL, M, US). Amorphophallus hohenackeri, Amorphophallus mysorensi et Amorphophallus sylvatico affinis, a quibus imprimis spatha infundibulari, spadice sessili, appendice spadicis longiore, flexa vel dependente, stigmate echinato, folioliis erosis marginatis differt.

DISTRIBUTION: SW. India: India.

DISTRIBUTION NOTE: India: Kerala, in the Agasthyamala hills of the Western Ghats near Attayar, on the way to the peak from Bonacord - the only locality known.².

SPECIES DESCRIPTION:

Corms smooth and glossy-skinned, usually compressed globose or irregularly subglobose from growing in crevices, 3.0-4.5 cm across and 2.0-2.5 cm thick in the vegetative phase, about 4.5-9.0 cm across and 3.5-4.0 cm thick in the reproductive phase. Leaf solitary with 4-6 cataphylls; cataphylls 9.0-12.0 cm long, occasionally to 18.0 cm, and 2.5-3.0 cm broad, the tip acute with a stiff bifid-tipped projection, light pink from minute pinkish specks. Petiole 27-58 cm long, 1.1-1.9 cm across at the base and 0.6-0.9 cm at the tip, green with white specks and mottling, the base white and the upper portion green. Leaflets obovate to oblong, acuminate, green above and light green beneath, glossy, the venation closely pinnate with a submarginal vein present, the margin erose.²

INFLORESCENCE:

Corms in the reproductive phase carry 4-6 cataphylls, the innermost equalling or exceeding the peduncle. Peduncle 11.0-14.0 cm long and 0.6-0.9 cm across at the base, coloured as the petiole. Spathe funnel-shaped, broadly obovate with a rounded or obtuse, entire or notched apex, 4.0-5.5 cm long and 5.5-6.5 cm broad, convolute with the top widely open; outside light green or greenish yellow with minute purplish specks above; inside dark purplish with minute truncate projections over the basal third, and light yellowish green or creamy and smooth above. Spadix sessile, 21-30 cm long: a basal female portion 0.8-1.1 cm long, a neuter portion 0.4-0.7 cm long, a male portion 2-3 cm long, and a sterile appendix 17.5-25.5 cm long. Female flowers densely arranged; ovary about 1.5 mm high and 2 mm across, cream; style very short, 0.5-0.7 mm high; stigma about equalling the ovary in width and bearing 3-5 stout spines, light green becoming cream after anthesis. Neuter flowers in 1-5 rows, each obovoid or ellipsoid, dark purplish or sometimes light green to brownish, about 6 mm high and 4 mm across, shrinking and thinning with age. Male flowers loosely or densely arranged, each about 1 mm high and subrectangular in outline with rounded corners, about 1.5 mm long and 1 mm broad, cream or light greenish to yellowish green with a light purplish tinge at the top, or rarely wholly dark purplish, opening by apical confluent pores that look like slits on each theca. Appendix 17.5-25.5 cm long, about 0.9 cm across at the base and tapering to the tip, bent or hanging from the middle, dark purplish with a sometimes purplish green tip, becoming warted with age and turning light yellowish brown or cream, withering from the tip downwards; the base with irregular shallow lengthwise furrows and a few small spine-like projections. Fruits and seeds have not been collected.²

ECOLOGY:

Growing in humus on rocks and in rock crevices in evergreen forest, at about 590 m.²

PROPAGATION:

We were able to root this species at 43.5% in our only attempt with early September cuttings.

ETYMOLOGY:

Named for the Smithsonian Institution in Washington, D.C., reflecting the close historical connections between Indian aroid research and the Smithsonian’s Department of Botany. The Latinized adjective smithsonianus means “of or pertaining to the Smithsonian.” The species was described by M. Sivadasan in 1989 from southwestern India.

NOTES:

1. The appendix is the whole of the plant's height. At 17.5-25.5 cm it is four to five times the length of the spathe, and it bends over or hangs from the middle rather than standing erect.²

2. Three characters together separate it from everything else then known: the funnel-shaped spathe, the sessile spadix, and a stigma armed with 3-5 stout spines. The erose leaflet margins are a fourth.²

3. It is one of only four species known at the time to carry a band of neuter flowers between the female and male zones, the others being Amorphophallus hohenackeri, Amorphophallus mysorensis and Amorphophallus sylvaticus.²

4. Amorphophallus sylvaticus is the closest of those in the arrangement of its spadix, but its spathe is convolute and cylindric with an acute tip, its spadix is stalked, its neuter flowers are oblong and swollen on one side, its stigma is more or less three-lobed, and its appendix - though more than twice the length of the spathe - always stands erect.²

5. On the strength of this species the author merged the monotypic section Synantherias into section Rhaphiophallus.²

6. The type was gathered in December, at the start of the southern Indian summer, when a plant of this genus would rarely be found in leaf and in flower at once.²

REFERENCES:

1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus smithsonianus Sivadasan

2. Willdenowia, Bd. 18, H. 2 (Feb. 22, 1989), pp. 441-443 — protologue.

3. Alan Galloway — Amorphophallus smithsonianus, alangallowaybotanicals.com.

4. Aroideana 19 (1996):P7 - 131

5. Propagation of Amorphophallus by Leaf Petiole Cuttings — Juniper Level Botanic Garden