AMORPHOPHALLUS LONGITUBEROSUS
PROTOLOGUE: Amorphophallus longituberosus (Engl.) Engl. & Gehrm., published in Pflanzenr., IV, 23C: 73 (1911). The protologue is reproduced below.
SYNONYMS:
HOMOTYPIC SYNONYMS: Hydrosme longituberosa Engl. in Bot. Tidsskr. 24: 273 (1902)
HETEROTYPIC SYNONYMS: Amorphophallus viridis Ridl. in J. Straits Branch Roy. Asiat. Soc. 61: 63 (1912)
DISTRIBUTION: Bangladesh to N. Pen. Malaysia: Bangladesh, Peninsular Malaysia, Thailand.
DISTRIBUTION NOTE: Thailand and northern Peninsular Malaysia. The basionym type was collected on Koh Kahdat, Thailand, by the Danish Siam Expedition of 1899-1900 (J. Schmidt 541)⁶; as Amorphophallus viridis, the species was described from Pulau Tengah in the Adang group, Malaysia.⁷.
SPECIES DESCRIPTION:
Tuber elongate, usually unbranched at maturity, off-white, turning grey or blackish brown at exposure, to 25 cm long, top-part to 7.5 cm in diam. Leaf solitary; petiole 10-60 cm, 0.5-2 cm in diam. (base), smooth, with a whitish waxy cover, ground color dirty pale grey, pale pinkish or pale green to various extents covered with dark grey or dark blackish green oval spots and/or ditto stripes, the latter often running the entire length of the petiole; lamina highly dissected, diameter to 120 cm; leaflets elliptic or lanceolate, 6-17 cm long, 2-5 cm in diam., shortly or long-acuminate, base decurrent, slightly succulent, main veins impressed, upper side green, lower side pale green.⁴
INFLORESCENCE:
Inflorescence long-peduncled; peduncle as petiole, 10-76 cm long, to 1.5 cm in diam. (base); spathe erect, elliptic to elongate triangular, acute, top fornicate or nearly so, base convolute, widening at male anthesis, 4.0-18.5 cm long, 2.0-11.5 cm in diam., base inside nearly smooth, with few, scattered, shallow warts or densely covered with tiny, punctiform warts or moderately to densely covered with fleshy, elongate, variously branched warts, outside pale grey with several rounded or broad, elongate, dark grey spots/stripes and small white dots or uniformly green or greenish white with a few small white spots and/or some maroon streaks and a reddish or violet margin, inside entirely dirty greyish white or pale green, sometimes the upper part flushed with violet, with a darker green or pale to dark maroon base, margin sometimes flushed with greyish purple. Spadix sessile, slightly or distinctly shorter than spathe, 3.0-15.5 cm long, giving off a pleasant, anise-like scent.⁴
ECOLOGY:
Found in shaded or open places in evergreen or deciduous forests, in dry dipterocarp or dipterocarp-oak forests, in scree, on sandy or rocky poor ground, on limestone or shaley, granite bedrock; altitude: 0-600 m⁴
PROPAGATION:
We were never able to obtain higher than 22.2% rooting with this species with cuttings taken in mid-July. All cuttings taken later in the season failed to root. Even with proper timing, this was among the most difficult species to root.
ETYMOLOGY:
From Latin longus, “long,” and tuberosus, “tuberous,” referring to the species’ characteristically long, narrow underground tuber, which may reach about 25 cm in length. The tuber shape is sufficiently distinctive to form part of the species’ separation from many superficially similar Amorphophallus.
NOTES:
1. Amorphophallus longituberosus mostly resembles Amorphophallus coudercii but differs markedly in having a sterile appendix. The two share the tuber shape, leaf shape, anise scent, the shape of the male flowers and the high number of locules — in Amorphophallus coudercii an appendix is simply not differentiated from the male zone.⁴
2. The species began as Hydrosme longituberosa, described by Engler in 1902 from material of the Danish Siam Expedition in Johannes Schmidt's Flora of Koh Chang⁶; Engler and Gehrmann transferred it to Amorphophallus in 1911. Ridley's Amorphophallus viridis, described in 1912 from the islands off the Malay Peninsula, proved to be the same species.⁷
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus longituberosus (Engl.) Engl. & Gehrm.
2. Pflanzenr., IV, 23C: 73 (1911) — protologue.
3. Alan Galloway — Amorphophallus longituberosus, alangallowaybotanicals.com.
4. Aroideana 19 (1996):P7 - 131
5. Propagation of Amorphophallus by Leaf Petiole Cuttings — Juniper Level Botanic Garden
8. Das Pflanzenreich IV.23c (Araceae-Lasioideae), Fig. 26: 74 (1911)