AMORPHOPHALLUS PENDULUS
PROTOLOGUE: Amorphophallus pendulus Bogner & Mayo, published in Aroideana 8: 19 (1985).
Amorphophallus pendulus Bogner & Mayo, sp. nov. Appendice longa, tenui, pendula, basi staminodia ferenti a congeneribus diversa. Typus: Sarawak, J.A.R. Anderson s.n. (K, holotypus, spirit collection no. 7237).
DISTRIBUTION: Borneo (Brunei, Sarawak): Borneo.
DISTRIBUTION NOTE: iNaturalist: Kuching, Sabah, Sandakan, Sarawak.
SPECIES DESCRIPTION:
Tuber subglobose. Petiole 15-40 cm long, 0.3-0.5 cm in diam., spotted, the spots pale green, densely arranged, confluent and mostly obscuring the reddish background colour. Leaf blade compound, basically tripartite, each major segment further subdivided subpinnately, rhachis spotted like the petiole; leaflets decurrent, very narrowly elliptic, acuminate, 6-13 cm long, 1.5-3 cm broad, dark velvety green, somewhat glossy - the collector noted them as dark purplish or silverish in the wild, colours the plant tends to lose in cultivation; venation reticulate, middle vein strong, 7-10 lateral veins of the first order on each side, collecting vein 2-3 mm from the margin. Cataphylls up to 12 cm long, mostly 3, the first shortest at about 3 cm and the last the longest, spotted, soon drying and turning brown, when fresh with pale spots on a reddish background.²
INFLORESCENCE:
Peduncle 20-40 cm long, 0.4-0.8 cm in diam., spotted, background colour dark purple with circular pale green spots of different sizes. Spathe 15-18 cm long, the lowermost 5-7 cm convolute and forming a tube, the upper part 10-11 cm and forming a slightly hooded, fornicate lamina, outside dark to blackish-purple with circular pale green spots that are bigger and more densely arranged on the tube and sometimes confluent, inside dark to blackish-purple with small pale green spots near the margins, papillose at the base for about 1 cm. Spadix 27-42 cm long; female part 1.5-2 cm long, 0.6-1 cm in diam.; male part contiguous with the female, 2.4-4 cm long, 0.4-0.8 cm in diam., turning gradually into a long, slender, pendulous appendix; appendix 23-36 cm long, 0.4 cm in diam. at the base, 0.2-0.3 cm in diam. at the middle, pale yellow, the lower 2-4 cm covered with staminodes, these denser at the base and becoming scattered upwards, the remainder of the appendix with a rough, ridged surface. Ovary globose, about 1.8 mm in diam.; stigma sessile, 1.8-2 mm in diam., usually trilobed, rarely two- to four-lobed, the lobes conical and erect. Male flowers densely arranged, yellowish; stamens 0.8-1 mm long, 0.5-0.6 mm broad.²
ETYMOLOGY:
From Latin pendulus, “hanging” or “pendulous,” referring to the extraordinary long, whip-like spadix appendix, which bends downward and may reach around 60 cm in length. This pendulous appendix is one of the most conspicuous and distinctive features of the species.
NOTES:
1. Diagnosis: it is distinguished from its congeners by a long, thin, pendulous appendix that bears staminodes at its base.²
2. That staminodial base mattered beyond this one species. When Bogner and Mayo reduced the genus Thomsonia to Amorphophallus in the same paper, part of their case was that the appendix character Engler had used to keep the two apart broke down - and Amorphophallus pendulus, sparsely papillose at the appendix base where fertile stamens grade into papillae, was one of the two observations that broke it. The other was Amorphophallus kerrii, whose appendix runs from distinctly staminodial to quite smooth.²
3. The dark purplish or silvery cast of the leaflets, noted by the collector in the wild, fades in cultivation.²
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus pendulus Bogner & Mayo
2. Aroideana 8: 19 (1985) — protologue.
3. Alan Galloway — Amorphophallus pendulus, alangallowaybotanicals.com.