AMORPHOPHALLUS NICOLSONIANUS
PROTOLOGUE: Amorphophallus nicolsonianus Sivadasan, published in Pl. Syst. Evol. 153: 165 (1986).
Amorphophallus nicolsonianus Sivadasan, species nova Species habitu vegetativo cum Amorphophallo longituberoso (Engl.) Engl. & Gehrmann, specie Siamae, optime congruens, sed differt forma spatha, pistillo uniloculari et stigmate subdiscoideo inaequalimarginato. Speciei Amorphophallus hildebrandtii (Engl.) Engl. & Gehrmann primo aspectu maxime similis, a qua differt forma minore et cormis cylindricis. Type: Kerala State, Palghat Dist., Silent Valley Dam Site, alt. ca. 1000 m, 3 January 1983, Sivadasan CU 21516-A (holotype K). Isotypes: ibid., Sivadasan CU 21516-B (K), CU 21516-C and CU 21516-D (US), CU 21516-E (CAL), CU 21516-F (M).
DISTRIBUTION: India (Kerala): India.
DISTRIBUTION NOTE: India: Kerala - Palakkad District (Silent Valley, including the dam site at ca. 1000 m, Panthanthode, Valiaparathode at ca. 1350 m and Walghat at ca. 1700 m, and the Manthampotty forest near Mukkali) and Wayanad District (Periya, Thariyode and Meppadi).² Later collecting added Thiruvananthapuram District (Bonaccord), Kozhikode District (Thenpara forest) and Kannur District (Kannavam forest).³.
SPECIES DESCRIPTION:
Corms of the individuals with leaves (sterile) are usually more or less obconical to napiform or subcylindrical, to ca. 6 cm long and 4 cm diam., and those of the individuals with inflorescences (fertile) are usually cylindric, 13-18 cm long and 1.5-4.5(5.5) cm diam. Branched corms are also sometimes seen and this branching is presumed to be due to the interference of roots of neighbouring trees or stones etc. in the path of its growth. The skin is smooth, white to cream-coloured. Cataphylls usually 6-7, of varying lengths ranging from 1-24 cm long and about 1.5 cm broad, lorate, tip rounded, minutely apiculate. Petiole cylindric, smooth, 30-56.5(60) cm long and 0.9-1.5(2) cm diam., green with light green mottles and small dark purplish spots, basal portion of the petiole just above the corm white; the rachides smooth, terete, colour same as that of the petiole and without decurrent leaflet bases, 20-26 cm long and 0.4-0.7 cm diam. Petiole and rachides very turgid, breaking when bent without becoming crushed. Leaflets, except the terminal ones, with distinct petiolules or sometimes sessile; lamina ovate acuminate to oblong acuminate, base round and usually unequal; smaller leaflets ca. 6-7.5 cm long and 3-3.5 cm broad, bigger ones 13-18.5 cm long and 4.5-5.5 cm broad, upper surface dark green and glossy, lower surface light green; margin entire, undulate; venation pinnately reticulate, primary veins depressed above and prominent below; a submarginal vein formed by the union of the primary veins present.²
INFLORESCENCE:
Peduncle cylindric, smooth, 20-32 cm long and 0.4-0.6 cm diam., colour same as that of the petiole but slightly paler; cataphylls 6-7 of varying lengths to 18 cm and 1.3 cm broad. Spathe ovate lanceolate, acuminate, 10-11.5 cm long and about 3 cm broad, basally convolute for 2-4 cm, remainder flattened, erect, usually the two halves of the erect portion longitudinally reflexed at the middle at maturity; greenish brown to greenish purple with light green mottling and dark purple spots outside, and greenish yellow and smooth within, sometimes very light pinkish green tinged and with purple spots at the base within; the margin of the spathe reflexed at maturity; older spathes light creamy pink with light purple blotches and dark purple spots. Spadix sessile, 9-12 cm long, usually longer than the spathe, rarely shorter; basal 1-1.75 cm pistillate, middle 2-2.7 cm staminate and the rest 6-7 cm produced into a sterile appendix. Pistillate flowers green, loosely or densely subspiralled. Ovary subglobose, ca. 2 mm high, 2.5 mm diam., unilocular with a single basal anatropous ovule; style very short, thick, ca. 0.5 mm long; stigma capitate, more or less discoid with an uneven margin, 2.2 mm diam., notched at one point, green in colour and become brownish after anthesis. Staminate flowers cream or light pinkish cream coloured, densely arranged, each more or less rectangular in outline with round edges, sessile, 1.5 mm high, 1.5 mm thick and 1.75 mm broad, inconspicuously 2-lobed; dehiscence by narrow apical cleft. Appendix sessile, terete, tapering to the tip, yellowish green in colour, spinescent or with irregular-shaped vestiges of staminate flowers and irregular longitudinal furrows at the base, becoming completely corrugated and creamy or light yellowish on aging. Fruit an ellipsoidal, one-seeded, dark red-coloured berry, 1-1.3 cm long and 0.6-0.8 cm diam.; seeds ellipsoid to 1.1 cm long and 0.7 cm diam.²
ECOLOGY:
Found in semi-evergreen and evergreen forest; altitude: ca. 1000-1700 m²
ETYMOLOGY:
Named in honor of Dan Henry Nicolson (1933-2016) of the Department of Botany at the Smithsonian Institution in Washington, D.C., for his contributions to the study of aroids; he was one of the three botanists who confirmed for Sivadasan that the plant was undescribed.²
NOTES:
1. Amorphophallus nicolsonianus was the only Indian species of the genus known with cylindrical or napiform corms; every other species of the region has a globose or depressed-globose corm. Branched corms turn up occasionally, which is thought to happen where the roots of neighbouring trees, or stones, stand in the way as the corm grows.²
2. In vegetative habit it agrees closely with Amorphophallus longituberosus of Thailand, but that species differs in the shape of its spathe, an incompletely three- to four-locular pistil, and a clearly trilobed stigma on a distinct style. At first glance it is most similar to Amorphophallus hildebrandtii of Madagascar, from which it differs in its smaller size and cylindrical corms - Amorphophallus hildebrandtii has a petiole up to 2 m long, a spathe up to 90 cm long and 20-25 cm broad, and a depressed globose corm. Amorphophallus variabilis is also somewhat similar, but has a depressed globular corm and a multilocular ovary.²
3. The other species of the region flower just before and just after the first rains of the monsoon and are normally seen in inflorescence between April and June. Amorphophallus nicolsonianus instead flowers from December to February, in the middle of the summer, and one fertile plant has been collected as late as the third week of October. No other Amorphophallus of the region is known to flower in that window.²
4. Among the Indian species it is further set apart by a turgid, brittle petiole and peduncle, and by the two halves of the spathe limb reflexing longitudinally at maturity.³
5. Within Amorphophallus section Conophallus it is one of four species endemic to India, alongside Amorphophallus bognerianus, Amorphophallus carnosus and Amorphophallus oncophyllus. All four are considered endangered, and the section reaches its greatest diversity in Kerala, in the Western Ghats.³
STORY:
STORY TITLE: The species that flowers in the wrong month
In June 1977, working through the Araceae of South India, M. Sivadasan collected something in the Silent Valley that matched nothing in Engler's monograph or in anything published since. What he had was a leaf and an infructescence - no flower. Without an inflorescence there was nothing to describe.
So he went back. Every year, through April, May and June, he searched the same forest, because April to June is when Amorphophallus flowers in that part of Kerala: the inflorescences come up just before and just after the first rains of the monsoon, the leaves follow, and by November it is over. Year after year he found leaves, and no flowers.
The searches had been timed perfectly for every Amorphophallus of the region except this one. In January 1983 - midsummer in Kerala, months outside the flowering season, and Sivadasan happened to be in the valley - he found the plant in bloom. Some individuals carried leaves, some carried inflorescences, and the species could finally be described. It flowers from December to February, and no other Amorphophallus of the region is known to do so; a fertile plant has since turned up as late as the third week of October.
He named it for Dan Henry Nicolson of the Smithsonian Institution, one of the three aroid specialists - with Josef Bogner and Simon Mayo - who confirmed that the plant was new. It is still known only from a handful of forests in Kerala, and the six years it spent hiding were not a matter of rarity or remoteness. It was simply keeping a different calendar.
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus nicolsonianus Sivadasan
2. Pl. Syst. Evol. 153: 165 (1986) — protologue.