AMORPHOPHALLUS NAPALENSIS
PROTOLOGUE: Amorphophallus napalensis (Wall.) Bogner & Mayo, published in Aroideana 8: 19 (1985).
Amorphophallus napalensis (Wallich) Bogner & Mayo, comb. nov. Type: Nepal, in mountain forests, flowering in June, illustration published by Wallich, Pl. As. rar. 1: t. 99 (1830).
SYNONYMS:
HOMOTYPIC SYNONYMS: Thomsonia napalensis Wall. in Pl. Asiat. Rar. 1: 83 (1830)
HETEROTYPIC SYNONYMS: Allopythion hookeri Schott in Gen. Aroid.: t. 24 (1858) Arum grandiflorum Ham. ex Hook.f. in Fl. Brit. India 6: 518 (1893), pro syn. Pythonium wallichianum Schott in H.W.Schott & S.L.Endlicher, Melet. Bot.: 17 (1832) Thomsonia hookeri (Schott) Engl. in A.L.P.P.de Candolle & A.C.P.de Candolle, Monogr. Phan. 2: 307 (1879)
DISTRIBUTION: Nepal to Myanmar: Assam, Bangladesh, East Himalaya, Myanmar, Nepal.
DISTRIBUTION NOTE: Bhutan; Nepal; India: Sikkim, Assam, Meghalaya and Arunachal Pradesh.⁷.
SPECIES DESCRIPTION:
Tuber subglobose or depressed-globose, to ca. 15 cm in diam., ca. 12 cm high, pale to dark dirty brownish, producing seasonal offsets, these rhizomatous, gradually thickening to the top, to 10 cm long and 1.5 cm in diam. Leaf solitary; petiole to ca. 1 m long, ca. 3 cm in diam. at the base, smooth, background color pale green, with more or less large, irregular or elongate-oval dark green or blackish spots, sometimes accompanied by numerous smaller dark green spots; lamina highly dissected, to ca. 1.5 m in diam.; leaflets elliptic-oblong or elliptic-lanceolate or obovate, 8-20 cm long, 4-8 cm in diam., margin undulate, top long-acuminate, upper surface mid-green.⁴
INFLORESCENCE:
Inflorescence long-peduncled; peduncle as petiole, ca. 30-80 cm long; spathe elongate-triangular, 14-40 cm long, 6-14 cm in diam., spathe and limb not differentiated, top acute, outside and inside pale green, becoming yellowish green at male anthesis and then opening wider, base within sometimes with a pale purplish hue, with numerous, slightly distant, small, irregular or conic warts. Spadix sessile, shorter than spathe, 10-26 cm long, appendix with numerous, small, conical warts.⁴
ECOLOGY:
Found rarely in mountain forest.⁸ Flowering May-June; fruiting July-September.⁷
PROPAGATION:
We failed in our only attempt to root this species with cuttings taken in mid-August. Even with proper timing, this was among the most difficult species to root.
ETYMOLOGY:
From Napal, a historical Latinized spelling of Nepal, together with-ensis, “from” or “of,” literally meaning “from Nepal.” The spelling preserves older nineteenth-century geographical orthography rather than the modern English form Nepal. The species occurs across the Himalayan region in Nepal, Bhutan, Sikkim, and adjacent areas.
NOTES:
1. Amorphophallus napalensis is similar to Amorphophallus curvistylis, but the latter has a smooth appendix and bilabiate stigmas. This species is often found in cultivation and is usually imported from India in shipments of Amorphophallus bulbifer.⁴
2. Among the Indian species it is set apart by a verrucate appendix with short, prominent warts, a style bent apically towards the spadix-axis, and a four-lobed stigma.⁷
3. Type locality: mountain forest in Nepal, flowering in June. The name rests on a published illustration rather than on a herbarium specimen - Wallich's plate 99, drawn from the plants he described.²
STORY:
STORY TITLE: The genus that turned out to be a species
In 1830 Nathaniel Wallich published a plant he had received from the mountain forests of Nepal, where it flowered in June. He thought it strange enough to need a genus of its own, and named that genus Thomsonia for Anthony Todd Thomson, professor of materia medica at London University - taking care, in a footnote, to warn readers not to confuse it with Thompsonia, which belonged to the passionflowers. The plant itself he called Thomsonia napalensis, and had it painted: a great brown tuber like a loaf, three mottled stalks rising from it, one bearing a spathe cracked open on a spadix crusted with warts. That painting, plate 99, is the type of the name. There is no specimen behind it.
What set the genus apart was that crust. In Amorphophallus the appendix - the sterile club at the top of the spadix - was taken to be smooth; in Thomsonia it was densely tuberculate, covered in projections that are modified male flowers. Engler built his key on the difference in 1911, and for a century and a half the two genera stood on either side of it, with Thomsonia holding a single reliable species.
Then the character came apart. Engler himself had conceded that the appendix of Amorphophallus could be warty or wrinkled as well as smooth. A second Thomsonia described in 1976 turned out to have projections even more obviously staminodial. Collections of Amorphophallus kerrii from Thailand were found to run the whole way from distinctly staminodial to quite smooth, and Amorphophallus pendulus, a new species from Sarawak, proved sparsely papillose at the appendix base, where fertile stamens graded into papillae. A boundary that varies inside one species is not a boundary between genera. In 1985 Bogner, Mayo and Sivadasan folded Thomsonia into Amorphophallus, and Wallich's plant became Amorphophallus napalensis.
It has kept a quiet second life. Growers across the Himalayan range from Nepal and Bhutan into Sikkim, Assam, Meghalaya and Arunachal Pradesh know it as a hardy, handsome thing, and it turns up regularly in cultivation - usually not because anyone ordered it, but because it travels to Europe mixed into shipments of Amorphophallus bulbifer.
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus napalensis (Wall.) Bogner & Mayo
2. Aroideana 8: 19 (1985) — protologue.
3. Alan Galloway — Amorphophallus napalensis, alangallowaybotanicals.com.
4. Aroideana 19 (1996):P7 - 131
5. Propagation of Amorphophallus by Leaf Petiole Cuttings — Juniper Level Botanic Garden
6. iNaturalist: Amorphophallus napalensis
8. Plantae Asiaticae Rariores 1: 83, t. 99 (1830) - Thomsonia napalensis, the basionym
9. Das Pflanzenreich IV.23c (Araceae-Lasioideae), Fig. 22: 57 (1911)