AMORPHOPHALLUS MARGARITIFER
PROTOLOGUE: Amorphophallus margaritifer (Roxb.) Kunth, published in Enum. Pl. 3: 34 (1841). The protologue is reproduced below.
SYNONYMS:
HOMOTYPIC SYNONYMS: Arum margaritiferum Roxb. in Fl. Ind., ed. 1832. 3: 512 (1832) Plesmonium margaritiferum (Roxb.) Schott in Syn. Aroid.: 34 (1856)
HETEROTYPIC SYNONYMS: Plesmonium dubium Schott in Prodr. Syst. Aroid.: 125 (1860) Plesmonium margaritiferum f. minor Engl. in Pflanzenr., IV, 23C: 51 (1911)
DISTRIBUTION: India to Myanmar: Assam, Bangladesh, East Himalaya, India, Myanmar.
DISTRIBUTION NOTE: India: recorded from Maharashtra, Madhya Pradesh, Uttar Pradesh, Rajasthan, Bihar, West Bengal, Sikkim and Assam⁶.
SPECIES DESCRIPTION:
Tubers more or less sub-globose to depressed globose, 2.5-5.0 cm diam. and 1.8-3.5 cm thick in vegetative phase, 7-13 cm diam. and 5.0-6.5 cm thick in reproductive phase, seasonally producing numerous small globose to fusiform offsets, varying from 7-11 per tuber, each 5-7 mm diam. and 8-14 mm long; skin pale brown to yellowish brown. Petiole smooth, 24-84 cm long, 1.0-3.3 cm diam. at base; green with numerous narrowly elongated black-margined pale green stripes, with small spots between, petiole paler towards the tip, dark green to blackish green at the extreme base. Lamina 32-76 cm diam., the primary rachises smooth and coloured as for petiole; leaflets linear to lanceolate, 8-24 cm long, 1.1-3.5 cm broad, decurrent at base, upper surface green, paler below.⁶
INFLORESCENCE:
Peduncle smooth, 50-70 cm long, 2-4 cm diam., colour same as that of the petiole. Spathe broader than long, broadly ovate or broadly triangular, 11.0-17.5 cm long, 13-20 cm broad, tip acute, not differentiated into basal tube and upper limb; pale greenish outside, pale purplish within, dark purplish, prominently verrucate at base within. Spadix as long as or slightly longer than the spathe, 14-20 cm long, lacking a sterile appendix; stipe 6-11 mm, greenish; female zone 1.1-2.8 cm long, 9-18 mm diam.; staminodial zone 2.0-3.5 cm long; male zone elongate-conoidal, 6-9 cm long, 1.0-1.5 cm diam. at base. Female flowers each 5-6 mm high; ovary pale green, slightly broader than stigma, 2.5-3.0 mm long, c. 2.5 mm diam., 2-locular; style very short, 0.5-1.0 mm long; stigma yellowish, capitate, distinctly 2-lobed, rarely 3-lobed, surface verrucate. Neuter flowers loosely arranged, large, elongate-obovoid, 7-9 mm long, 4-5 mm diam. at top, cream, tip obtuse or subtruncate. Male flowers each 2-3 mm high, 1.5-2.0 mm broad, pale brownish yellow. Fruit subglobose, red at maturity, c. 8 mm long.⁶
PROPAGATION:
We failed to root this species in our only attempt when cuttings were taken in early September.
ETYMOLOGY:
From Latin margaritifer, "pearl-bearing": Roxburgh's Arum margaritiferum was named for the large, pearl-like neuter flowers — Kunth's diagnosis reads "nectariis margaritae magnae similibus", nectaries like great pearls.²
NOTES:
1. Amorphophallus margaritifer resembles Amorphophallus longiconnectivus in its general appearance of greenish spathe that is not differentiated into tube and limb, and the nature of the spadix, but differs in having large elongate-obovoid, cream-coloured neuter flowers — the "pearls" of the name — and in completely lacking a spadix-appendix.⁶
2. The lectotype of the species is Wight's 1844 plate in the Icones Plantarum Indiae Orientalis, drawn from Roxburgh's Arum margaritiferum.⁶ Roxburgh knew the plant from Bengal, and Kunth transferred it to Amorphophallus in 1841 — on the same page of the Enumeratio on which he treated Amorphophallus lyratus.²
STORY:
STORY TITLE: The pearl-bearer
Every so often a botanical name is simply a description of something beautiful. When William Roxburgh examined this aroid from Bengal, what struck him were the sterile flowers between the male and female zones: large, cream-coloured, glossy globes, packed in rows around the spadix like strung beads. He called the plant Arum margaritiferum — the pearl-bearing arum — and when Kunth moved it to Amorphophallus in 1841 his Latin kept the image: nectaries like great pearls.
The pearls turn out to be the species' signature in more ways than one. Amorphophallus margaritifer is one of the few members of the genus with no appendix at all — the spadix simply ends in the male zone — so the rows of pearl-like neuter flowers, up to nine millimetres long, are the most theatrical thing it owns. Its closest relative, Amorphophallus longiconnectivus, shows the beginnings of the same reduction: sometimes an appendix, sometimes none, as if the two species were caught mid-experiment.
The species has one more distinction: it may be the only aroid whose type specimen is an engraving. Roxburgh's original material did not survive as the name-bearer; instead, the lectotype is the plate Robert Wight published in his Icones Plantarum Indiae Orientalis in 1844 — a picture of the pearl-bearer, pearls and all, drawn for Roxburgh and now standing in law for the species itself. From Assam and Bengal west to Rajasthan, the plant remains widespread across northern India, wearing a name that is less taxonomy than compliment.
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus margaritifer (Roxb.) Kunth
2. Enum. Pl. 3: 34 (1841) — protologue.
3. Alan Galloway — Amorphophallus margaritifer, alangallowaybotanicals.com.
4. Propagation of Amorphophallus by Leaf Petiole Cuttings — Juniper Level Botanic Garden
5. iNaturalist: Amorphophallus margaritifer
7. Flora Indica; or descriptions of Indian plants, ed. 1832, 3: 512 (Arum margaritiferum)
8. Icones Plantarum Indiae Orientalis 3: t. 795 (1844) - the lectotype plate