AMORPHOPHALLUS HAYI
PROTOLOGUE: Amorphophallus hayi Hett., published in Blumea 39: 255 (1994).
A speciebus omnibus in rhizomate crasso longo horizontali c. 5 cm diam., spadice stipitato, appendice myosuroide horizontaliter curvata differt. Typus: Hetterscheid H. AM.278-T (L holo; spirit coll.), cult. Hort. Bot. Leiden ex North Vietnam, Lao Cai Province, Ban Khoang village, across the Sa Pa to Phong Tho road, on a small, seasonally inundated island in a creek bed, on granitic bedrock, in schistose alluvial soil, in very deepshade, alt. 1500 m (orig. coll. Goodwin 92/124).
DISTRIBUTION: China (SE. Yunnan) to N. Vietnam: Yunnan, Vietnam.
DISTRIBUTION NOTE: North Vietnam: Lao Cai.
SPECIES DESCRIPTION:
Rhizome horizontal, branching infrequently, to ca. 25 cm long and 5 cm in diam., brown and green, internodes 1–1.3 cm long, leafscars transversely oval, offset tubers long lasting, depressed, broadly attached, roots mainly developed from the ventral side. Leaf solitary or paired or simultaneous with inflorescence, the latter emerging from the petiole sheath; petiole ca. 40–60 cm long, ca. 1–1.5 cm in diam., turgid, smooth, moderately glossy, background color dirty greyish green but nearly totally hidden by large, oval, confluent, reddish brown spots; lamina 50–70 cm in diam., anterior segment less strongly developed than posterior ones; leaflets lanceolate, 8–32 cm long, 2.5–7 cm in diam., acuminate, margin crispate-undulate, upper side moderately glossy green, venation quite strongly impressed, lower side paler green.
INFLORESCENCE:
Inflorescence solitary or with leaf, long-peduncled; peduncle ca. 50 cm long, 1.5 cm in diam. at the base, 0.8 cm in diam. at the top, smooth, reddish brown to yellowish brown, densely covered with dark reddish brown, elongate-oval, often confluent spots; spathe ovate, erect, funnel-shaped, margin involute, upper third part horizontally spreading; lower part loosely convolute, base and limb not differentiated, 16–20 cm long, 12–15 cm in diam., top narrowly acute, outside base very pale purplish brown on a creamish background, with numerous, small and slightly larger, punctiform, rounded, partly confluent, dark purplish brown spots, upper part outside dirty cream with less numerous rounded spots but numerous tiny ones, to the margin flushed with grey, inside base dark maroon, upper part creamish with few tiny dark purple spots, to the margin flushed with dirty dark brownish green, base within with very shallow, interconnected ridges. Spadix shortly stipitate, longer than spathe, 20–28 cm long.
ECOLOGY:
Found on a small, seasonally inundated island in a creek bed, on granitic bedrock, in schistose alluvial soil, in very deepshade, alt. 1500 m
ETYMOLOGY:
Named in honor of Alistair Hay, Australian botanist and specialist in Araceae, whose taxonomic work substantially advanced the study of aroids in Asia and the western Pacific. The epithet hayi is the Latinized genitive of his surname, meaning “of Hay” or “Hay’s.
NOTES:
1. The stout rhizome of Amorphophallus hayi and the styleless, ovate ovaries with their very thin stigmas render this species unique in the genus. The only other known truly rhizomatous species hitherto known is Amorphophallus rhizomatosus Hett. From this, Amorphophallus hayi differs a.o. in the much stouter rhizome and a different leaf type.
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus hayi Hett.
2. Blumea 39: 255 (1994) — protologue.
3. Aroideana 19 (1996):P7 - 131
Additional photos by Sim Lav