AMORPHOPHALLUS ROSTRATUS
PROTOLOGUE: Amorphophallus rostratus Hett., published in Blumea 39: 273 (1994).
Amorphophallus rostratus Hett., spec. nov. A Amorphophallus variabili Blume in stigmate rostrato, basi spathae cristis longitudinalibus prominente verrucatis differt. - Typus: Loher 2433 (K holo), Philippines, Central Luzon, Montalban, v-1896.
DISTRIBUTION: Philippines: Philippines.
DISTRIBUTION NOTE: Philippines: Luzon - Montalban, Central Luzon, where both known gatherings were made by Loher.².
SPECIES DESCRIPTION:
Tuber unknown. Leaf solitary; petiole c. 30 cm long (or more?), c. 1 cm in diam., smooth, with scattered elliptic pale spots and many short, dark lines; lamina c. 50 cm in diam. (or more?), rhachises narrowly winged all over; leaflets numerous, small, lanceolate, 3-7 cm long, 0.5-2 cm in diam., long acuminate.²
INFLORESCENCE:
Spathe elongate triangular, base strongly convolute, 20-25 cm long, 9-12 cm in diam., acute, base within darker than the limb and with numerous large, irregular warts aligned into vertical ridges. Spadix sessile, longer than spathe, 35-40 cm long; female zone cylindric or slightly conic, 4-5 cm long, c. 1.5 cm in diam., flowers more or less distant; male zone cylindric, 4-5 cm long, 1-1.5 cm in diam., flowers congested; appendix elongate conic, 27-30 cm long, c. 1.5 cm in diam., base with some scattered, shallowly conic staminodes. Ovaries ovate, circular in cross section, c. 2 mm high, c. 1.5 mm in diam., unilocular; style conic, 0.8 mm long, c. 0.5 mm in diam. at the base and c. 0.3 mm in diam. at the top; stigma large, 1-2 mm high, 0.7-1 mm in diam. at the base, lobate, the lobes one to many, one lobe extremely long and conical, up to 1.5 mm, the others shallow, surface rugulose. Male flowers consisting of 1-3 stamens; stamens c. 1.5 mm long; anthers sessile, 1-2 mm in diam., truncate, pores apical, elongate. Pollen psilate.²
ETYMOLOGY:
From Latin rostratus, “beaked”: one lobe of the stigma is drawn out into a long conical beak up to 1.5 mm long, while the others stay shallow. It is the character the diagnosis leads with.²
NOTES:
1. Diagnosis: it differs from Amorphophallus variabilis in the beaked stigma and in the spathe base, which carries prominent warty longitudinal ridges.²
2. Amorphophallus rostratus resembles Amorphophallus variabilis of Java, and that resemblance may explain the repeated reports of the Javan species from the Philippines. The beaked stigma and the strongly ridged spathe base separate them.²
3. The tuber has never been described, and the species is known only from two nineteenth-century Loher gatherings from the same place.²
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus rostratus Hett.
2. Blumea 39: 273 (1994) — protologue.
3. Alan Galloway — Amorphophallus rostratus, alangallowaybotanicals.com.