AMORPHOPHALLUS RICHARDSIAE

PROTOLOGUE: Amorphophallus richardsiae Ittenb., published in Willdenowia 27: 157 (1997).

Amorphophallus richardsiae Ittenb., sp. nova Differt ab Amorphophallo swynnertonii pollinibus striatis, appendici spathae longiore, ovario 2-3-loculato, stigmate 2-3-gibberoso et relatione partis pistillatae et staminatae inflorescentiae (0.35-0.4 ad 1). Holotypus: Zambia, Kalambo Falls, 15.11.1960, H.M. Richards 13579 (K!).

DISTRIBUTION: NE. Zambia: Zambia.

DISTRIBUTION NOTE: The borderland of Zambia and Tanzania, from Mbala to the Kalambo waterfalls. The type was gathered at Kalambo Falls in November 1960.².

SPECIES DESCRIPTION:

Tuber and leaf unknown. Cataphylls 2(?), the inner 2.3-13.5 x 2-6 cm, the outer 7 x 1.2 cm, broad-oval, creamy with a pink flush and brownish elongate-oval spots.²

INFLORESCENCE:

Inflorescence to 40 cm long, long-peduncled, appearing before the leaf; peduncle 12-15 cm long, greenish with numerous small confluent, elongate to oval, dark green to brown spots. Spathe erect, 16-24 cm long, separated by a distinct constriction into an asymmetrical oval to triangular tube and a wide, triangular to oval limb; tube 5-8 x 4-6 cm, outside brownish green at the base, higher up becoming green, veins brownish to bright purple and densely covered with round dark greenish and brownish spots; inside at the base purple, with strongly raised veins, these crowded with warts and flag-shaped emergences, so that the veins frequently appear as uneven or evenly high ridges; constriction inside with a 1-2 cm wide, greyish green waxy band; limb 10-17 cm long, upwards oblique, outside dirty green with violet veins, inside brown purple, margins undulate. Spadix sessile, 21-27 cm long, equal to or up to 6 cm longer than the spathe; pistillate zone cylindrical, 1.2-2.5 x 1.2-1.5 cm, flowers congested; staminate zone cylindrical to slightly ovoid, 3.2-6 x 1-1.5 cm, flowers congested; appendix 14-20 cm long, elongate-conical to cylindrical, slightly constricted and grooved above the staminate zone, purple; staminodes absent; no sterile zone between the pistillate and staminate zones; ratio of pistillate to staminate zone length 0.35-0.4: 1. Pistillate flowers 2.5-3.5 mm long; ovaries more or less ovoid, 2-2.5 x 1.5-2 mm, 2-3-locular, dark yellowish; stigma sessile, shallowly 2-3-lobed, roundish flat in lateral section, circular to oval in cross section, 1-2 x 1-1.5 mm, brown to black. Staminate flowers 1-1.5 mm long; anthers cubic, free, 0.5 x 0.7 mm, bright brown; filaments 0.7-1 x 0.7-1 mm, free; connective slightly grooved and with dark strips; pores circular, one apical pore per theca. Infructescence unknown. Pollen inaperturate, exine striate.²

DISTRIBUTION MAPS:

ETYMOLOGY:

Named for H.M. Richards, who made rich plant collections in south-eastern Africa and who gathered the type at Kalambo Falls.²

NOTES:

1. Diagnosis: it differs from Amorphophallus swynnertonii in striate pollen, an appendix longer than the spathe, a 2-3-locular ovary, a 2-3-humped stigma, and the ratio of pistillate to staminate zone length, 0.35-0.4 to 1.²

2. Amorphophallus richardsiae is most similar to Amorphophallus swynnertonii, which is not in fact conspecific with Amorphophallus abyssinicus.²

3. Neither the tuber nor the leaf has ever been described - the species is known only from flowering material and from plants that later flowered in cultivation at Kew.²

REFERENCES:

1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus richardsiae Ittenb.

2. Willdenowia 27: 157 (1997) — protologue.

3. Alan Galloway — Amorphophallus richardsiae, alangallowaybotanicals.com.