AMORPHOPHALLUS MACROPHYLLUS
PROTOLOGUE: Amorphophallus macrophyllus (Gagnep. ex Serebryanyi) Hett. & Claudel, published in Aroideana 35: 43 (2012).
Pseudodracontium macrophyllum Gagnep. ex Serebryanyi, spec. nov. Tuber depresso-globosum. Cataphylla 4 vel 5, persistentia. Pedunculus petiolo duplo longior, inflorescentia praecox. Appendix muricata. — Typus: Kerr 12866 (K holo), Thailand, Wang Kanai, Kanchanaburi Prov., 200 m alt., in crevices of limestone rocks, 15 May 1927.
SYNONYMS:
HOMOTYPIC SYNONYMS: Pseudodracontium macrophyllum Gagnep. ex Serebryanyi in Blumea 40: 232 (1995)
DISTRIBUTION: Thailand, SW. Vietnam: Thailand, Vietnam.
DISTRIBUTION NOTE: Thailand: Kanchanaburi Province (Wang Kanai, Sai Yok) and Ratchaburi (Khao Talu); Vietnam: the south, at the Xuen Moc Reserve in the east of the former Dong Nai Province — the same reserve that yielded Amorphophallus kuznetsovii and Amorphophallus lanceolatus.⁴.
SPECIES DESCRIPTION:
Tuber depressed-globose with a few irregular vertical and subhorizontal branches, c. 7 cm tall, to c. 10 cm diam., pale yellowish brown. Cataphylls 4 or 5, persistent, completely convolute, shortly apiculate at the apex, respectively 2 cm, 4-4.5 cm, 7.5 cm, and 9.5 cm long, pale whitish green with darker brown veins and some small, blackish green spots. Petiole 8.5-15 cm long, 0.8-1 cm diam. at the base, moderately glossy dark olive green with numerous narrow white stripes and a few black narrow-elliptic spots; anterior main segment always undivided, thick, coriaceous, dark green; posterior main segments consisting of three 'leaflets', these 18-25 × 10 cm.⁴
INFLORESCENCE:
Inflorescence emerging before leaf or rarely simultaneously; peduncle at least twice as long as the petiole, 17-49 cm long, to 1.6 cm diam. at the base, angulate, colour pattern like petiole but paler, ground colour darkening towards the top; spathe 8.8-13 cm long, to 11 cm diam., base convolute, top acute to shortly-apiculate, fleshy, outside pale yellowish green with pale green hue near the base and a few punctiform whitish spots, inside similar but without spots, base within with numerous punctiform warts arranged on transversely elongate shallow elevations. Spadix 6.7-10.8 cm long, sessile; female zone slightly conic, 1-1.9 cm long, 1.4-1.7 cm diam. at the base, flowers congested, 6 per spiral, slightly distant in the upper part; male zone more or less fusiform to obconic, 2.9-4.5 cm long, 1.7-2.2 cm diam. at the middle, flowers distant; appendix elongate-conic to elongate triangular, stipitate (stipe to 0.4-1 cm long), 3-4.5 cm long, 1.2-1.6 cm diam. at the base, white, muricate, with numerous distinct, more or less parallel, longitudinal grooves and ridges, stipe of appendix sometimes entirely covered by flat scars of reduced male flowers. Male flowers consisting of 3-6 stamens (mostly 5), ivory-white; filaments mostly free but in the lower flowers irregularly to entirely connate, forming a column; anthers free but in the lower flowers also irregularly to entirely connate in one flower forming a disciform fertile synandrium; pores elongate, oblique, in partly synandrious flowers often fused to arcuate pores, in completely synandrious flowers all fused into one pore around the entire circumference of the synandrium. Infructescence: mature berry pale red, nearly quadrangular, c. 0.6 cm long, 4 mm thick, one-seeded; seed white, oblong-ovoid, laterally compressed, 4 × 2 mm. Seedling leafblades consisting of 2 leaflets.⁴
ECOLOGY:
Found in crevices of limestone rocks at the type locality; in southern Vietnam recorded from seashore dry dipterocarp forest on carbonate sands; altitude: c. 200 m⁴
ETYMOLOGY:
The epithet macrophyllum, "large-leaved", was Gagnepain's manuscript name from the Flore Générale de l'Indo-Chine; his 1942 publication carried no Latin diagnosis and was invalid, and Serebryanyi validated the name in 1995.⁴
NOTES:
1. Pseudodracontium macrophyllum shows some characters unique for the genus: the depressed-globose irregularly branched tuber, the inflorescence emerging before the leaf and at least two times longer than the petiole, the anthers opening by rounded pores and the remarkable muricate appendix. The species was published without a Latin diagnosis by Gagnepain and was therefore validly published only in the 1995 revision.⁴
2. When molecular and morphological evidence showed the genus Pseudodracontium to be nested within Amorphophallus, Hetterscheid and Claudel transferred the species as Amorphophallus macrophyllus.²
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus macrophyllus (Gagnep. ex Serebryanyi) Hett. & Claudel
2. Aroideana 35: 43 (2012) — protologue.
3. Alan Galloway — Amorphophallus macrophyllus, alangallowaybotanicals.com.
4. A taxonomic revision of Pseudodracontium (Araceae). Blumea 40(1): 217-235 (1995)