AMORPHOPHALLUS TENUISPADIX

PROTOLOGUE: Amorphophallus tenuispadix Hett., published in Blumea 39: 277 (1994).

Amorphophallus tenuispadix Hett., spec. nov. Ab Amorphophallo longituberoso (Engl.) Engl. & Gehrm. in tubere globoso, antheris poribus apicalibus, ovario uniloculari differt. - Typus: Rabil 291 (K holo; iso BK, K), Thailand, Kao Chom Lem, Ampo Kao Kao, on foot of hill, 2-viii-1929.

DISTRIBUTION: S. Thailand: Thailand.

DISTRIBUTION NOTE: Thailand: Kao Chom Lem in Ampo Kao Kao, where the type was gathered in August 1929, and Kao Chem near Thung Song.².

SPECIES DESCRIPTION:

A small species. Tuber globose, 2-3 cm across and 1.8-2.5 cm deep. Leaf solitary; petiole smooth and slender, 22-32 cm long and 0.7 cm across at the base. Lamina highly dissected, 36-45 cm across, the rachises narrowly winged only in the most distal branches; the main segments subdichotomous, the central one unbranched in smaller leaves; leaflets lanceolate, the base decurrent or nearly so, acute, the top long acuminate, 5-12 cm long and 1.5-3 cm across.²

INFLORESCENCE:

Inflorescence solitary and long-peduncled; cataphylls up to 15 cm long; peduncle as the petiole, 11-29 cm long and 0.5 cm across at the base. Spathe elliptic to lanceolate, the base shortly convolute, the top acute and shortly apiculate, the base within bearing many loosely arranged hemispheric or slightly elongate warts, 5-13 cm long and 2-3.5 cm across, white. Spadix sessile, equalling the spathe or slightly longer, rarely shorter, 5.5-12 cm long; female zone cylindric, 1-2.5 cm long and 0.4-0.5 cm across, the flowers more or less distant; male zone cylindric, 2.5-5 cm long and 0.4-0.6 cm across, the flowers congested; appendix fusiform with an obtuse apex, smooth, 1.5-4 cm long and 0.5-0.9 cm across. Ovaries shortly stalked, depressed, circular in cross section, 1.5-2 mm across and about 1 mm high, unilocular, the stalk 0.5 mm long; style more or less conic, 1.2 mm long and 0.8 mm across; stigma large, disc-shaped with a shallow central depression, circular in cross section, 1.3-1.5 mm across and 0.3 mm high. Male flowers of 2-4 stamens; stamens 1.5 mm long; filaments 0.5 mm long, connate in the basal half; anthers truncate, 1.4 by 0.8 mm and 1 mm long, the pores apical and elongate. Pollen irregularly striate.²

ECOLOGY:

Gathered at the foot of a hill, and on rock.²

PROPAGATION:

In mid-July, we achieved 100% rooting, but that had dropped to 75% for cuttings taken in early August. With proper timing, this was among the species that rooted at the highest percentages in the trials.

ETYMOLOGY:

From Latin tenuis, “slender,” and spadix: the spadix of this species is only 4-6 mm across, and the whole plant is small - the tuber is 2-3 cm wide.²

NOTES:

1. Amorphophallus tenuispadix closely resembles Amorphophallus albispathus, described in the same paper, but differs in a globose tuber, apical anther pores and a one-chambered ovary. It differs from Amorphophallus longituberosus in the same characters.²

2. A gathering of this species had earlier been cited by Gagnepain under the name Pseudodracontium kerrii, which he published without the Latin diagnosis then required and which is therefore not validly published. He appears to have overlooked the smooth appendix.²

3. Pseudodracontium is no longer recognised as a separate genus; its species are now placed in Amorphophallus.²

REFERENCES:

1. Plants of the World Online, Royal Botanic Gardens, Kew — Amorphophallus tenuispadix Hett.

2. Blumea 39: 277 (1994) — protologue.

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

4. Propagation of Amorphophallus by Leaf Petiole Cuttings — Juniper Level Botanic Garden