SCINDAPSUS KINABALUENSIS

PROTOLOGUE: Scindapsus kinabaluensis , published in Willdenowia 45: 410 (2015).

Scindapsus kinabaluensis (Furtado) Kartini & P.C.Boyce, comb. nov. Basionym: Rhaphidophora kinabaluensis Furtado, Gardens' Bulletin, Straits Settlements 8: 152 (1935). Type: Malaysian Borneo, Sabah, Kinabalu, Tenompok, 26 March 1932, C. X. Furtado comm. J. Clemens & M. S. Clemens sub no. 26875 (holotype SING; isotypes BM, K).

SYNONYMS:

HOMOTYPIC SYNONYMS: Rhaphidophora kinabaluensis Furtado

DISTRIBUTION: Borneo (Sabah): Borneo, Sabah.

SPECIES DESCRIPTION:

Medium-sized homeophyllous low climber or semi-terrestrial scandent shrub; stems smooth, terete or nearly so, internodes 2.5–5 × c. 1 cm, medium semi-glossy green with older portions becoming brown and slightly corky, later cracking and fissuring; roots sparse, stem bases with ramifying hypogeal roots, distal nodes of stems each producing a solitary thick fleshy feeding root, these often supporting scandent growth through adjacent low scrub; leaves rather dispersed along stems, becoming clustered (5–15 leaves together) at shoot tips prior to a flowering event; petiole (10–)21–23 cm long, shorter than or equalling blade, smooth, dark green, geniculate apically and basally, geniculi initially greenish brown, later becoming pale brown and corky; sheath broad, well developed, mostly extending to c. ¼ way along petiole, to c. ½ on leaf subtending an inflorescence; c. 6 mm wide, marcescent, persisting as tattered fibres and patches of parchment-like tissue; blade entire, narrowly elliptic, thickly and stiffly coriaceous, 21–27.5 × 6.5–10 cm, apex acuminate, base cuneate, adaxially semi-glossy dark green, smooth, abaxially somewhat pale yellowish green, slightly asperous; midrib thick, somewhat oblique, bluntly raised adaxially, somewhat sharply raised abaxially; primary lateral veins c. 15 per side, pinnate, very weakly differentiated and approximately equal number of interprimary veins; all other venation obscure.²

INFLORESCENCE:

Inflorescence solitary, smelling of yeast at anthesis, leaf immediately subtending usually with blade somewhat reduced and petiolar sheath proportionately longer than typical; peduncle shorter than petiole, 2–3 cm long, slightly shorter than spadix, pale milky yellow, smooth; spathe 4–5.5 cm long, ellipsoid with terminal portion stoutly rostrate, smooth, fleshy, hardly opening during anthesis and entirely deciduous soon after anthesis, both surfaces milky yellow; spadix cylindric, stout, shorter than spathe, c. 2.5 cm long, milky yellow; flowers bisexual; pistil hexagonal-columnar, 4–5 × c. 3 mm; stylar region hexagonal; stigma sessile, punctiform to somewhat elliptic, pale yellow at pistillate anthesis and then with a conspicuous droplet, drying and becoming sunken and dark post pistillate anthesis; ovary unilocular; ovule solitary, campylotropous; placentation basal; anther elliptic; pollen fully zonate, hamburger-shaped, medium-sized, psilate, c. 25 µm in diam.; infructescence a "monsterocarp" ripening dull greenish brown, stylar plates sloughing at maturity to reveal pale cream pulp fragrant of fermenting pineapple; fruit single-seeded; seeds large, c. 3 mm in diam., kidney-shaped; testa bony, pale yellow.²

ECOLOGY:

Found in scrubby ridgetop kerangas or open kerangas forest on slopes at 1400–2500 m in the northern and southern Crocker Ranges of Sabah, notably around Mount Kinabalu and north to the Sir James Brooke Range, as a low climber or scandent semi-terrestrial shrub, flowering mainly in plants fully exposed to sun.² altitude: 1400–2500 m

ETYMOLOGY:

Of Mount Kinabalu in Sabah, where the Clemenses collected the type at Tenompok in 1932; the epithet is Furtado's, from the basionym Rhaphidophora kinabaluensis.²

NOTES:

1. Furtado had described the plant as a Rhaphidophora; the thick blade texture and obscure venation of the long-petioled leaves suggested Scindapsus, and dissection of fresh inflorescences from Mount Kinabalu showed every pistil to have a solitary ovule on a basal placenta, which settles the genus. The species belongs to the informal Scindapsus Coriaceus Complex, defined by thickly leathery blades with all venation rather obscure or at most the primary lateral veins visible, smooth stems, a semi-terrestrial to scandent shrubby habit that is at most low-climbing, a marked preference for exposed situations in kerangas, and solitary inflorescences with a thick to very thick leathery spathe.²

2. Many inflorescences examined at pistillate anthesis contained the flea beetle Chaloenus nitidicupreatus and an unidentified scarab of the genus Peltonotus. Kartini, Siva Rohgini and Boyce also observed that the Coriaceus Complex is adapted to almost xerophytic conditions for part of the year and to intense sunlight, an ecology matched among aroids only by the largely lithophytic Brazilian species of Anthurium section Urospadix, and that fieldwork in Sabah, Sarawak and Kalimantan shows the complex to be manifestly under-described.²

STORY:

STORY TITLE: The Rhaphidophora that was a Scindapsus

In March and April 1932 Caetano Xavier Furtado spent six weeks on Mount Kinabalu with Joseph and Mary Strong Clemens, and among the aroids he described from that trip in 1935 was a low climber of the open ridges, which he called Rhaphidophora kinabaluensis. The name went unnoticed for eighty years. When Peter Boyce revised the Bornean species of Rhaphidophora in 2001 he overlooked it altogether, and it was only in 2015 that Kartini Saibeh, Siva Rohgini Batumale and Boyce went back to the Clemens duplicates and found that the plant did not look like a Rhaphidophora at all. The thick blade texture and the almost invisible venation of its long-petioled leaves matched two informal groups of Scindapsus instead.²

The two genera are separated on the ovules. A Rhaphidophora pistil carries numerous ovules on one or two intrusive parietal placentas and ripens many small ellipsoid seeds; a Scindapsus pistil carries a single ovule on a basal placenta and ripens one large kidney-shaped seed. Dissecting the very tough inflorescences of the Monstereae wrecks them, which rules out the type specimens, so Siva Rohgini, then an undergraduate at Universiti Malaysia Sabah writing a thesis on the Scindapsus of Mount Alab, examined fresh inflorescences from populations around Kinabalu that were plainly Furtado's plant. Every pistil, at pistillate and at staminate anthesis, held one ovule on a basal placenta. The transfer to Scindapsus followed.²

The species belongs to what the authors call the Scindapsus Coriaceus Complex: thick, stiffly leathery blades with the veins hidden, smooth stems, a semi-terrestrial to scandent habit that climbs only a little, a taste for exposed situations in kerangas, and solitary inflorescences wrapped in a thick, tough spathe. Scindapsus kinabaluensis grows on scrubby ridgetop kerangas between 1400 and 2500 m, flowers mainly where it stands in full sun, and its inflorescence smells of yeast at anthesis. Many of the inflorescences opened at pistillate anthesis held beetles, the flea beetle Chaloenus nitidicupreatus and an unidentified scarab of the genus Peltonotus, and the ripe infructescence sheds its stylar plates to expose pale cream pulp that smells of fermenting pineapple. The authors point out that this is an unconventional ecology for a family of the humid tropics: the complex endures almost xerophytic conditions for part of the year and intense sunlight for part of every day, and its closest ecological match among aroids is the largely lithophytic Brazilian Anthurium of section Urospadix.²

Seven species of the complex had names in 2015, and fieldwork in Sabah, Sarawak and Kalimantan showed the group to be manifestly under-described. The Compendium of Malesian aroid genera published the same year put the whole genus at perhaps 60 species, about half of them still unnamed, and noted that climbing aroids are usually ignored by collectors as too difficult to sample.²,⁴

REFERENCES:

1. Plants of the World Online, Royal Botanic Gardens, Kew — Scindapsus kinabaluensis

2. Willdenowia 45: 410 (2015) — protologue.

3. iNaturalist: Scindapsus kinabaluensis

4. Boyce & Wong 2015. Compendium Genera Aracearum Malesianum. Aroideana 38E(1): 40–177

Additional photos by Patrick Blanc

Additional photos from iNaturalist by mdoliveira, Lars Mannzen, Albert Kang, Huang Baochen / 黄宝臣, Kinmatsu Lin, Nelson Wong, Shawn O'Donnell, Sonia Molino, helen_m, 黃美滿, Oliver Ingold and Tony Rodd