SCINDAPSUS MACLUREI
PROTOLOGUE: Scindapsus maclurei , published in Lingnan Science Journal 21: 5 (1945).
Scindapsus maclurei (Merr.) Merr. & F.P.Metcalf, Lingnan Science Journal 21: 5 (1945). Basionym: Rhaphidophora maclurei Merr., Philippine Journal of Science 21: 337 (1922). Type: China, Hainan, Ng Chi Leng, growing over large boulders in ravines at 600 m, December 1921, F. A. McClure 8714.
SYNONYMS:
HOMOTYPIC SYNONYMS: Rhaphidophora maclurei Merr.
HETEROTYPIC SYNONYMS: Scindapsus megaphyllus Merr.
OTHER NAMES: Ngot, งด (Thai); Hai nan teng yu, 海南藤芋 (Chinese)
DISTRIBUTION: Hainan to N. Indo-China: Hainan, Laos, Thailand, Vietnam.
DISTRIBUTION NOTE: Thailand: Buri Ram, Ubon Ratchathani.
SPECIES DESCRIPTION:
Large to gigantic root-climber to 30 m. Stem 10–35 mm diam. Leaves evenly distributed but lower leaves often falling and then leaves tending to become clustered towards stem apices; petiole canaliculate, 33–62.5 cm by 6–20 mm, dark green, smooth, apical pulvinus 20–25 by 5–12 mm, basal pulvinus 2–4 cm by 7–15 mm; petiolar sheath extending to half way along apical pulvinus, at first sub-membranaceous, soon drying scarious, later breaking into regular sections and falling to leave a somewhat roughened, mid-brown scar; leaf blade oblong-elliptic, 45–100 by 25–48 cm, very stiffly coriaceous, matte green adaxially, slightly glaucous abaxially, apex acute to slightly acuminate, base shallowly and narrowly cordate; primary lateral veins parallel, barely or not differentiated from interprimary veins; interprimary veins very numerous, prominent, remaining parallel to primary vein.³
INFLORESCENCE:
Inflorescence solitary on the tips of clinging shoots; peduncle 5–8 cm by 4–10 mm; spathe canoe-shaped, 28–33.5 by 11–14 cm when pressed flat, shortly but stoutly tapering, gaping at anthesis and then caducous before anthesis is complete, exterior green, interior yellow at anthesis; spadix cylindrical, 26–28.5 by 3–4.5 cm, sessile, bluntly tapering towards the apex, dull yellow; stylar region 4–10 by 1.5–4 mm, acroscopic-trapezoid, robust, apex flattened; stigma 0.8–3 by 0.1–0.5 mm, transverse-linear. Infructescence light-green, stylar region greatly enlarged and recurved along the margins, waxy-looking, ripening yellow.³
ECOLOGY:
Found in dry dipterocarp forest, between rocks, and in lowland to hill perhumid forest.³
ETYMOLOGY:
Honors Floyd Alonzo McClure (1897–1970), the American botanist at Lingnan University in Canton who collected the type in Hainan in December 1921; the epithet is Merrill's, from the basionym Rhaphidophora maclurei.⁴
NOTES:
1. The combination in Scindapsus was published by Merrill and Metcalf in the Lingnan Science Journal in 1945, a paper not yet obtained; the species had been described in Rhaphidophora by Merrill in 1922, and Merrill's Scindapsus megaphyllus of 1930, also from Hainan, is a synonym.²
2. Scindapsus maclurei is superficially similar to two other Thai climbing aroids: Epipremnum giganteum and, especially, Rhaphidophora megaphylla. From Epipremnum giganteum it is readily separated by matte green leaf blades, cordate basally (versus rounded to acute and glossy bright green), while from Rhaphidophora megaphylla, Scindapsus maclurei may be distinguished by the transverse-elongated stigma flush with the style surface (versus capitate-punctate and raised above the style surface). The Flora of Thailand gives the range outside Thailand as China (Hainan, the type locality of the species and of Scindapsus megaphyllus) and northern Laos.³
3. The basionym, Rhaphidophora maclurei, was described by Merrill from Ng Chi Leng in Hainan, where McClure collected it (McClure 8714, December 1921) growing over large boulders in ravines at 600 m: leathery entire elliptic-ovate leaves about 45 cm long and 24 cm wide, acute or very shortly acuminate, broadly rounded-cordate at the base and slightly unequal-sided, with very numerous veins on each side, on petioles 26–32 cm long and about 1 cm thick sheathed nearly to the apex, a leathery lanceolate acuminate spathe about 18 cm long and a sessile cylindric spadix about 2 cm thick. Merrill thought it probably most closely allied to the Philippine Rhaphidophora monticola, with smaller leaves, much slenderer petioles and much shorter spathes, and separated it from the Javan Rhaphidophora montana by the larger leaves distinctly cordate at the base and the larger spathes.⁴
4. Boyce notes that a Maluku specimen of Epipremnum ceramense at Bogor had been annotated as Scindapsus maclurei on the basis of a one-seeded ovary, Epipremnum ceramense often aborting all but one ovule; he gives the range of Scindapsus maclurei as Thailand, Vietnam and Hainan.⁵
5. The Flora of China describes the plant from Hainan as a liana with a robust stem about 2.5 cm in diameter, petioles 26–32 cm long with an imbricate base and a sheath reaching the pulvinus, leathery oblong-elliptic or ovate-elliptic blades 23–46 × 12–24 cm, subcordate at the base and drying pale brown, a yellow involute-tubular spathe 18–22 cm long and a sessile cylindric spadix about 15 × 2.5 cm, flowering in November and December in dense tropical forest, creeping and climbing on trees and stone walls at 400–600 m; it separates the species from the vegetatively very similar Rhaphidophora megaphylla by the numerous primary lateral veins, not differentiated from the interprimary veins and diverging at 70–80° from the midrib, against 10–13 strongly differentiated primary veins on each side diverging at 80–90° in Rhaphidophora megaphylla.⁶
STORY:
STORY TITLE: McClure's giant from Hainan
In December 1921 Floyd Alonzo McClure, the Lingnan University botanist who would become the authority on bamboos, collected a large climbing aroid at Ng Chi Leng in Hainan, growing over big boulders in ravines at 600 m. Elmer Merrill described it in 1922 as Rhaphidophora maclurei, with leathery elliptic-ovate leaves about 45 by 24 cm, broadly rounded-cordate at the base and slightly unequal-sided, a leathery lanceolate spathe about 18 cm long and a sessile spadix about 2 cm thick, and compared it with the Philippine Rhaphidophora monticola and the Javan Rhaphidophora montana. Merrill added a second Hainan name, Scindapsus megaphyllus, in 1930, and in 1945 he and Franklin Metcalf moved the first into Scindapsus as well; the two names now stand for one species.⁴
The Flora of Thailand, where the plant was later found in Buri Ram and Ubon Ratchathani, describes a large to gigantic root-climber to 30 m with stiff, matte green blades 45 to 100 cm long on petioles up to 62 cm, a canoe-shaped spathe 28 to 33 cm long that gapes at anthesis and falls before it is over, and a dull yellow spadix 26 to 28 cm long. These measurements are substantially larger than the Hainan descriptions above; the range runs from Hainan through northern Vietnam and Laos into Thailand, in dry dipterocarp forest among rocks and in lowland to hill perhumid forest. It is easily taken for Epipremnum giganteum or Rhaphidophora megaphylla, and is separated from the latter by its very numerous lateral veins, none of them differentiated as primaries, and by a transverse-linear stigma flush with the style. The confusion runs the other way too: a Maluku specimen of Epipremnum ceramense at Bogor had been annotated as Scindapsus maclurei on the strength of a one-seeded ovary, Epipremnum ceramense being a species that habitually aborts all but one ovule.³,⁶,⁵
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Scindapsus maclurei
2. Lingnan Science Journal 21: 5 (1945) — protologue.
4. Merrill 1922. Diagnoses of Hainan plants. Philippine Journal of Science 21(4): 337–354
6. Li & Boyce 2010. Scindapsus. Flora of China 23: 15
Additional photos by Patrick Blanc
Additional photos from iNaturalist by 小铖/Smalltown, narido, bibibo1998 and Anthony Ye