Myrialepis paradoxa (Kurz) J.Dransf., Kew Bull. 37: 242 (1982)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Cambodiapresent (World Checklist of Arecaceae)A
Malayapresent (World Checklist of Arecaceae)A
Myanmarpresent (World Checklist of Arecaceae)A
Sumaterapresent (World Checklist of Arecaceae)A
Thailandpresent (World Checklist of Arecaceae)A
Vietnampresent (World Checklist of Arecaceae)A

Discussion

  • The involved synonymy reflects the paucity of good herbarium material of this rattan. As far as I know there is only one collection of Myrialepis bearing staminate flowers from the Malay Peninsula-Moore 9075. The concept of Myrialepis in Malaya was based on pistillate material without reference to staminate material, whereas in Burma and Indochina, the same taxon, based on staminate material was regarded as belonging to Plectocomiopsis. Gagnepain was able to show that Indochinese P1. floribunda bore fruit with minute scales, and should thus be included in Myrialepis. Beccari (1918) in his notes on P1. floribunda and P1. paradoxa discussed the uncertainty of the assignment of his two taxa to Plectocomiopsis and, indeed, included a question mark after the genus in his citation. This suggests, of course, that the limits of the two genera were not sufficiently clear to Beccari. With more material, a better understanding of the genera has been reached. Gagnepain (1937) based his new genus Bejaudia on fragmentary material collected in Cambodia by the French forester Marcel Bejaud (No. 1) and in Vietnam by Pierre (4855); Pierre's collection is sterile. The type, Bejaud No. 1, consists of parts of a staminate inflorescence in bud, and of a single leaf fragment taken from the apex of an ecirrate leaf. Gagnepain referred Bejaudia to the group comprising Plectocomiopsis and Myrialepis. He stated it could not be Plectocomiopsis because the leaflets are neatly punctate with pale scales on the undersurface, the rachillae straight rather than scorpioid, and the anthers directly attached to the filaments or androecial lobes rather than to a fine filament. Similarly it could not be Myrialepis because the leaflets are armed with strong spinules, the rachillae straight and many-flowered, and again, because the anthers are directly attached to the filaments. Gagnepain regarded the sessile anthers as being sufficient to delimit a new genus, quite apart from the other features. I have examined the type in detail; the structure of the leaf fragment is indistinguishable from that of the type of Myrialepis floribunda apart from the abundance of spinules, yet spinules are present in the latter. This abundance of spinules could be explained if the leaf originated from an exposed young shoot, as indeed the ecirrate state suggests. The details of the flower were completely misrepresented by Gagnepain. The anthers are in fact borne on very slender filaments at the tips of the lobes of the androecial tube, and are quite indistinguishable from flowers of Myrialepis. The rather pronounced sagittate base is a feature of immature flowers. It is supposed that Gagnepain did not soak out sufficiently the flowers he examined, and thus missed the slender filaments. There is one feature, however, which gives a superficial distinction to the inflorescence. In the type of Bejaudia the rachillae are straight, rather than curved, and bear many flowers. I propose that the inflorescence fragments in the type are in fact tips of inflorescences rather than tips of first-order branches and that the rachillae are second- rather than third-order branches; this is supported by the rare presence near the base of the inflorescence fragment of the type of curved third-order branches more or less indistinguishable from those of Myrialepis. This ability to produce flowers on second- or third-order branches has also been observed in pistillate Myrialepis in Malaya (see notes on inflorescence structure) and here too lends a somwhat dissimilar appearance to the inflorescence. In Bejaudia, furthermore, the bracts and their indumentum are identical to those of young Myrialepis. I have now no hesitation in referring Bejaudia to Myrialepis, and the species to M. paradoxa. (J. Dransfield, A Reassessment of the Genera Plectocomiopsis, Myrialepis and Bejaudia (Palmae: Lepidocaryoideae). 1982)B

Biology And Ecology

Description

  • Robust clustering thicket-forming rattan with stems ultimately to 40 m or more, without sheaths to c. 4 cm diam., with sheaths to 7 cm, much less in juvenile plants; internodes to 40 cm, the surface covered in reddish-brown scales. Leaf-sheaths coarse, sparsely to densely covered in reddish-brown scales and variously armed; sheaths of juvenile stems with neat distant whorls of long pale straw-coloured spines to 4 cm; mature sheaths with much fewer, ± scattered or slightly grouped spines; knee absent. Ocrea very incon- spicuous, scarcely developed. Leaf 3-5 m including petiole 5-20 x 2 cm and cirrus to 1.5 m; leaflets rather coarse and distant ± regular or grouped in 2's-3's, to 45 x 5 cm, with few to many marginal spines to 3 mm, concolorous but with scattered scales on abaxial surface. Staminate and pistillate inflorescences superficially similar, to 75 cm or more long, with up to 25 pendulous or twisting branches to 30 cm. Staminate flower to 4 x 1.5 mm; calyx tubular in lower 1 mm, with 3 triangular apiculate lobes to 1 x 1 mm; corolla tubular in basal c. 1 mm with 3 triangular tipped petals to 3 x 1.5 mm; lobes of androecial ring to 4 x 0.5 mm, with pendulous filaments to 1.5 x 0.1 mm, and anthers to 1.2 x 0.4 mm, oblong, sometimes somewhat sagittate. Pistillate flower to 4.5 x 3 mm; calyx tubular in lower 1 mm, with 3 triangular lobes to 1 x 3 mm; corolla tubular in basal 1 mm with 3 triangular petals to 3.5 x 3 mm; staminodal ring tubular in basal 1.5 mm, bearing 6 triangular lobes to 1 x 1 mm; empty anthers sagittate to 0.4 x 0.2 mm; ovary spherical c. 2.5 mm diam. tipped with stigmas to 0.7 mm; scales c. 0.1 x 0.05 mm. Ripe fruit somewhat oblate to 2.5 x 3 cm tipped with black stigmas, covered in greenish grey scales like sharkskin. Seed c. 1.5 x 2 cm. (J. Dransfield, A Reassessment of the Genera Plectocomiopsis, Myrialepis and Bejaudia (Palmae: Lepidocaryoideae). 1982)B