Tahina J.Dransf. & Rakotoarin., Bot. J. Linn. Soc. 156: 81 (2008)

Primary tabs

http://media.e-taxonomy.eu/palmae/photos/palm_tc_351389_15.jpg

Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Madagascar
Tahina spectabilis is known from a single locality in north-western Madagascar. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Discussion

  • This astonishing palm was discovered as this book went to press. It is distinguished from all other fan-palms in Madagascar by its hapaxanthic habit. The tubular bracts on the rachillae are very reminsiscent of those of Chuniophoenix. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Diagnosis

  • Spectacular massive solitary hapaxanthic hermaphroditic fan palm of north-western Madagascar, with huge leaves and unarmed petioles with a distinctive triangular cleft at the base of the petiole, and huge suprafoliar compound inflorescences. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A
  • Palma grandis hapaxantha, foliis costapalmatis, petiolo inerme, basin fissure triangulare, lamina induplicate, plicatis aliquot ordinium; inflorescentia terminalis suprafoliaris, numerosis inflorescentiis lateralibus composita, rachillis bracteas tubulosas, imbricatas ferentibus, cincinnos florum subtendentibus; flores hermaphroditi; calyx membranaceus, tubulosus, trilobus, lobis brevibus; corolla basin ad receptaculum connata, distale petalis imbricatis; stamina 6; gynoecium syncarpum, tricarpellatum, triovulatum; fructus vestigio stigmatum apicali, epicarpio laeve, mesocarpio carnoso, fibroso, endocarpio membranaceo; endospermium ruminatum, embryone subbasali. (J. Dransfield & M. Rakotoarinivo & W.J. Baker & R.P. Bayton & J.B. Fisher & J.W. Horn & B. Leroy & X. Metz, A new Coryphoid palm genus from Madagascar. 2008)B

Biology And Ecology

  • It grows at low elevation on seasonally flooded soils at the foot of a karst limestone outcrop; there are 91 individuals of varying size and a few hundred 1-leaf seedlings originating from the 2007 fruiting known. When in flower, the immense compound terminal inflorescence appears to go through three successive waves of anthesis. Nectar production is so copious that the entire inflorescence appears coated with honey, attracting large numbers of bees, wasps and flies. Greater Vasa Parrots (Coracopsis vasa) attack the young fruit (N. and X. Metz, pers. comm.). Nothing is known of fruit dispersal. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Common Name

  • Dimaka, a name also applied to Borassus, Bismarckia and Dypsis decipiens. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Etymology

  • Tahina — Malagasy for blessed, or to be protected, also the given name of the daughter of the discoverer of the palm. (J. Dransfield & M. Rakotoarinivo & W.J. Baker & R.P. Bayton & J.B. Fisher & J.W. Horn & B. Leroy & X. Metz, A new Coryphoid palm genus from Madagascar. 2008) (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A,B

Uses

  • No local uses have been recorded. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Description

  • Massive, solitary, unarmed, hapaxanthic, hermaphroditic, tree palms. Stem erect, rather distantly ringed with leaf scars. Leaves induplicate, costapalmate, marcescent in immature individuals, tending to abscise under their own weight in trunked individuals; sheath with a conspicuous triangular cleft below the petiole, the margins tending to erode into broad lobes; petiole massive, long, covered with white wax, adaxially deeply channelled, abaxially rounded, margins smooth, adaxial hastula well developed, abaxial hastula a hard low rather irregular crest at the base of the lamina; blade divided to ca.1/2 its radius into multi-fold segments, these in turn more shallowly divided into single-fold segments, themselves shallowly divided along the abaxial folds, main abaxial ribs of blade very conspicuous, very crowded at the base of the blade, some much more robust than others, the less robust ribs tending to be inserted in a more adaxial position compared with the robust ribs; segments with prominent longitudinal veins and abundant irregularly arranged transverse veinlets, glabrous, the undersurface of the blade with thin white wax. Inflorescences above the leaves, subtended by reduced, scale like leaves, forming a massive, compound inflorescence-like structure; individual inflorescences branched to the third order, branches ending as rachillae; prophyll of inflorescences and first order branches 2-keeled, this case distal to the first and second flowers a few empty tubular bracts. Flowers borne on short stalks; distal to this, the flower with a stalk formed by the base of the calyx and the receptacle; calyx tubular basally, with 3 low, triangular lobes; petals ± boat-shaped, basally imbricate, the margins usually inrolled, apically somewhat cucullate, strongly reflexed at anthesis and with a glandular swelling at the base of each lobe; stamens 6, filaments terete, tapering from a fleshy base; anthers elongate, basifixed, introrse; gynoecium tricarpellate, syncarpous, triovulate, ovarypyramidal, angled and grooved, style short, slightly 3-grooved, stigma scarcely differentiated, ovule basally attached, anatropous. Pollen ellipsoidal, bi-symmetric or slightly asymmetric; aperture a distal sulcus; ectexine tectate, coarsely perforate-rugulate, aperture margin slightly finer; infratectum columellate; longest axis 25–55 µm; post-meiotic tetrads tetrahedral. [1/1]. Fruit ellipsoid, single-seeded with apical stigmatic remains; epicarp smooth, mesocarp fleshy and ± fibrous, endocarp scarcely distinguishable, membranous. Seed globose, with basal hilum, and deep grooves corresponding to the rapheal bundles, endosperm strongly ruminate without a central hollow; embryo subbasal. Germination remote-ligular; eophyll palmate. Cytology unknown. (J. Dransfield & M. Rakotoarinivo & W.J. Baker & R.P. Bayton & J.B. Fisher & J.W. Horn & B. Leroy & X. Metz, A new Coryphoid palm genus from Madagascar. 2008) (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A,B

Anatomy

  • Not studied. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Fossil record

  • No generic records. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Relationships

  • For relationships see Chuniophoenix. (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Taxonomic accounts

  • Dransfield et al. (2008). (J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008)A

Bibliography

A. J. Dransfield & N. Uhl & C. Asmussen & W.J. Baker & M. Harley & C. Lewis, Genera Palmarum. The evolution and classification of palms. 2008
B. J. Dransfield & M. Rakotoarinivo & W.J. Baker & R.P. Bayton & J.B. Fisher & J.W. Horn & B. Leroy & X. Metz, A new Coryphoid palm genus from Madagascar. 2008