Livistona exigua J.Dransf., Kew Bull. 31: 760 (1977)

https://media.e-taxonomy.eu/palmae/photos/palm_tc_114926_6.jpg

Content

Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)

Borneo present (World Checklist of Arecaceae)C

Known only from a single collection from Borneo (Brunei). (Dransfield, J. 1977: A dwarf Livistona (Palmae) from Borneo)A

Brunei. Belait District, Ulu Ingei. (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))B

Habitat

In forest transitional between lowland Dipterocarp forest and kerangas (heath forest) on sandstone, at 60-260 m alt. (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))B

Discussion

This palm would probably make an extremely attractive subject for cultivation and it is to be hoped that it can be recollected. (Dransfield, J. 1977: A dwarf Livistona (Palmae) from Borneo)A
Livistona exigua was described by Dransfield (1977) based on the collection Ashton BRUN5513 collected from the Belait District, Brunei, in 1959, and named with reference to the palm's small stature. This collection had remained as unidentified material in Kew, but with examination by Dransfield was recognised as a new species. It has provided a considerable ecological extension for the genus, as a rainforest understorey palm in kerangas heath, which was previously not recorded in Livistona. Livistona exigua is an understorey palm to 5 m tall; leaves are small, and have grouped segments and deep divisions between the groups; segment apices are rigid; the inflorescence is unbranched, not extending beyond the limit of the crown, and with up to four partial inflorescences; flowers are purplish; fruit are globose, to 9 mm diam., and purplish green at maturity. (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))B

Diagnosis

a ceteris speciebus Livistonae ampli- tudine minima, caule usque 1.3 m alto, 2.-5 cm diametro, folio minimo 50 cm diametro, in foliola latitudinis variabilis irregulariter diviso, inflorescentia erecta rigida minuta 30-40 cm alta, rachillis paucissimis trichomatibus inflatis dense tectis, floribus minutis circiter I mm diametro, sepalis extra trichomatibus inflatis dense tectis, fructu parvo 9 mm diametro, differt. (Dransfield, J. 1977: A dwarf Livistona (Palmae) from Borneo)A

Biology And Ecology

Dr. P. S. Ashton (pers. comm.) recalls that the area where the palm grew is on shallow podsolic sands in forest ecotonal between mixed Dipterocarp and Heath forest on Miocene and Pliocene sandstones belonging to the Belait formation. (Dransfield, J. 1977: A dwarf Livistona (Palmae) from Borneo)A

Conservation

Near threatened. (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))B

Description

Small forest undergrowth palm. Stem ? solitary or ? clustered (no details known) to 1.3 m tall by circa 2.5 cm in diameter. Leaves apparently about Io in the crown; leaf sheath dull dark brown, extending 12.5 cm next to the petiole and to 30 cm opposite the petiole where it forms a papyraceous tongue, shiny within, tattering to form a close network of fibres enclosing the base of the leaves and inflorescences; petiole to 60 cm long by 6 mm wide below, tapering to 3 mm near the lamina insertion, spiny along the margins in the lower third, with spines blackish-brown, c. 4 mm long and 5 mm distant, reflexed and with slightly swollen bases, the petiole surface with scattered caducous pseudoparenchymatous peltate scales ab- and adaxially; lamina with a spread of circa 50 cm, the adaxial hastula conspicuous to 5 mm wide and 2-3 mm high, unarmed, of variable dissection (3 individuals examined) with 20-30 adaxial ribs split into 10-13 apparently moderately stiff leaflets of varying width ranging from compound leaflets with 2-6 folds to single fold leaflets (e.g. one leaf with one outer compound leaflet 5 folds wide followed by 3 single fold leaflets, followed by one compound leaflet 3 folds wide followed by one single fold leaflet followed by central compound leaflet 5 folds wide), the primary divisions of the lamina to within 2-3 cm of the hastula, the single folds 1-1.5 cm wide in mid-lamina and tapering to very fine tips split into two teeth by a split c. 1.5 cm deep, the ad- and abaxial ribs with scattered dark brown caducous pseudoparenchymatous scales, transverse veins prominent, the abaxial surface of the lamina with scattered scales, adaxial surface with very few. Inflorescence between the leaves, variable in size, possibly elongating with age, 30-40 cm in all, with peduncle 20-25 cm below the first partial inflorescence, the first partial inflorescence diverging just above the leaf sheath; bracts 4, the first 2-keeled and empty, bilobed at the top, to 18 cm long, dark brown with pale brown scurfy indumentum along the keels, minutely longitudinally striate, subsequent bracts similar and each subtending a partial inflorescence; partial inflorescences with branches up to the second order, the whole partial inflorescence to 7 cm long, usually less; axis and rachillae densely covered with inflated indumentum and papillae, appearing very rough under magnification; rachillae 6-10 in each partial inflorescence, to 6 cm long, apparently stiff, digitate, densely covered in flower groups, each subtended by a fimbriate bract c. 0.2 mm high; flowers usually paired, one of the pair older than the other, each subtended by a minute fimbriate bracteole, scarcely distinguishable amongst the inflated indumentum, the flower pair (in dry material) somewhat sunk within the rachilla. Flowers hermaphrodite, minute, c. I mm in diameter at anthesis. Sepals 3, joined for about half their length to form a short tube c. 0.3 mm high with lobes c. 0.2 mm high, rounded, fimbriate, densely covered with inflated indumentum without. Petals 3, glabrous, broadly triangular, c. 0-4 mm high, joined for about 1/4 of their length to form a very short basal ring. Stamens 6, minutely epipetalous, glabrous, to c. 2 mm high, joined by their swollen filament bases; anthers minute; pollen yellowish. Gynoecium of 3 closely adpressed free carpels joined apically to form a style c. 0.2 mm long, glabrous. Fruit (apparently almost mature) globose, c. 9 mm in diameter with remains of calyx, corolla and androecium basally and marked with a line running from apex to base; epicarp smooth; mesocarp c. 1.5 mm thick with numerous tannin cells; endocarp c. 0.3 mm thick. Seed (not quite mature) covered by thin brown integument with convoluted mass (postament) penetrating at the chalazal end. (Dransfield, J. 1977: A dwarf Livistona (Palmae) from Borneo)A
Hermaphroditic palm. Trunk to 5 m tall, 1.5-2.5 cm dbh, leaf scars raised, irregular in width, internodes narrow, irregular in length, pale brown, petiole stubs not persistent. Leaves 16-20 in a vertically ovoid crown; petiole 40-60 cm long, slightly arching, proximally ca 6 mm wide, tapered to ca 3 mm wide distally, adaxially flat, armed on the margins in the lower one-third, upper margins sharp, slightly winged; petiole surface with scattered caducous pseudo-parenchymatous peltate scales on both surfaces; spines retrorsely recurved, brown, to 4 mm long, bases swollen, regularly placed at ca 5 mm apart; leaf-base fibres prominent, coarse, closely woven, dull dark brown, persistent; appendage to ca 30 cm long; lamina palmate, irregularly segmented, with segments grouped and with divisions between each group of segments deeper into the lamina than the divisions between individual segments, circular, ca 50 cm wide, adaxially midgreen, abaxially lighter green, adaxially glabrous, scattered brown scales abaxially; lamina divided for ca 42% of its length, with 16-30 segments that are single or grouped into 2-6 segments, depth of apical cleft ca 8% of the segment length; segments to 25 cm long, widest at mid segment, 1.0-1.5 cm wide, acuminate toward both apex and base, apical lobes rigid, finely toothed; parallel veins 5-6 each side of midrib; transverse veins ± same thickness as parallel veins; hastula conspicuous, to 5 mm wide and 2-3 mm high. Inflorescences unbranched at the base, 15-40 cm long, not extending beyond the limit of the crown, straight to slightly curving, branched to 2 orders; partial inflorescences 3-4; peduncle 20-25 cm long, elliptical in cross-section; prophyll tubular, to 18 cm long, dark brown with pale brown scurfy indumentum along the keels, minutely longitudinally striate, the apices acute; peduncular bract(s) lacking; rachis bracts loosely tubular; partial inflorescence axes covered densely with indumentum and papillae; rachillae 6-10 cm long, rigid, to ca 2.5 mm diameter. Flowers solitary or paired, sessile, purplish, subtended by a fimbriate bract ca 0.2 mm high, ca 1 mm diam.; sepals fused for ca half their length to form a short tube ca 0.3 mm high, lobes ca 0.2 mm high, rounded, fimbriate, abaxially densely covered with indumentum; petals broadly triangular, glabrous, ca 0.4 mm high, basally fused for ca one-quarter their length; stamens ca 2 mm high, basally fused, swollen; carpels glabrous, style ca 0.2 mm high. Fruit globose, ca 9 mm diam., purplish-green; epicarp smooth; suture line extending the full length of the fruit; mesocarp ca 1.5 mm thick with numerous tannin cells; endocarp crustaceous, ca 0.3 mm thick; pedicel 1-2 mm long. Seed globose. Eophyll not seen. (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))B

Materials Examined

BORNEO. Brunei, Belait District, Ulu Ingei, yellow sandy soil, low hill circa 6o m altitude, Aug. 1959, Ashton BRUN 5513 (K, holotype; BH, BO, L, SAR, isotypes). (Dransfield, J. 1977: A dwarf Livistona (Palmae) from Borneo)A
BRUNEI DARUSSALAM: Belait District, Ulu Ingei, ca 60 m alt., Ashton BRUN 5513 (BH, BO, L, K holotype, NY, SAR); Ulu Ingei, Bukit Batu Patam, 04°5?N, 114°42?E, 200 m alt., ridge top kerangas forest, transitional to mixed Dipterocarp forest, abundant miniature serdang forming thickets on ridge tops, Dransfield JD6568 with Wong Khoon Meng, Dransfield & Boyce (A, K, SING); Ulu Ingei, 150 m alt., Jan 1982, Morgan s.n. (K, SING). (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))B

Bibliography

A. Dransfield, J. 1977: A dwarf Livistona (Palmae) from Borneo

B. Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae)

C. World Checklist of Arecaceae

Main menu

Classification

Search taxa

Palm Resources

Search other databases

For your info