Livistona carinensis (Chiov.) J. Dransf. & N.W.Uhl, Kew Bull. 38: 200 (1983)

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Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Djibouti present (World Checklist of Arecaceae)B
Somalia present (World Checklist of Arecaceae)B
Yemen present (World Checklist of Arecaceae)B
Djibouti, Somalia and Yemen. In the Horn of Africa, in Djibouti in the Goda Mts, and in Somalia at Carin, Uncad, Galgala, Marajo, Duud Shabeel and Xamur. In Yemen in the Hadramaut region at El Mintaq and Wadi Hadjer. (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))A

Habitat

  • Grows in or adjacent to intermittently flowing streams or soaks in valley bottoms, but never fully dry soils, in semi-arid regions with rainfall less than 400 mm per annum, at 200-975 m alt. (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))A

Discussion

  • The geographic isolation of Livistona carinensis, some 4000 km from the nearest Livistona species in northeast India, introduces interesting questions with respect to historical distribution and phylogeny. Based on morphology it is similar to species in western and northwestern Australia, but this appears to be an example of ecological convergence.

    Recent molecular analysis (Isagi et al., in prep.) places it close to L. jenkinsiana. Livistona carinensis was first described by Chiovenda (1929) as a Borassoid palm and named Hyphaene carinensis with the specific name derived from the site of its collection in the Carin region of Somalia. The type specimen, Puccioni & Stefanini 1027, was collected in 1924. The original description was based solely on leaf material as flowers and fruit were not collected. Subsequently, the generic determination was not soundly established, and the species true affinities were open to question. Chevalier (1939) suggested that it was a species of Medemia: 'peutêtre M. argun P.G. von Wurtemberg connu seulement en Nubie', a genus from northeast Africa also in the Borassoid group of palms.

    However, it was the German palm specialist, Burret (1943), in his treatment of the Arabian palms, who correctly recognised it as a Coryphoid palm and assigned it to a new genus, Wissmannia, named after the discoverer of the palm in Yemen, H. von Wissmann, and thus established the name Wissmannia carinensis (Chiov.) Burret. Burret only had leaves at his disposal, so there still remained questions about the affinities of the species. The first complete description, including flowers and fruit, was provided by Monod (1955) based on specimens collected in Djibouti by E. Chédeville. Monod noted the similarity of its flowers and fruit to Livistona, but did not introduce any taxonomic changes and maintained the species in Wissmannia. Tomlinson (1961), in a study based on leaf anatomy, provided data that suggested that there was no single character that could be used to separate Wissmannia from Livistona, but that by invoking a suite of characters, all of which were otherwise shared with certain species of Livistona, it was a distinct genus. Moore (1973, 1977) and Langlois (1976), similarly, indicated a close relationship with Livistona but maintained taxonomic distinction. Based on this evidence and with further study, Dransfield and Uhl (1983a) provided the formal transfer of Wissmannia to Livistona, and established the name Livistona carinensis. Livistona carinensis is listed as a critically endangered species.

    Reports on the palm's ecological status have been prepared by Welch and Welch (1998, 1999) and Ford and Bealy (2004). Surveys in Djibouti, Somalia and Yemen, resulted in the location of all adult palms, and with a total of less than 1800 palms. Compared to reports on population numbers taken 10-20 years previously, there had been a decline in numbers of 23-59% across all locations. The primary causes of such rapid decline are the cutting down of the palms for timber, or the clearance of land for agriculture. There is no active program to conserve this species in either Somalia or Yemen, but the Government of Djibouti has developed a conservation plan.
    (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))A
  • The occurrence of Livistona carinensis in Djibouti, northern Somalia, and southern Yemen, so distant from remaining species of the genus, has fascinated many palm biologists. First recognized as a species of Hyphaene, it was placed by Burret in the monotypic genus Wissmannia in 1943. However, on grounds of close morphological and anatomical similarities, Dransfield and Uhl (1983) reduced W. carinensis into synonymy with Livistona (see also Tomlinson 1961a, Monod 1955). The placement of L. carinensis within Livistona sensu stricto is strongly supported by our DNA data. Our biogeographical results are consistent with Dransfield and Uhl's (1983) hypothesis that the distribution of Livistona was once much more widespread during the time of the northern boreotropical forests (Miocene; about 5-24 million years ago) and that, due to geological and climate changes, L. carinensis became isolated in the African-Arabian region in a relict forest fragment. In our phylogenetic analysis, L. carinensis is resolved on a long branch as sister to all the remaining Livistona species, which suggests that there have been high levels of extinction within this lineage. Nevertheless, there is no current phylogenetic justification for recognizing Wissmannia, and given its high morphological similarity to Livistona, it is most appropriate to retain it within the revised circumscription of this genus. (Bacon. C.D. & Baker, W.J. 2011: Saribus Resurrected. – Palms; Journal of the International Palm Society 55: 109-116)C

Diagnosis

  • Livistona carinensis is a large canopy palm to 40 m tall; leaves are large and regularly segmented; segment apices are rigid, and with a bifurcate cleft to 50% of the segment length; the petiole is armed with very large spines; the inflorescence is unbranched, extending beyond the limit of the crown and pendulous, and with up to 12 partial inflorescences; bracts are tubular; flowers are yellowish green with long unbranched hairs on the sepals and petals; the rachillae are also covered with long unbranched hairs; fruit are globose, to 5-20 (50) mm diameter, and dark brown to black at maturity. (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))A

Conservation

  • Vulnerable (IUCN, 2006), but here upgraded to Endangered based on Welch & Welch (1999) and Ford & Bealy (2004). (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))A

Common Name

  • Bankouale Palm, Nakilto (Afar), Daban, Madah (Somali), N,tug, somm (Arabic). (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))A

Description

  • Hermaphroditic palm. Trunk to 40 m tall, ca 40 cm dbh, leaf scars prominent, slightly oblique, irregular in width, internodes narrow, petiole stubs persistent in the lower 1-2 m. Leaves 30-40 in a globose to conical crown; petiole to 125 cm long, 5-8 cm wide proximally, 1-2 cm wide distally, adaxially flat to shallowly concave, bright orange-yellow-green, margins armed with large single or double, dark brown curved spines throughout, but largest and closer in the proximal portion; spines conical, basally swollen, apically acute, retrorsely recurved, brown-black, 7-25 mm long, 3-10 mm wide at the base, 8-15 mm apart, reduced to tubercles in the distal portion of the petiole, 4-6 cm apart; leaf-base fibres prominent, fine, persistent; appendage rigid, 6-7 cm long, brown to black; lamina costapalmate, regularly segmented, subcircular in outline, 80-95 cm long, thick, both surfaces waxy, glabrous, grey-green on adaxial surface, grey abaxially,drying chartaceous; lamina divided for 75-85% of its length, with 50- 70 segments, depth of apical cleft 40-50% of the segment length, apical lobes rigid, segment midrib very prominent; parallel veins 18-20 each side of midrib; transverse veins thinner than parallel veins, inconspicuous on the surface; segment margins thickened, with a deciduous filament,the remains of which persist where the segments diverge from adjacent segments; lamina anatomically isolateral, hypodermis 1-layered below each surface (not with a 2?layered adaxial hypodermis as in other species, cf. Tomlinson, 1961). Inflorescences unbranched at the base, 200-240 cm long, extending beyond the limit of the crown by ca 20 cm, slender, arching, eventually pendulous, branched to 3 orders; partial inflorescences 6-12; rachillae very thin, yellowish, with scattered long hairs; peduncular bract 1, glabrous; rachis bracts tubular, brown red, striate, glabrous. Flowers in clusters of ca 5, ca 2 mm long, yellow-green, abaxial surface of perianth segments with scattered long hairs; sepals much shorter than the petals, irregular, margins hyaline, scattered long hairs on the abaxial surface near the apex; petals apically pointed, scattered long hairs near the apex; filaments basally connate; carpels scarcely fused, similarly the styles. Fruit globose, 5-20 (50) mm diam., dark brown to black; epicarp thin, dull, shallowly rugose in the fresh state, deeply rugose in the dried state; stigmatic remains apical; suture line extends for the length of the fruit; mesocarp greenish with very large sclerenchymatous cells; mesocarp very thin, adhering to the endocarp; pedicel narrow, 4-5 mm long. Seed globose; intruded by the seed coat to displace most of the endosperm; embryo sublateral. Eophyll 7-ribbed. (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))A

Materials Examined

  • Specimens examined: SOMALIA: Carin. Oasis of Uncud, Puccioni & Stefanini 1027 (FT holotype); Galgala, 10º58'N, 49º02'E, Barbier 972 (K); Galgala, 25 km W of Carin, 10º59'N, 49º02'E, Lavranos & Carter 24835 (K). DJIBOUTI: Bankouale Wadi, Nov. 1985, Coghlan s.n. (K); Bankouale, 2000, Welch s.n. with Welch (K). (Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae))A

Bibliography

    A. Dowe, J.L.: A taxonomic account of Livistona R.Br. (Arecaceae)
    B. World Checklist of Arecaceae
    C. Bacon. C.D. & Baker, W.J. 2011: Saribus Resurrected. – Palms; Journal of the International Palm Society 55: 109-116