Benthamia lakatoensis Descourv. & Hervouet, 2025

Hervouet, Jean-Michel, Descourvières, Pascal, Hermans, Johan & Longou, Ludivine, 2025, Revision of the genus Benthamia A. Rich. (Orchidaceae, Orchidioideae, Habenariinae), Adansonia (3) 47 (11), pp. 171-249 : 209

publication ID

https://doi.org/10.5252/adansonia2025v47a11

persistent identifier

https://treatment.plazi.org/id/039B87AB-FFFC-FFCF-238D-F4A82E64C4E1

treatment provided by

Plazi

scientific name

Benthamia lakatoensis Descourv. & Hervouet
status

 

Benthamia lakatoensis Descourv. & Hervouet , sp. nov.

( Figs 54; 55 View FIG ; 56 View FIG ; 57 View FIG )

DIAGNOSIS. — Similar to Benthamia nivea but differing by the shape of the leaves, elliptic with apex rounded (vs elliptic with apex acute in Benthamia nivea ), and in the smaller flowers, 4-6 mm (vs 5-10 mm for Benthamia nivea ), forming a straight tube in their lower third (vs forming a curved tube), with petals not or hardly asymmetrical (vs completely asymmetrical), lateral lobes of lip divergent (vs parallel when flattened), base of lip narrow, hardly wider than the midlobe (vs base of lip twice wider than the midlobe), the dorsal sepal and petals ending in a single vertical plane in fresh specimens (vs flowers not opening widely). The auricles are nearly twice as long and the column is much less apiculate, the spur is half the length. The flowering season is August-November (vs February-April).

TYPE MATERIAL. — Madagascar Alaotra-Mangoro, route de Lakato; 19°11’30”S, 48°26’00”E; XI.1963; J. Bosser 18340; holotype: P [ P00094562 ] !.

ETYMOLOGY. —Referring to « Lakato », a village near Andasibe in the Alaotra-Mangoro region, where the type of the plant was first found. PHENOLOGY. — August to November.

DISTRIBUTION AND ECOLOGY. — Madagascar. Only few plants have been recorded so far, from c. 725 to 1200 m, in medium altitude moist evergreen forest, from north to south. The type was collected along the road between the Route Nationale 2 and Lakato, a region that has suffered from severe deforestation in the recent years, it is very unlikely that it still exists there. A specimen has been located in Zahamena forest reserve, another one in Ranomafana national park, and more recently another from Tsaratanana area ( Fig. 56 View FIG ).

CONSERVATION. — Apart from the specimens found recently, this species has been collected in two localities only, one of them (road to Lakato) being heavily deforested. It can be considered Critically endangered (CR) according to criterion B2, with AOO less than 10 km ², severely fragmented and in continuing decline.

ADDITIONAL SPECIMENS EXAMINED. — Madagascar • Alaotra-Mangoro, massif de l’Andrangovalo au sud-est du lac Alaotra, réserve de Zahamena; 17°40’S, 48°45’E; alt. 1200 m; X.1937; H. Humbert et al. 17922; P [ P00094547 ] ! • Haute Matsiatra, parc national de Ranomafana, parcelle n°1, 26.VIII.1992; R. Rakoto 208; P [ P00692459 ]!, K!, MO [ MO3022622 ] ! • Alaotra-Mangoro, Lakato, Bosser 17229; Jean Bosser and Jean-Pierre Peyrot slides. It is very likely that the specimen Bosser 17229 referred to in the Bosser slide collection is in fact Bosser 18340, there is no specimen Bosser 17229 in P Diana, Ambanja district ; alt. 725 m; 20.XI.2022, L. R. Rajaovelona RJL1662; K [ K001304657 ] !.

J

University of the Witwatersrand

P

Museum National d' Histoire Naturelle, Paris (MNHN) - Vascular Plants

H

University of Helsinki

R

Departamento de Geologia, Universidad de Chile

K

Royal Botanic Gardens

MO

Missouri Botanical Garden

L

Nationaal Herbarium Nederland, Leiden University branch

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