Benthamia lakatoensis, Hervouet & Descourvières & Hermans & Longou, 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 : 226-227

Benthamia nivea Schltr.

( Fig. 79 )

Repertorium Specierum Novarum Regni Vegetabilis 33 ( Schlechter 1924: 31).

Benthamia nivea subsp. parviflora H.Perrier , Bulletin de la Société botanique de France 81 ( Perrier 1934: 34). — Type: Madagascar • Diana, mont Tsaratanana; 14°01’17”S, 48°57’60”E; IV.1924; H. Perrier 16478; holotype: P [ P00094560 ]!, syn. nov .

TYPE MATERIAL. — Madagascar • Vakinankaratra, flanc est du mont Tsiafajavona; 19°22’S, 47°19’E; alt. 2000 m; III.1921, H. Perrier 13507; holotype: P [ P00094557 ]!; isotypes: P [ P00094558 , P00094559 ]!, K [ K000415553 ] !).

ETYMOLOGY. — From the Latin “ niveus ”, snow-white.

PHENOLOGY. — February to May.

DISTRIBUTION AND ECOLOGY. — Madagascar. On Andringitra massif (Haute Matsiatra region), Mt. Tsiafajavona (Vakinankaratra region) and Mt. Tsaratanana (Diana region), in medium altitude moist evergreen forest, from 2000 to 2200 m. Fig. 80.

CONSERVATION. — This species is known from fewer than five localities, has an AOO less than 500 km ² and is certainly declining since it has not been seen in the wild since 2001, it is therefore considered Endangered (EN), in accordance to criterion B2 and the quotation by IUCN in 2015 (https://doi.org/10.2305/IUCN. UK.2015-2.RLTS.T69221994A69252097.en).

ADDITIONAL SPECIMENS EXAMINED. — Madagascar • sine loc.; R. Baron 5187; K! • Vakinankaratra, Manjakatompo; 19°21’25”S, 47°18’28”E; alt. 2000 m; III.1961; J. Bosser 15025; TAN ! • Vakinankaratra, au-dessus de Manjakatompo; 19°21’25”S, 47°18’28”E; alt. 2200 m; III.1961; J. Bosser 15265; P [ P00094561 ] ! • Vakinankaratra, forestry station at Manjakatompo; 19°21’25”S, 47°18’28”E; alt. 1800-2000 m; 27.III.1987; G. E. Schatz 1298; P [ P00094563 ]!, MO • Vakinankaratra, Ambatolampy area , Hort. Malala Orchidées, cultivar Madagascan Dream BC / RHS; 11.IV.2000; J. Hermans 4903; K ! • Haute Matsiatra, Andringitra; IV.2000; ex Jean Bosser, J. Hermans 5341; K ! • Diana, source of Andranomalaza; alt. 1700 m; V.2000; L. Gautier et al. LG3656 ; G00096571 ! • Haute Matsiatra, Andringitra foothills, near the village of Soavihiny; 22°05’40”S, 46°47’04”E; 5. V.2001; alt. 1506 m; J. Hermans 123; K !.

NOTES

This species is similar to Benthamia erinacea , but it differs by its thinner leaves and by the colour of the flowers. The flowers are pure white, with a wider trilobed lip. Also similar to Benthamia lakatoensis sp. nov., from which it differs by the shape and position of the floral parts and the flowering time, see the diagnosis of the latter species.

Perrier distinguished Benthamia nivea subsp. parviflora as follows: flowers smaller (5-6 mm), lateral lobes of lip acute, lip with 3 veins, staminodes (in our study named auricles) half the thickness, rostellum with 3 lobes of equal size. The type is indeed a small plant, but it remains in the variation range observed outside Tsaratanana. Lips with acute lateral lobes are also evident on the type of Benthamia nivea . The number of veins, the auricles and the rostellum are also variable. For all these reasons we prefer to consider Benthamia nivea subsp. parviflora as a synonym of Benthamia nivea .

The gathering H. Perrier 13507 has three sheets in P and one in K, but H. Perrier’s handwriting on specimen P00094557 clearly shows that it is the sheet sent to Berlin for the description by Schlechter, it can therefore be considered the holotype.

One specimen, Gautier LG 3656 in G (G00096571), has been added here for reference but with doubts. It has been identified as Benthamia nivea subsp. parviflora by P.J. Cribb but the collector’s notes say “yellow tepals”. A dissection shows no other difference to a small Benthamia nivea .

See also: Schlechter (1930: t.11 n°44), Perrier (1939: 33), Cribb & Hermans (2009: 50).

DESCRIPTION

Erect epiphytic herb, 11-40 cm tall. Tubers many, fusiform, villous, 3-7 cm long. Stem 1-3 mm in diameter, with the base covered by 1-2 sheaths, with 2-3 basal leaves and sometimes another one higher up. Leaves 2-4, elliptic-lanceolate, 5-14 × 2-3.5 cm, with apex acute. Rachis cylindrical or unilateral, with 10-65 flowers, 3-13 cm long. Floral bracts narrowly lanceolate, very acuminate, the lower ones longer than the flower,the upper ones as long as the ovary, 5.5-9 × 1.3-2.5 mm. Ovary 5-8 × 1.1- 1.8 mm.Flowers 5-10 mm long without the ovary, not opening widely, snow white, nicely scented according to collectors, all floral pieces forming a slightly curved tube (going down, then up) in the lower third of the flower; dorsal sepal linear-obtuse, slightly porrect, 4.3-8 × 0.6-1.3 mm, with narrowed base, 1-veined; lateral sepals a little wider, 5-8 × 0.7-1.2 mm; petals dissymmetric, slightly porrect, wider than sepals, 4-8.5 × 0.8- 1.8 mm, 3-4-veined in the lower 2/3rd, thickened higher up, obtuse; dorsal sepal and petals a little spreading but not ending in a single plane; lip narrowly oblong, 4.5-9 × 1.6-4 mm, the base a little concave, trilobed in about the upper third, with a very light longitudinal callus, 5-veined visible only at the base; lateral lobes thin, subacute, parallel to the midlobe when flattened, divergent in the fresh because folded, 1.4-2.5 mm long; midlobe wider and slightly longer, 1.7-3.5× 0.8-1.1 mm, obtuse and thickened, rounded or obscurely truncate; base of lip twice wider than midlobe; spur subglobose, saccate, 0.7-1.2 × 0.7- 1.5 mm.Column 0.6-1 × 0.4-1.1 mm; anther almost orbicular, with an obtuse nose-shaped apiculus; auricles falciform, narrow, as long as the anther or slightly longer; rostellum tridentate, sometimes with the midlobe longer.

Figures

FIG. 79. — Benthamia nivea Schltr., Antananarivo prov., Ambatolampy area, Hort.Malala Orchidées,2000.Cultivar Madagascan Dream BC/RHS 11/4/2000. Photograph by Johan Hermans.