Voyria bicolor H.Maas & O.Lachenaud, 2022

Gomes, Sofia I. F., Kikuchi, Izai A. B. S., Lachenaud, Olivier, Perdomo, Julian, Léotard, Guillaume, Maas, Paul J. M., Kamer, Hiltje Maas-van de & Merckx, Vincent S. F. T., 2022, Unravelling the species diversity, phylogeny and biogeography of the mycoheterotrophic Voyrieae (Gentianaceae) and the description of a new species, TAXON 71 (5), pp. 1013-1024 : 1017-1018

Voyria bicolor H.Maas & O.Lachenaud , sp. nov.

– Holotype: FRENCH GUIANA. Mont Chauve, forest on slope on well-drained soil , alt. 200 m, 03°49′N 52°44′W, 15 Apr 1997, Cremers & Crozier 14977 (CAY barcode CAY 030019 ! ; isotypes: P barcode P04014766 !, U barcode U. 0146830 !) .

The new species is illustrated in Fig. 4 .

Diagnosis. – Voyria bicolor comes close to the largeflowered V. clavata , but is immediately recognized by its 2-colored flowers (white and blue). Moreover, the calyx lobes of V. bicolor are longer than the calyx tube, while they are shorter than the calyx tube in V. clavata .

Description. – Mycoheterotrophic herb, to c. 20 cm high; stems simple to branched, whitish, internodes to 12(–40) mm long; roots not collected. Leaves whitish, narrowly triangular, 5–11 × 1.5–3 mm. Inflorescence 1- or 2(–9)-flowered. Flowers 5-merous; pedicels 4–10 mm long; calyx very pale brown, tube up to 3–4 mm long; lobes narrowly triangular to linear, 15–20 × 1–2 mm, apex acute, sinuses acute; corolla white with bright blue to/or violet center, funnel-shaped, 60–77 mm long; tube 50–65 mm long, longitudinally ribbed, 2–3 mm in diam. at the base, the upper part (10–13 mm) widened to 5–10 mm in diam. and bright blue; corolla lobes triangular, 9–12 × 4– 5 mm, apex obtuse; stamens inserted 10–12 mm below the throat, at the level where the tube starts widening, filaments 10–11 mm long, rather densely covered with erect hairs at the base, anthers yellowish white to dark yellow, basifixed, 2–3 mm long; ovary fusiform, c. 8 × 2 mm, basally glandular; style 50–65 mm long, stigma white, capitate. Capsule not seen.

Distribution and ecology. – Only known from northern French Guiana, in the Approuague and Sinnamary River basins; lowland evergreen forest on slope, up to 200 m in elevation. The species is evidently rare, having been collected only four times in spite of its highly conspicuous flowers.

Phenology. – Flowers in March, April and August.

Specimens studied. – FRENCH GUIANA. Mont Chauve , alt. 200 m, forest on slope on well-drained soil , 15 Apr 1997, 03°49′N 52°44′W, Cremers & Crozier 14977 ( CAY, P, U). Lowland trail to Roche Virginie , alt. 40 m, 2 Aug 2014, in the understory of primary rainforest , 04°11′51.2″N 52°08′ 10.3″W, Gomes & Merckx 62 ( L, spirit collection and photos only). Dropping Zone of Saut Aïmara, basin of Sinnamary River , 22 Mar 1991, 04°38′N 52°55′W, Hoff 7008 ( CAY). In sylvis montosis Matouri , Jun 1837 (locality and date uncertain, see notes below), Leprieur s.n. ( P [ P00506654 ], mixed with V. clavata ) .

Notes. – Voyria bicolor closely resembles V. clavata in the shape and dimensions of its flowers, but is easily distinguished by the bright blue to violet inner side of corolla throat. The two species also differ in the proportions of their calyx: in V. bicolor , the calyx lobes are much longer than the tube, while in V. clavata they are shorter than the tube ( Fig. 4C ).

The earliest collection of the species, Leprieur s.n., is a mixture of Voyria bicolor and V. clavata . The collector’ s notes, “in sylvis montosis Matouri [Matoury, near Cayenne] ad radices j palmarum. Juni 1837 j floribus aurantiacis”, probably refer to V. clavata , which usually has the corolla tube washed with orange outside. It is not clear if the material of V. bicolor was collected in the same place on the same date, or if two different collections got mixed under the same label. Leprieur is known to have travelled widely across French Guiana.

Figures

Fig. 4. Habit of Voyria bicolor (Gomes & Merckx 62, L). Photos: V. Merckx. Scale bars: 1 cm.