Habenaria minuticalcar J. A. N. Bat. & Bianch, sp. nov.
Creators: name: Batista, João A. N.
name: Cruz-Lustre, Gabriela
name: do Vale, Aline A.
name: Bianchetti, Luciano B.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Asparagales
Orchidaceae
Habenaria
Habenaria minuticalcar

description: Habenaria minuticalcar J.A.N.Bat. & Bianch. sp. nov.
urn:lsid:ipni.org:names:77325126-1
Figs 3A–E, 4
Diagnosis
Similar to H.guilleminii Rchb. f. in the short spur, but distinguished by the leaves linear, narrow, 2–3 mm wide (vs lanceolate or lance-ovate, 5–23 mm wide), pedicellate ovary 7–12 mm long (vs 5–7 mm long), lateral sepals linear, 0.9–1.2 mm wide (vsobliquely ovate or obliquely lance-ovate, 2–3 mm wide), petal anterior segment filiform, 1.5–2.2 mm long. (vsreduced to a tooth-like projection, 0.2–0.7 mm long), and lip lateral segments shorter than the median segment (vslonger).
Etymology
From the Latin ‘minutus’ (very small) and ‘calcar’ (spur), referring to the very small spur, an unusual feature in the genus and one of the smallest among New World Habenaria.
Material examined
Holotype BRAZIL – Goiás • Alto Paraíso de Goiás, 21 km N. de Alto Paraíso, campo a margem esquerda da GO-118, em direção a Teresina de Goiás; Parque Nacional da Chapada dos Veadeiros; 1 Jan. 1999; fl.; J.A.N. Batista 843; GenBank nrITS: HM777691; nrETS: OP589155; matK gene and trnK intron: OP589167; rps16-trnK intergenic spacer: OP589998; holotype: CEN [32585].
Paratypes
BRAZIL – Goiás • Teresina de Goiás, Chapada dos Veadeiros, GO-118, em direção a Alto Paraíso, ca de 37 km ao N e antes de Alto Paraíso; 9 Jan. 2001; fl.; J.A.N. Batista & E.R. Pansarin 1149; CEN [CEN00037136] • Alto Paraíso de Goiás, Chapada dos Veadeiros; 30 Dec. 2010; fl.; J.A.N. Batista & L.B. Bianchetti 3099; BHCB [151375] • Alto Paraíso de Goiás, Chapada dos Veadeiros; 30 Dec. 2010; fl.; J.A.N. Batista & L.B. Bianchetti 3104; BHCB [151377] • Alto Paraíso de Goiás, estrada para a Vila de São Jorge, ca 26, 5 km da GO-118; 23 Jan. 2005; fl.; J. Paula-Souza et al. 4528; ESA [090123].
Description
Geophytic herb, caulescent, sympodial. Rootsand tuberoid not examined. Stem 13–28 cm long including the inflorescence, 0.8–1.2 mm wide, slender, erect, straight to somewhat sinouse. Leaves 5–8, spirallyalternate, linear, narrow, the largest concentrated in the middle of the stem, 1.5–8 × 0.2–0.3 cm, reducing towards the apex of the stem, base sheathing, sheath closed. Inflorescence 2–6 cm long, spiral, few flowered, lax; floral bracts 5–17 × 3–4 mm, elliptical, caudate, apex acuminate, about the same size as the pedicellate ovary, decreasing in size towards the inflorescence apex, green. Flowers 2–7, resupinate, green; pedicellate ovary 7–12 mm long, mostly straight, more or less parallel to the rachis axis or ascending, apex curved; ovary 6–10 mm long, pedicel 1–2 mm long. Sepals green, margin smooth, apex discreetly mucronate or obtuse; dorsal sepal 3–5 × 3–3.5 mm, concave, ovate or elliptical when flattened; lateral sepals 3–4.5 × 0.9–1.2 mm, obliquely linear to obliquely linear-lanceolate, deflexed or reflexed, apex obtuse. Corolla base whitish, towards the apex light green or greenish yellow. Petals bipartite; posterior segment 2.5–4.2 × 1–1.2 mm, oblong, slightly falcate, apex obtuse, connivent with the dorsal sepal; anterior segment 1.5–2.2 mm long, shorter than the posterior lobe, linear-filiform, inserted at the base of the posterior segment. Lip tripartite; undivided basal part 0.5 mm long; lateral segments 1.9–3 mm long, shorter than the median segment, linear-filiform, bent forward; median segment 3–4.5 × 0.7–0.9 mm, linear, bent forward; spur 1–1.6 × 1–1.3 mm, shorter than the pedicellate ovary, free from the bract, ovate, green. Gynostemium 1.5 mm high, reclinate; connective green, apex emarginate; lateral appendages (auricles) 0.9–1.2 × 0.4 mm, fleshy, verrucose, apex obtuse, whitish. Anther 0.7– 1 mm high, bilocular, loculi parallel, translucent; canals very short, slightly convergent; pollinaria 2, 0.7–0.8 mm long each, joined by the viscidia; caudicles 0.2 mm long, filiform; pollinia 0.5–0.6 mm long, yellow; viscidia 0.15 × 0.15 mm, enclosed between the anthers. Stigmatophores (stigma lobes) 2, ca 1.6 mm long, closely parallel, green, receptive surface 0.9 mm long, convex, turned frontwards, 0.4 mm wide each, apex obtuse. Rostellum ca 1 mm long, green; mid lobe ca 0.6 mm long, 0.4–0.5 mm high, triangular, erect, held between the anther loculi, fleshy, apex obtuse; side-lobes 0.3–0.4 mm long, convergent towards the apex.
Distribution, Habitat and Phenology
Habenaria minuticalcar sp. nov. is restricted to Chapada dos Veadeiros, State of Goiás, central Brazil. The new species grows in seasonally humid grassland (Fig. 3A), associated with ‘murundus’ or ‘campos rupestres’ (rocky fields), with dark, shallow, rocky, sandy-clay soils, at 1,100 to 1,600 m a.s.l. The soil can be humid during some periods in the rainy season (Fig. 3B) but usually dries out completely during the dry season. The plants are difficult to find in their habitat as they are small and slender, grow among grasses and can only be found when they are in flower. Flowering occurs during the peak of the rainy season, from December to January. Like other Habenaria and terrestrial grassland orchids, the flowering of the new species is enhanced by seasonal brush fires. All our collections of the species were made in areas burned from the previous dry season.
Conservation Assessment
Habenaria minuticalcar sp. nov. is currently known from only four populations, all from Chapada dos Veadeiros, and shows an EOO estimated at 194 km 2 and a small AOO of 16 km 2. Based on the IUCN Red List Categories and Criteria and its guidelines (IUCN 2012, 2016), the species can be tentatively classified as Endangered EN B1ab(iii)+2ab(iii); C2a(i).
Taxonomic notes
Habenaria minuticalcar sp. nov. resembles H. guilleminii in the size and morphology of the spur. However, it is distinguished by the linear, narrow, 2–3 mm wide leaves (Fig. 4D–F) (vs lanceolate or elliptical, 5–23 mm wide in H. guilleminii), narrow, 0.9–1.2 mm wide lateral sepals (vs 2–3 mm wide), petal anterior segment 1.5–2.2 mm long, reaching half the size of the petal posterior segment (vs reduced to a tooth-like projection) and lip lateral segments at most half the length of the median segment (Fig. 4G–I) (vs lateral segments longer than the median segment). Habenaria minuticalcar sp. nov. is also similar to H. pansarinii var. minuscula J.A.N.Bat. & Bianch. in general morphology and size of the spur. However, it differs from this taxon by the floral bract measuring 5–17 mm long, approximately the same length as the pedicellate ovary (Fig. 4J–K) (vs 2.2–3.5 mm long, shorter than the pedicellate ovary), the slightly larger flowers (e.g., dorsal sepal 3–5 × 3–3.5 mm vs 2.4–3 × 1.8– 2.4 mm in H. pansarinii var. minuscula), the petal posterior segment 2.5–4.2 mm long, oblong with an obtuse apex (vs 2.1–2.7 mm long, lanceolate, apex acute), and the geographical distribution restricted to Chapada dos Veadeiros (vs restricted to the southern and central regions of the Espinhaço Range in the State of Minas Gerais).
description: Published as part of Batista, João A. N., Cruz-Lustre, Gabriela, do Vale, Aline A. & Bianchetti, Luciano B., 2023, Checklist and molecular phylogenetics reveal three taxonomic novelties in Habenaria (Orchidaceae, Orchidoideae) from Chapada dos Veadeiros, Goiás, Brazil, pp. 51-86 in European Journal of Taxonomy 891 on pages 60-62, DOI: 10.5852/ejt.2023.891.2271, http://zenodo.org/record/8368306