Altensteinia schickendanzii, Schltr.

Aa schickendanzii Schltr. [as Aa ‘ schickendantzii ’ by Correa 1996 and Schinini et al. 2008], Repert. Spec. Nov. Regni Veg. 16: 438. 1920. [15 Jul 1920]. TYPE: ARGENTINA. [Catamarca]: ‘Alto de la Toma, Granadillas’, November 1873, F. Schickendanz 264 (lectotype: CORD00002205! designated here; isolectotypes: GOET008355!, SI092352!). Syn. nov.

Plants terrestrial. Roots fleshy, fasciculate, pubescent. Leaves basal, ovate–lanceolate, sub-erect, 6–9 3 0.6–1.2 cm. Inflorescence slender, erect, up to 32 cm long, glabrous, enclosed by broad, hyaline and diaphanous sheaths, terminated in a densely many flowered cylindrical spike of 5–7 cm long, rachis of the spike glabrous. Floral bracts deltoid to lanceolate, acute to obtuse, margin entire to slightly erose, concave, 4–5 3 4 mm, reflexed, somewhat surpassing the flowers. Flowers white, glabrous. Dorsal sepal ovate to lanceolate, obtuse, 1-nerved, reflexed, 1.7–2.0 3 1.3–1.5 mm. Lateral sepals shortly connate at the base, obliquely oblong-lanceolate, acute or slightly obtuse, entire, somewhat carinate, 1-nerved, 2–2.5 3 1–1.5 mm. Petals obliquely oblong-lanceolate, obtuse, 1-nerved, up to 2–2.3 3 0.8–1.1 mm. Lip cucullate, globose to ellipsoid, fleshy (except the margins), notably 3-lobed, margins involute, with moniliform hairs, 2.0–2.7 3 2.5–5 mm. Column short, emarginate, glabrous. Ovary sessile, ellipsoid, glabrous, 2–3 mm long.

Distribution and Habitat — Aa achalensis grows in Argentina (Catamarca, Córdoba, Jujuy, La Rioja, San Juan, and Tucumán Provinces) at 1500–3500 m a. s. l., in the grasslands of the Chaco Serrano and Yungas montane forest ( Sobral and Fracchia 2010). This species was placed into the Vulnerable category at the global level in the IUCN Red List Criteria ( Vischi et al. 2004), but the new taxonomic circumscription of Aa achalensis suggests that this status should be re-evaluated. Flowering and fruiting plants have been recorded from October to April.

Taxonomic Notes —This species differs from all other Argentinian Aa species by its glabrous reproductive and vegetative structures. In the protologue of Aa achalensis Schlechter (1920a: 358) cited ‘ Argentina: Sierra Achala de Córdoba, am Fusse des Cerro Champaqui, oberhalb des Rio de Latre — G. Hieronymus no. 796, am 27. Febr. 1877.’ This type specimen was housed in B, but it was destroyed in the Second World War (Dr. R. Vogt pers. comm.). We found two duplicates from Hieronymus´s collections housed in GOET and CORD whose labels have the same collection number and locality, but they differ on the date mentioned in the protologue, 27 Feb 1877 (vs. 29 Jan 1877).A neotype for the name Aa achalensis is necessary (cf. Art. 9.13–9.16, Turland et al. 2018). Therefore, we choose the sheet CORD00002203 as neotype.