Basionym: Holcus redolens Vahl (1791: 102).
Type:— ARGENTINA. Tierra del Fuego, Antártida e Islas del Atlántico Sur: Habitat in Tierra del Fuego. Vahl (1791) (holotype: C10017002 digital image!).
Homotypic names: Avena redolens (Vahl) Persoon (1805: 100), Torresia redolens (Vahl) Roemer & Schultes (1817: 516), Hierochloe antarctica var. redolens (Vahl) Brongniart (1829 [1833]: 144), Anthoxanthum redolens (Vahl) P. Royen (1979: 1185).
Description: Stems (25)40–200(300) cm. Robust, 3–5 nodes.Ligules triangular or obtuse.Leaf-blades flat or convolute, glabrous, pubescent, scaberulous or scabrous; apex acuminate. Panicle spiciform, slightly contracted or open, linear or lanceolate, interrupted or not, narrowing to the apex. Rhachis glabrous, pubescent, scaberulous or scabrous. Spikelets 5–14 mm long, usually cuneate or, in some species, oblong, without rhachilla extension. Glumes lanceolate or ovate, 1-keeled, 1- or 3-veined, with apex acute or obtuse. Glumes shorter, equal or larger than the florets. Lemma of male florets, membranaceous or papyraceous, 5-veined, awned, with awns apically or subapically inserted. Lemma of apical female floret ovate, unkeeled, 5-veined; muticous, mucronated or awned.
Leaf anatomy: Leaf surface with long cells type I3 and short cells S5. Stomata in the adaxial or in both surfaces. Hooks sometimes present but usually scarce. Cilia absent. Bulliform cells present or absent. Leaf section open, with quadrangular ribs or alternate quadrangular and triangular ribs. Median vascular bundle sheath complete and midrib not differentiated. Subepidermal sclerenchyma discontinuous adaxially and continuous or discontinuous abaxially, concurring with the vascular bundles.
Genome size and DNA-ploidy levels: 2C = 13.28 pg, 4 x (one specimen of H. redolens var. spicata); 2C = 16.89–20.42 pg, 6 x, and 2C = 27.04–27.43 pg, 12 x (three specimens of H. redolens var. altissima).
Habitat: Sandy soils in coastal areas and riverbanks and wet meadows, 0–3850 m a.s.l. (De Paula 1975, Sede 2012).
Distribution: Disjunct distribution in South America: from Venezuela to Peru and from central Chile and Argentina to Falkland Islands. Tropical-alpine at low latitudes (De Paula 1975, Sede 2012). Populations from SE Asia, Australia and New Zealand, traditionally included in H. redolens, are clearly differentiated using plastid and nuclear DNA markers (Pimentel et al. 2013) and are, therefore, not considered here. We agree with De Paula (1975) that the name H. redolens should be restricted to South American populations of the species.