Hierochloe pusilla Hackel ex Dusén (1907: 4)

Lema-Suárez, Irene, Sahuquillo, Elvira & Pimentel, Manuel, 2021, A revision of Hierochloe sect. Monoecia (Anthoxanthinae, Pooideae, Poaceae), Phytotaxa 478 (1), pp. 92-104 : 95-96

1. Hierochloe pusilla Hackel ex Dusén (1907: 4) .

Type: — ARGENTINA. Santa Cruz. Lago San Martín , “Río Fosiles in consortio Bolacis glebariae”, 950 m a.s.l., 10 April 1905, P.K.H. Dusén 5999 (lectotype, here designated: S-R2929 digital image!, isolectotypes: W1916-0018309 digital image!, US 99925 digital image!, BAA00002099 digital image!).

Homotypic names: Anthoxanthum pusillum (Hackel ex Dusén) Veldkamp in Schouten & Veldkamp (1985: 349).

Description: Stems 4–10 cm. Leaf-sheaths pubescent, at least the upper ones. Ligules truncate, erose. Leaves 5–7, basal, growing from nodes separated by very short internodes. Leaf-blades 3.5–30 × 1.5–3.0 mm, flat or conduplicate, stiff, striate and pubescent adaxially, glabrous or scarcely pubescent abaxially. Panicle 7–20 × 3–10 mm, spiciform, oblong, bearing few ovate spikelets (4–5 mm long) attached to a glabrous rachis. Glumes ovate, 3-nerved, completely covering the florets. Lower glume 3–5 mm; upper glume 4–5 mm. Male florets 3.5–5 mm, mucronate, papyraceous, truncate or obtuse, muticous. Lemma of lower male floret elliptic, scaberulous, 1-keeled, 5-veined. Lemma of upper male floret oblong, scabrous. Lemma of apical female floret ovate, 3–3.5 mm, membranaceous, light brown, unkeeled, 5-veined.

Leaf anatomy: Long cells 170–290 μm, rough. Stomata in adaxial surface. Cilia present; hooks and bulliform cells absent. Leaf section open with 7–10 round ribs. Median vascular bundle sheath single (not complete), midrib clearly differentiated. Subepidermal sclerenchyma discontinuous, more abundant and adjacent to the median vascular bundle and the leaf margin ( Figure 1. A & E ).

Genome size and DNA-ploidy levels: 2C = 12.63–13.12 pg, 4 x.

Habitat: Damp meadows and wetlands, 100–1000 m a.s.l. ( De Paula 1975, Sede 2012).

Distribution: Southern tip of the Andes (Santa Cruz and Tierra del Fuego in Argentina, Magallanes and Chilean Antarctica Region in Chile; De Paula 1975, Sede 2012).

Phenology: January–April.

Specimens examined:— CHILE. Magallanes and Chilean Antarctica Region : Near Pali Aike N.P., Empetrum rubrum shrubland, 171 m a.s.l., S 52º 09.679’ W 69º 47.130’, 20 January 2014, E. Sahuquillo & M. Pimentel s.n. (SANT-73539) .

Observations: Only the collection locality and two images (general habit and spikelet) were included in the protologue of this species, but no information about the specimens used is provided. Different plants from the same collection by Dusén and with the same label are stored in S, W, US and BAA. All these materials should be considered syntypes [Article 7.11, Example (Ex.) 13 in Turland et al., 2018], since Dusén did not designate a holotype .

Parodi (1941) revised some plant materials sent from the Swedish Museum of Natural History Herbarium, but no typification was carried out. Subsequently, De Paula (1975) mentioned a clastotype from the Buenos Aires University Herbarium (BAA), which was probably the same specimen seen by Parodi [a syntype, since no holotype had been declared (Art. 9.10, Ex. 11 in Turland et al., 2018)]. Schouten & Veldkamp (1985) indicated the holotype is housed in the Stockholm Herbarium, but made no reference to any particular plant, whereas Sede (2012) referred to the specimen S-R-2929 stored in S as the holotype. Recently, Villalobos et al. (2019) designated another plant from the Hackel herbarium in Wien (W) as the holotype (W1916-0018309). Following Article 9.12 and recommendation 9A (1&2) in Turland et al. (2018), we believe that the specimen S-R-2929 must be considered as lectotype, designated (inadvertently, as holotype) by Schouten & Veldkamp (1985). The specimen in W is, therefore, an isolectotype.

Figures

FIGURE 1. Hierochloe sect. Monoecia micromorphology details.A–C. Leaf transverse section. A. H. pusilla, leaf transverse section open with round ribs. B. H. juncifolia, leaf transverse section closed with polygonal ribs. C. H. redolens var. altissima, leaf transverse section open with quadrangular ribs. D–F. Leaf epidermis. D. H. redolens var. gunckelii, adaxial epidermis with long cells type I3 and stomata. E. H. pusilla, leaf epidermis with long cells type I3 and short cells S5 (round). F. H. juncifolia, leaf epidermis with long cells type I3 and short cells S2 (ax shaped).