Paspalum rawitscheri (Parodi) Chase ex G. H. Rua & Valls

Rua, Gabriel H. & Valls, José Francisco M., 2012, On the taxonomic status of the genus Thrasyopsis (Poaceae, Panicoideae, Paspaleae): new combinations in Paspalum, Phytotaxa 73 (1), pp. 60-66 : 63

Paspalum rawitscheri (Parodi) Chase ex G. H. Rua & Valls , comb. nov.

Basionym:— Thrasyopsis rawitscheri Parodi (1946: 294) . Type:— BRAZIL. Paraná: Estrada Ponta Grossa a Tibagi , em campos, 14 February 1945, Joly 17 (Holotype: BAA!) .

Synonym:— Thrasyopsis juergensii (Hack.) Soderstrom ex A. G. Burman (1980: 221) . Panicum juergensii Hackel (1915: 70) , ‘jürgensii’. Type:— BRAZIL. Rio Grande do Sul: Lagão, Município Soledade, in campis siccis, 1912, Jürgens G412 (Holotype: W; isotype: US [barcode] US 00148598 digital image!).

Cespitose perennials with erect culms. Leaf sheaths sheltered by stiff, deciduous hairs, leaf blades rigid, long attenuate towards the base. Racemes mostly solitary, or eventually paired, 10–15 cm long, with rachis broadly winged, foliaceous, partially covering the spikelets. Spikelets paired, glabrous, lower glumes 0–5-nerved, up to ½ the length of the spikelets, sometimes wanting; upper glumes obovate, 13–17-nerved, the apex truncate overtopped by the excurrent nerves; lower floret male, the lower lemma 7–9-nerved, glume-like; upper floret bisexual.

Distribution, habitat, and conservation status: ―Endemic to Southern Brazil, this relatively rare species occurs in ‘campos’ on outcropping areas in the states of Rio Grande do Sul, Santa Catarina and Paraná ( Burman 1983, Filgueiras 2012). The species was classified as ‘vulnerable’ ( Boldrini 2009) and included in the list of threatened species of the Brazilian flora, because of the progressive reduction of the already small number of surviving individuals in known populations ( Valls et al. 2009).

Additional specimens examined: ― Paspalum rawitscheri . BRAZIL. Rio Grande do Sul: Campestre da Serra , BR 116 , km 65, segunda curva a esquerda após a ponte sobre o rio Canabarro , baixada com pedras na borda do capão, à direita da estrada, elev. 774 m, 28º40’45”S, 51º03’54”W, 09 February 2006, Rua & Rosa 728 ( CEN)

Nomenclatural notes: ―Because of the previous existence of the name Paspalum juergensii Hackel (1909: 312 , ‘jürgensii’), referring to a different species, the combination resulting from the transference of Panicum juergensii Hackel to Paspalum would be a later homonym. Thus, the species must be called Paspalum rawitscheri based on the earliest available epithet ( McNeill et al. 2006, Art. 11.4). Such a combination has been formerly made by Chase (unpublished manuscript) but was never effectively published.