Setaria P. Beauv. (1812: 51)

Verloove, Filip, Gonçalves Silva, Juan J. & Leliaert, Frederik, 2024, Critical notes on grasses (Poaceae) of Madeira, Portugal, Phytotaxa 670 (1), pp. 1-17 : 11

Setaria P. Beauv. (1812: 51)

Setaria adhaerens (Forssk.) Chiov. is the warm-temperate/subtropical counterpart of S. verticillata (L.) P. Beauv. Both have spikelets with clinging, retrorsely barbed bristles in common but S. adhaerens differs due to its leaf sheath margins that are perfectly smooth (vs. long ciliate). In Macaronesia, like in other regions with a subtropical climate, it is the usual weed of the two. In Cape Verde, for instance, only S. adhaerens is known ( Arechavaleta et al. 2005). Yet, only S. verticillata was mentioned from Madeira in a recent checklist, whereas both were cited from the Azores ( Jardim & Sequeira 2008, Menezes de Sequeira et al. 2012). It is very unlikely that S. adhaerens is indeed a recent introduction in the island of Madeira: it was already collected there in 1900 by Bornmüller (Funchal, in incultis, Aug. 1900, J. Bornmüller n° 1313 Plantae exsiccatae Maderenses; BR!). More plausible is that these species have been confused so far in the island of Madeira or considered to be conspecific (see also Vieira 2002), erroneously so. In a recent monograph of Setaria in the Old World ( Morrone et al. 2014) both were accepted as distinct species (see also Rominger 2003 and other contemporary floras).

Specimen examined: PORTUGAL. Machico, cemetery, as a weed, very common everywhere, apparently confused with S. verticillata , 11 September 2021, F. Verloove 14120 (BR).