Chloris pycnothrix Trin. 1824

Chloris pycnothrix Trin. (1824: 234) Specimen examined: PORTUGAL. Santa Cruz, at drive in of Quinta Albatroz, lawn, roadside, several 100’s, also on the other side of the VR-1 motorway, 1 May 2022, F. Verloove 14372 (BR, MADM). This weed is distributed throughout the tropics in Africa and America and is frequently recorded outside its native distribution range as an introduction (Anderson 1974). In climatologically suitable areas, it is increasingly naturalizing. In the Mediterranean area, it is, at present, known from Egypt and Israel / Palestine (Euro+Med Plantbase 2023). In Macaronesia, it was recorded for the first time in La Palma (Canary Islands) in 2011 (Otto & Scholz 2012) and it has locally naturalized there, especially in banana plantations and lawns. In Cape Verde, in contrast, it is considered to be a native species (Arechavaleta et al. 2005). In the island of Madeira, Chloris pycnothrix was first found in May 2022. The species occurs in and near a lawn and along sidewalks and under crash barriers on both sides of the VR-1 motorway at the Cristiano Ronaldo International Airport, in Santa Cruz. It is most abundant in a lawn at the Quinta Albatroz and may initially have been introduced with lawn seed, whether or not intentionally. It is obviously spreading and a future, wider naturalization in the area is likely. Two further (alien) species of Chloris have previously been recorded from the island of Madeira, viz C. gayana Kunth and C. virgata Sw. (Press & Short 1994, Vieira 2002, Jardim & Sequeira 2008, Menezes de Sequeira et al. 2012, Muer et al. 2020). These three species are separated as follows (Anderson 1974, Landge & Shinde 2022): 1 Lowest lemma with a crown of long spreading hairs at apex ..................................................................................... Chloris virgata 1’ Lowest lemma without a crown of long spreading hairs at apex .......................................................................................................2 2 Annual, usually geniculately ascending and rooting at the nodes. Leaf blade obtuse at apex. Spikelets 2-flowered, the sterile floret greatly reduced .............................................................................................................................................................. C. pycnothrix 2’ Perennial, usually erect. Leaf blade acute or tapering at apex. Spikelets 3–4-flowered, the sterile floret(s) well developed ............. ............................................................................................................................................................................................. C. gayana