Chloris pycnothrix Trin. (1824: 234)

Verloove, Filip, Gonçalves Silva, Juan J. & Leliaert, Frederik, 2024, Critical notes on grasses (Poaceae) of Madeira, Portugal, Phytotaxa 670 (1), pp. 1-17 : 2-3

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