O. lutea ssp quarterae was first described from the Algarve, Portugal by Kreutz, Lowe and Wucherpfennig in 2007, although it had been known for many years from a small number of sites that were then thought to be outlying populations of O. sicula or possibly even O. battandieri, otherwise from the Tell Atlas of north Africa. Expert opinion differs as to whether this taxon should be classified as a full or sub species.
This taxon is rare and known from only two regions in the southern Iberian peninsula, the Algarve of Portugal and Andalucia in southern Spain. In the former area it is largely restricted to the valley of the Ribeira de Quarteira (from where it was first described and named) and in Andalucia in the Provinces of Cadiz, Sevilla, Jaen and Malaga.
It grows in relatively small colonies, very often in close association with O. lutea itself. It is however easily separated from this species by virtue of its slender appearance and smaller flower which invariably carries
an inverted "v" extension of the
brown central lip area into the yellow margin of the central lobe. This
latter feature is also a common characteristic
of O. sicula and one of the key reasons that O. lutea ssp quarterae was for long thought to be that species. It prefers an alkaline soil with conditions very similar to that of O. lutea and despite assertions that it flowers up to three weeks in advance of O. lutea, the authors have not found there to be a great deal of difference
between the two. This observation is however based on higher
altitude populations above 500m in the province of Malaga and the same
situation may not prevail elsewhere in its range.
The pictures come from the Grazalema region of Andalucia, Spain dating from the second week of April.
