Evotrochis verticillata

Perennial of the Primulaceae family, this species is native to the Arabian Peninsula and the Horn of Africa, where it grows in cliff crevices and shaded rocks, at altitudes exceeding 2,000 meters, notably in Yemen, Ethiopia, and Eritrea. Long known as Primula verticillata, it was recently transferred to the genus Evotrochis.

It forms a basal rosette of oval to spatulate leaves, light green to yellowish green, slightly farinose on some individuals, with crenate edges. The erect flowering stems, 20 to 40 cm tall, bear the flowers in superimposed whorls, a rare arrangement in the Primulaceae group, which is the most immediately distinctive feature of the species and gives it its epithet.

The flowers are bright yellow to sulfur yellow, tubular at the base with five spreading lobes, very similar in general appearance to cultivated primroses. In its natural habitat, its flowering extends from January to March. In cultivation, it generally blooms from February to April.

It requires well-drained, slightly calcareous soil, in a semi-shaded position and protected from excessive winter moisture. Its hardiness is limited, around -5°C, which necessitates in cold climates cultivation in a cold greenhouse or alpine house.