Periwinkle Periwinkle is also called vinca or myrtle. Of the 12 species of periwinkle, two are popular ground- covers.
All species have opposite leaves and single flowers.
Oblong to ovate leaves are opposite, simple, to 2 inches long, glossy, with a short petiole. They exude a milky juice when broken. Flowers are purple, blue or white depending on the cultivar. Plants bloom in April and sometimes again in the fall. Vinca minor grows about 6 inches tall, spreading in all directions by sending out long trailing and rooting shoots, which make new plants.