Observations on Azorella compacta (Umbelliferae), a Tropical Andean Cushion Plant

The compact, resinous, coral-like mounds of Azorella compacta, or yareta, live in the dry, cold climate of high-altitude southern Peru and are practically free of herbivores. Observations in two stands, at 3960 and 4500 m, showed that flowering, although variable, occurs all year, even on individual plants. Development from flower to ripe seed takes three to four months. Flowering and plant growth are concentrated on the east and north sides of plants, perhaps because of greater direct insolation. At an especially vigorous stand the standing crop was 11 kg/m2, and the growth rate was 1.4 mm/ yr. At this growth rate, many plants at this sitec would be about 850 years old, and occasional individuals could be as old as 3000 years.