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Algal Leaf Spot or Cephaleuros

Algal leaf spot. Photo: Dr. W. Nishijima

Photo:  Dr. Wayne Nishijima

Problem

Spots appear on the leaves.  Fruit of guava may also be affected. Algal leaf spot affects avocado, guava, pepper, magnolia, kava, tea, coffee, oil palm, vanilla, mango, breadfruit, and cacao.  Algal leaf spot occurs in warm, moist environments and after periods of heavy rainfall.

Avocado algal leaf spot. Photo: Dr. Scot Nelson

Algal leaf spot on Avocado
Photo: Dr. Scot C. Nelson, CTAHR

Description

Algal leaf spot or Cephaleuros  is a plant-parasitic green algae and is generally harmless though unsightly. Some Cephaleuros occurs on the upper leaf surface and is characterized by a raised, velvety, orange or brown appearance. Algal leaf spot can cause full necrosis of the leaf tissue, leaving brown dead spots. It can also appear as bright orange spots on the underside of the leaves. On some guava trees, a yellow halo encircles the lesions.

Information

Kendal Lyon, Hawaii Island Master Gardeners