Dianella – Australia in the Andes?
We were descending into El valle Huaylla Belén (Amazonas District), high in the Peruvian Andes near the border with Ecuador. Looking up (one of only two directions in the Andes), I saw a plant that made me think I was back in Australia (a mere 13,500 km across the Pacific Ocean). I could have sworn I was looking at a Dianella.
Later identified as Eccremis coarctata, the plants are almost indistinguishable from Australian Dianella. A single species of Eccremis is known, native to the Andes in northern Peru, Ecuador and Venezuela. Eccremis grows at high altitude, on misty slopes.
A molecular phylogeny of the family has found that Eccremis is sister to the genus Dianella. It probably reached South America by long-distance dispersal early on in the evolution of the Dianella clade (Wurdack & Dorr 2009).
Eccremis joins other plant groups with direct links to Australian species, including Orthrosanthus and Libertia (Iridaceae), Oreocallis (Proteaceae) and Boerhavia (Nyctaginaceae).
Dianella, a genus of over 40 species, is concentrated in southern Australia. A small number of Dianella species extend from Africa through south-east Asia to the Pacific Islands and New Zealand. In Australia, Dianella species are common in many bushland settings. They are popular in horticulture for their hardy foliage and attractive flowers.
Lily-like plants, now generally classified in the Hemerocallidaceae, Dianella and Eccremis have pendant blue flowers that are buzz-pollinated, similar to many Solanum species (tomatoes and potatoes). Bees buzz their wings at a specific frequency that shakes the pollen loose for the hovering bee to collect.
Solanum orbiculatum, from Australia, is shown on the right - with a rather uncanny resemblance to the Dianella species illustrated above.