When Puya berteroniana, a bromeliad related to the Pineapple, sends up its flower stalk, it commands attention. The stalk, well over eight feet high, is covered with brilliant turquoise blossoms centered with contrasting orange anthers making it a magnet for nectar-sipping birds, bees, and butterflies. Native to the Chilean coastal range, Puya berteroniana is also known as Turquoise puya flame, blue puya, and as chagual by local Chileans.
Puya’s long, narrow leaves are rimmed with fishhook-shaped defensive spines. These may prevent small animals from eating the plant but also can ensnare them thus providing nutrients for the plant from the decomposing bodies.
Last week, Tom Sauceda, Botanical Curator in charge of the New Zealand collection at the Arboretum, took a small group to visit the Puya specimens. Sauceda frequently visits Chile on botanical expeditions and described a hillside of Puya berteroniana growing behind a relative’s house. “Many of the plants were surrounded by charred remains and blackened ground,” he said. “It’s believed that Puyas spontaneously combust under certain conditions,” though the phenomenon has not been studied scientifically. Sauceda said the flame is most likely “blue fire” and unlikely to spread to other plants.
Sauceda does not recommend Puya for the home garden because it requires about seven years of growth before flowering, it is slow-growing, and the spines are very sharp so not gardener friendly. However, he says, “Puya is a wonderful plant for a big estate garden with lots of sunshine. It’s deer resistant, drought tolerant, and the flowers are stunningly beautiful.” Puya is hardy in zones 8b-11 and can survive temperatures down to 18-20 degrees.
The Arboretum has four Puya plants, which can be found in the old Chilean garden along the Elvander Taxonomy Trail near the gate to the New Zealand collection. Two are blooming currently.
For more information about what’s blooming at the gardens, see http://arboretum.ucsc.edu/visit/whats-blooming/index.html