Casuarina equisetifolia
horsetail tree

Casuarinaceae (casuarina family)
Northern Australia, Indonesia

Horsetail casuarinas have been widely planted on tropical beaches around the world (for example in Florida and the Caribbean, where they are known as pinos australianos) because of their ability to grow in sand and withstand wind and salt. They can reach over 100 feet. The segments on the needle-like branchlets are ¼ inch long, and the number of leaf teeth is commonly seven. The cone-like fruit are about ½ inch long and tend to have about eight bivalves in each tier. The outside surface of the valves is furry as seen with a lens. Casuarinas are being bred for desert reclamation in Egypt and are said to be the best fuel wood in the world, giving off mainly heat and CO2 and very little ash or smoke. The dense, dark wood was used for fueling locomotives before oil arrived.

Many specimens were raised from seed from Stanford trees in the old nursery on Serra Street just north of the Fire Station. Groups of horsetail tree may be found to the west of Lasuen Street between Campus Drive East and El Camino Real.

C. equisetifolia are monoecious plants, with male and female flowers produced on the same tree, so when you find a campus Casuarina bearing both staminate and pistillate flowers, it’s likely C. equisetifolia. Other Casuarina are dioecious, having separate male and female plants.

Related Material: Field Guide to Identify the Common Casuarina (Australian Pine) Species in Florida by William S. Castle offers excellent field identification advice.

About this Entry: The main text of this entry is from the book Trees of Stanford and Environs, by Ronald Bracewell, published 2005. John Rawlings removed a reference to a male specimen north of the Faculty Club dining room, and noted the monoecy of this species. First mentions of cones and needles changed to cone-like fruit and needle-like branchlets Jan 2018 (SP).