T. fortunei is a species of fan palm, specifically known as the Chinese windmill palm for their origin in China and Japan, where they have been cultivated for thousands of years. T. fortunei are hardy and fairly common, especially in areas like southern California. Trachycarpus is a relatively unusual species, in that hermaphroditic flowers are rare, and most specimens of the palm have only male or female flowers. The difference between the flowers is clear, so distinguishing the two is a simple process.
Examine the flowers of the T. fortunei that you are sexing. T. fortunei blossoms in the spring, and the flowers will appear underneath the palm fronds.
Look for the colour of the flowers. If the flowers have a yellow hue, the plant is a male; if they are green, it is a female. These flowers are individually two to four millimetres across, but occur in bunches that can stretch up to a meter.
Look for the size of the flower if you suspect a rare hermaphroditic flower. These flowers will be almost exactly the same as the male flower, but slightly larger. They will also contain fully developed carpels, which are female reproductive organs in plants. The carpels will be lined with silvery fibres.
Improper care can delay or prevent the plant from blossoming and can make sexing the flowers difficult.