Rock spider orchid facts for kids

The Caladenia petrensis, also known as the rock spider orchid, is a special type of plant from the orchid family. It grows only in the south-west part of Western Australia, which means it is endemic to that area. This orchid has one tall, hairy leaf and can grow up to three pale yellow flowers. Its flowers have sepals and petals that hang down, making them look a bit like a spider.

What Does the Rock Spider Orchid Look Like?

The rock spider orchid is a terrestrial plant, meaning it grows in the ground. It's also a perennial herb, which means it lives for more than two years and its leaves die back each year, but it grows back from an underground storage part called a tuber. You might find it growing by itself or in small groups.

• Leaves: Each plant has one upright, hairy leaf. It's about 60 to 110 millimeters (2.4 to 4.3 inches) long and 3 to 6 millimeters (0.1 to 0.2 inches) wide. Near the bottom, the leaf often has reddish-purple spots.

• Flowers: The rock spider orchid can have up to three flowers on a stem that stands about 17 to 37 centimeters (6.7 to 14.6 inches) tall. These flowers are quite large, measuring 90 to 150 millimeters (3.5 to 5.9 inches) long and 80 to 140 millimeters (3.1 to 5.5 inches) wide. They are usually cream or pale yellow with dark red lines and blotches.

• Sepals and Petals: The top part of the flower, called the dorsal sepal, stands up straight and curves a little forward. The side sepals and petals spread out wide but have tips that droop down. These tips are dark brown and covered in tiny hairs.

• Labellum: The labellum is a special lip-like part of the orchid flower. On the rock spider orchid, it's pale yellowish-white with red stripes. It has jagged edges that face forward, and its tip curves downwards. There are also two rows of anvil-shaped bumps, called calli, along its center.

This orchid usually blooms from late July to September.

How Did It Get Its Name?

The rock spider orchid, Caladenia petrensis, was officially described in 2007 by two scientists, Andrew Brown and Garry Brockman. They found a specimen near a place called Rothsay. The second part of its scientific name, petrensis, comes from a Latin word that means "among rocks." This name fits perfectly because this orchid loves to grow in rocky areas!

Where Does the Rock Spider Orchid Live?

You can find the rock spider orchid growing between the towns of Canna and Paynes Find in Western Australia. It prefers to grow in soils that get wet during certain times of the year, especially on rocky hills.

Is the Rock Spider Orchid Protected?

Good news! The Western Australian Government's Department of Parks and Wildlife has classified Caladenia petrensis as "not threatened." This means that, for now, it's not in danger of disappearing.