Slough thistle facts for kids

Cirsium crassicaule is a special type of thistle plant. It's often called the slough thistle. This plant is only found in a specific part of California, USA. It grows mostly in freshwater wetlands, which are like marshy, wet areas.

It has only been found in a few places within Kern, Kings, and San Joaquin Counties. This makes it quite unique to these areas.

What Does Slough Thistle Look Like?

The slough thistle can grow very tall, sometimes reaching up to 300 centimeters (about 10 feet)! That's taller than most people. Its stem is thick and hollow, sometimes almost 10 centimeters (4 inches) wide at the bottom. The stem is covered in soft hairs and a bit of a web-like fuzz.

Leaves and Spines

The leaves of the slough thistle are also quite interesting. They are woolly and spiny, and they are deeply cut into many different shapes, almost like puzzle pieces. These leaf sections often have small teeth along their edges. The longest leaves grow near the bottom of the plant and can be as long as 70 centimeters (28 inches).

Flowers and Life Cycle

The slough thistle is an annual or biennial plant. This means it either lives for one year (annual) or two years (biennial) to complete its life cycle.

How It Flowers

The plant produces clusters of several flower heads. Each flower head can be up to 3 centimeters long and 3 centimeters wide. Around the outside of each flower head are spiny leaf-like parts called phyllaries. Inside, you'll find many pale pink flowers, though sometimes they can be white.

Seeds and Fruit

After the flowers bloom, the plant produces fruit. The fruit is a type of seed called an achene. It has a flat, dark brown body that is about 5 millimeters long. On top of the achene is a feathery part called a pappus, which can be up to 2 centimeters long. This pappus helps the seeds float away in the wind, spreading them to new places.