Woolly Marbles

Common name: Woolly Marbles

Scientific name: Psilocarphus brevissimus
Family: Asteraceae (sunflower)
Habitat: vernal pools
Size: plant up to 4 inches tall, each “marble” 1 to 2 cm across

Fun facts: Each fuzzy “marble” contains both leaves and flowers.

Description: Member of the sunflower family. Each flowerhead is made up of 20 or more disk flowers. These are well hidden in the cob-webby fuzz. The plants are pale green.

The top photo shows the plants early in the season. The flowerheads are visible in the center of the leaves. The bottom photo is later in the season when the leaves curl up.

Life cycle: Woolly Marbles are annual plants. They germinate as the vernal pool water warms and begins to evaporate in the spring. Once the water is gone, they grow quickly. Woolly Marbles can be seen from late April until the rains begin in the fall. The flowers are well hidden in the fuzz. They bloom in May.

Ecology: Woolly Marbles are endemic to vernal pools. Endemic means they cannot grow in other environments because they are either too dry or too wet. The plants do not release their seeds until the rains come in the fall. This prevents them from blowing away into unsuitable habitats.

Woolly Marbles are able to grow in vernal pools long after many other vernal pool plants have dried up. Their fuzz keeps the dry air from touching the plant and stealing its moisture.

Investigate: The individual flowers are very well hidden in the cob-webby fuzz of the plant. See if you can find the disk flowers in the Woolly Marbles by using your hand