Gratiola amphiantha D.Estes & R.L.Small

Habitat and Growth Environment

Gratiola amphiantha is a small aquatic plant that grows in non-Mediterranean climate vernal pools, which sometimes form in granite outcrop habitats.

Plant Type and Size

It is a delicate annual herb that reaches only a few centimeters in length.

Submerged Stem and Leaves

It has a short, threadlike stem surrounded by a rosette of tiny, lance-shaped submerged leaves.

Floating Leaves

Above the submerged leaves sits a pair of slightly larger, oval-shaped floating leaves that can grow up to 8 millimeters (0.3 inches) long.

Flower Placement

Flowers grow from the leaf axils of both submerged and floating leaves.

Flower Characteristics

Underwater flowers are cleistogamous and never open, while open flowers that form on the water's surface have five-lobed white corollas that are a few millimeters long.

Growth Rate and Life Cycle

This is a fast-growing species; it germinates immediately when sufficient rain is available, and matures to flower in just 17 days.

Life Cycle Adaptation

Its quick life cycle is an adaptation to the very brief period that appropriate growing conditions are available in these pools.

Associated Plant Species

Very few other plants grow in the granite outcrop vernal pools where this species occurs, besides local endemic Isoetes species such as Isoetes piedmontana.