Water Pennywort

Hydrocotyle umbellataWater pennywort mass

Family:
Apiaceae

Lifecycle:
Perennial

Native or Introduced:
Native

Nutrient Removal Rating:
Low

Wildlife Value:
Lowpicture of water pennywort

Invasiveness:
Medium

Rooted or Floating:
Floating

Site Requirements:
Full sun

Maximum Water Depth:
n/a

Plant Description:
Water pennywort is an herbaceous perennial. It produces tangled, air-filled-horizontal stems that root at the nodes. Stems are round and light green to cream in color. This plant forms large colonies of mat-like growth.

Leaves develop directly from horizontal stems; petioles measure 6-12 inches in length. Petioles attach to the center of the leaf blades. Blades are rounded with heavily notched margins. Veins radiate from the point of petiole attachment. Leaf blades measure 1-2 inches across.

Flowers are small, light green, and star shaped. Flowering stalks terminate in umbels (0.5 inch diameter) of 5-13 flowers.

Water pennywort is found in marshes, at the edges of lakes or ponds, and in muddy soils.

Water pennywort can be distinguished from floating pennywort by differences in leaf characteristics. Floating pennywort has pink disks at the location of petiole attachment while water pennywort has light green disks at the same location.

Sources:

  • Audlbach-Smith, C.A., deKozlowski, S.J. 1996. Aquatic and Wetland Plants of South Carolina. South Carolina Department of Natural Resources.
  • Flora of North America (see link below)

Additional reading:picture of water pennywort