Scientific Name: Hydrocotyle ranunculoides
Common Names: Floating Marshpennywort, Floating Marsh-pennywort, Water-pennywort, Floating Pennywort, Floating Pennyroyal
Growth Habit: Herb/Forb
Arizona Native Status: Native
Habitat: Riparian. This freshwater aquatic plant grows along lake edges and in ponds and wetlands. These plants were photographed in the Arivaca Cienega, a desert wetland in the Buenos Aires National Wildlife Refuge.
Flower Color: Inconspicuous (greenish to yellowish white, purplish)
Flowering Season: Late spring, Summer
Height: Up to 16 inches (40 cm) above the water surface and as much or more below
Description: The tiny flowers are in small, dense, single umbels below the leaves. The flowers are followed by dry, 2-seeded fruits that split in half when mature. The leaves have 3 to 7 deep lobes, smooth or scalloped margins, and are shiny, dark green, hairless, and rounded to kidney-shaped. The leaves have a deep cleft from the edge of the leaf to where the leaf stalk attaches, so they are not peltate unlike some other Hydrocotyle species. The stems root at the nodes and are fleshy, hairless, ribbed, hollow, and floating or creeping. The roots are dense and hairlike. The plants can form broad, dense mats of vegetation on the surface of the water.
The similar Whorled Marshpennywort (Hydrocotyle prolifera) and Whorled Marsh Pennywort (Hydrocotyle verticillata) have proliferating flower spikes with stacked whorls (not a single umbel) and their leaves are peltate and not deeply lobed.
Kingdom: Plantae – Plants
Subkingdom: Tracheobionta – Vascular plants
Superdivision: Spermatophyta – Seed plants
Division: Magnoliophyta – Flowering plants
Class: Magnoliopsida – Dicotyledons
Family: Apiaceae – Carrot family
Genus: Hydrocotyle L. – hydrocotyle
Species: Hydrocotyle ranunculoides L. f. – floating marshpennywort
More About This Plant