Marsilea drummondii
common nardoo
Overview
Marsilea drummondii is an aquatic to amphibious fern that spreads by creeping rhizomes rooted in mud, sending up long stalks topped with four wedge-shaped leaflets that look like a four-leaf clover. The leaflets are 0.4-1 inch (10-25 mm) long, grey-green and often covered in soft hairs, and float on the water surface or stand above wet mud, with stalks 2-12 inches (5-30 cm) long depending on water depth. As pools dry, the plant forms hard, bean-like spore cases (sporocarps) at the leaf bases that survive years of drought and release spores when wetted again. It grows on floodplains, claypans, channels, and temporary wetlands across inland Australia, appearing quickly after flooding and dying back as the water recedes. The sporocarps are high in an enzyme called thiaminase, which breaks down vitamin B1, and eating unprocessed nardoo can cause severe thiamine deficiency in people and animals. The plant tolerates extreme wet-dry cycles but needs flooding to grow and spread, so it is absent from consistently dry sites and from deep, permanent water.
Native Range
Marsilea drummondii is native to inland Australia across all mainland states. It grows on floodplains, claypans, channels, and temporary wetlands that flood and dry in cycles.Suggested Uses
Marsilea drummondii is grown in ponds, bog gardens, and shallow water features and in wetland restoration on inland floodplains. Its clover-like floating leaves suit the margins of ornamental ponds and container water gardens.How to Identify
Appearance
Size & Dimensions
Height2" - 1'
Width/Spread1' - 4'
Reaches mature size in approximately 1 years
Colors
Foliage Colors
Fall Foliage Colors
Bloom Information
As a fern, Marsilea drummondii does not flower; it reproduces by spores held in hard cases at the leaf bases. New leaves appear quickly after flooding, mainly in the warmer months. Spore cases form as pools dry and can stay dormant for years until the next flood.
Detailed Descriptions
Foliage Description
grey-greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Marsilea drummondii grows in shallow water, on wet mud, and in pond margins in full sun, spreading by rhizomes once it has standing water or saturated soil. It tolerates being dried out, surviving as rhizomes and spore cases through drought and regrowing when flooded again. In cultivation it is grown in pots standing in water or in the shallows of ponds, in a heavy loam or clay mix. It withstands heat and light frost in USDA zones 9-11. Growth is fast in warm, flooded conditions and stops as water dries up. The spore cases contain thiaminase and are not safe to eat unprocessed.Pruning
Thinning crowded leaves and rhizomes keeps the plant within its pot or pond zone, as it spreads readily in shallow water. Old leaves die back as water recedes and can be cleared then. The plant regrows from rhizomes after cutting back.Container Growing
✓ Suitable for container growing
Minimum container size: 3 gallons