North America Native Plant

Prickly Hornwort

Botanical name: Ceratophyllum muricatum australe

USDA symbol: CEMUA

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Ceratophyllum australe Griseb. (CEAU4)  âš˜  Ceratophyllum cristatum Spruce ex K. Schum. (CECR3)  âš˜  Ceratophyllum demersum L. var. cristatum K. Schum. (CEDEC)  âš˜  Ceratophyllum floridanum Fassett (CEFL5)  âš˜  Ceratophyllum llerenae Fassett (CELL)  âš˜  Ceratophyllum submersum L. ssp. muricatum auct. non (Cham.) Wilmot-Dear (CESUM)   

Prickly Hornwort: A Native Aquatic Plant for Southern Waters If you’re looking to add native aquatic plants to your water garden or pond, you might have come across the prickly hornwort (Ceratophyllum muricatum australe). This lesser-known native plant brings a unique underwater presence to aquatic landscapes, though information about this ...

Prickly Hornwort: A Native Aquatic Plant for Southern Waters

If you’re looking to add native aquatic plants to your water garden or pond, you might have come across the prickly hornwort (Ceratophyllum muricatum australe). This lesser-known native plant brings a unique underwater presence to aquatic landscapes, though information about this specific subspecies can be surprisingly scarce.

What Is Prickly Hornwort?

Prickly hornwort is a perennial aquatic forb native to the southeastern United States. As a member of the hornwort family, it’s a submerged aquatic plant that lacks true roots, instead anchoring itself to the bottom of water bodies or floating freely. The plant gets its prickly name from its finely divided, somewhat spiny-looking foliage that creates an intricate underwater texture.

This plant is also known by several scientific synonyms, including Ceratophyllum australe, Ceratophyllum cristatum, and Ceratophyllum floridanum, which can make identifying and sourcing this specific variety a bit of a botanical treasure hunt.

Where Does It Grow Naturally?

Prickly hornwort is native to a limited range in the southeastern United States, naturally occurring in Florida, Georgia, and North Carolina. This relatively small native range suggests it’s adapted to the specific climate and water conditions of the southeastern coastal plain and piedmont regions.

Why Consider Prickly Hornwort for Your Water Garden?

As a native aquatic plant, prickly hornwort offers several potential benefits:

  • Supports local ecosystems by providing habitat for native aquatic wildlife
  • Helps maintain water quality through natural filtration
  • Adds interesting underwater texture and movement to ponds and water features
  • Requires no soil since it’s a free-floating or loosely anchored plant
  • Being perennial, it can provide year-round structure in suitable climates

The Challenge of Growing Prickly Hornwort

Here’s where things get a bit tricky: specific growing information for Ceratophyllum muricatum australe is quite limited. This particular subspecies appears to be less commonly cultivated than other hornwort varieties, which means finding detailed care instructions or even sourcing the plant itself can be challenging.

What we do know is that, like other hornworts, it’s likely an entirely aquatic plant that prefers still or slow-moving waters. It probably thrives in the warm, humid conditions typical of its native southeastern range.

Should You Plant It?

If you live within or near the plant’s native range of Florida, Georgia, or North Carolina and have a pond or water garden, prickly hornwort could be an excellent native choice. However, the limited availability and specific growing information make it more suitable for experienced aquatic gardeners or those particularly committed to using local native species.

For beginners or those outside its native range, you might want to consider other well-documented native aquatic plants that are easier to source and grow successfully.

Finding and Growing Prickly Hornwort

If you’re determined to try growing this native beauty, here are some tips:

  • Contact native plant societies in Florida, Georgia, or North Carolina for sourcing advice
  • Check with specialized aquatic plant nurseries that focus on native species
  • Ensure your water garden conditions match its native habitat preferences
  • Consider starting with other native hornwort species to gain experience with the genus

The Bottom Line

Prickly hornwort represents the fascinating world of specialized native aquatic plants. While it may not be the easiest plant to grow or find, it offers aquatic gardeners in the Southeast a chance to support local ecosystems with a truly regional native species. Just be prepared for a bit of detective work in tracking down both the plant and specific care information!

If you’re passionate about native plants and have experience with aquatic gardening, prickly hornwort might be worth the extra effort. For everyone else, there are plenty of other beautiful native aquatic options that are better documented and more readily available.

Prickly Hornwort

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Magnoliidae

Order

Nymphaeales

Family

Ceratophyllaceae Gray - Hornwort family

Genus

Ceratophyllum L. - hornwort

Species

Ceratophyllum muricatum Cham. - prickly hornwort

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA