Dionaea muscipula

Dionaea is a monotypic genus, and is considered by some to be in its own plant family (Dionaeaceae), and by others as part of the plant family Droseraceae (FNA 2015, Weakley 2024).

The Venus Flytrap, a carnivorous species, is a narrow endemic of the coastal plain and sandhills of North and South Carolina in the southeastern United States. It has very strict habitat requirements which include frequent fire, an open understory and wet, low nutrient, acidic soils. There are 74 extant natural occurrences and approximately 880,300 total individuals. Threats include development, habitat conversion to agriculture or silviculture, fire suppression, and plant poaching. There are some large populations on protected areas managed for conservation, such as North Carolina State Parks and State Game Lands, South Carolina Heritage Trust Preserves, and private conservation lands, it also occurs on Fort Liberty and the Croatan National Forest.

Venus Flytrap (Dionaea muscipula) occurs in the eastern United States, it is endemic to a narrow region of the coastal plain and sandhills of North Carolina and South Carolina. The historic range of the species is from Pamlico County, North Carolina south to Charleston County, South Carolina (Hamon et al 2021). As of 2023, the species is found in 11 North Carolina counties (Bladen, Brunswick, Carteret, Columbus, Craven, Cumberland, Hoke, New Hanover, Onslow, Pender and Sampson) and in South Carolina only in Horry County (USFWS 2023). Range extent was estimated to be about 20700 square kilometers, using herbarium specimens and NatureServe Network occurrence data collected between 1993 and 2024 (NatureServe 2024, SEINet 2024). Historical occurrences were known from seven additional counties in North Carolina (Beaufort, Duplin, Jones, Lenoir, Moore, Pamlico, and Robeson). In South Carolina, historical occurrences were known from Charleston and Georgetown counties (NatureServe 2024, USFWS 2023, Wichmann 2021). This species has been nearly extirpated in the inner coastal plain of North Carolina, and persists in the Sandhills of North Carolina only at a few sites on Fort Liberty (Hamon et al. 2021). Roberts and Oosting (1958) concluded that its total range is probably determined by its being limited to soils having a high water table, an organic hardpan usually not more than 60 cm below the surface, and a soil pH range of 3.9-4.5. Venus flytraps have been transplanted to the Pine Barrens of southern New Jersey, Yancey County in the mountains of North Carolina, the Apalachicola National Forest region in the Florida panhandle, and Escambia County, Alabama (Clewell 1985, Evert 1957, Schotz pers. comm., Weakley and Southeastern Flora Team 2024). These transplants outside its natural range are considered inconsequential for the conservation of the species.

By applying a 1 km separation distance to herbarium specimens and NatureServe Network occurrence data documented between 1993 and 2024, it was estimated that there are about 215 (and between 81 and 300) occurrences rangewide (NatureServe 2024, SEINet 2024). Due to size, proximity and suitable nearby habitat of various occurrences, they are generalized and clustered further into fewer, more extensive occurrences. Based on this, there are considered to be 140 occurrences, including 74 extant, 20 extirpated, 14 historical, and 29 which have not been relocated during the most recent surveys, despite searches in the appropriate locations (Hamon et al. 2021, NUSFWS 2023).

The greatest threats to Venus Flytrap are the degradation and loss of habitat from lack of prescribed fire, conversion to agriculture and intensive pine silviculture, residential and commercial development and right-of-way maintenance. Other stressors that could have negative effects on the species include plant poaching and small population size, drainage and groundwater abstraction (leading to loss of wetland habitat), nonnative invasive species, herbivory, and climate change. The southeastern coastal plain has one of the highest lightning frequencies in North America (Finch et al. 2012). The longleaf pine ecosystem is adapted to frequent fires. Venus Flytrap plants require open, sunny conditions to survive. This species is intolerant of dense shade. Frost (1998) called Venus Flytrap one of the most fire dependent species, noting that it begins to die out when fire-return intervals become longer than three years. Lack of fire is considered one of the main threats to Venus flytrap as it disrupts natural fire cycles which often results in increased shading and competition from woody plants, eventually causing the decline of herbaceous plant species. The longleaf pine ecosystem where Venus Flytrap plants are found has a historical average fire return interval of one to four years (Frost 1998, Guyette et al. 2012). Other types of habitat loss include the conversion of land from longleaf pine savannas and associated Venus flytrap habitat to agricultural lands, silviculture (tree farming), or residential and commercial development and are often permanent. Clearing land for conversion to agriculture and silviculture is destructive to Venus flytrap populations and often has permanent impacts on the landscape. The habitat is further altered to make it suitable for planting additional trees or agricultural crops. Residential and commercial development can have direct and indirect negative impacts on Venus flytrap populations and is often irreversible. Development also leads to fragmentation of natural areas which can negatively affect native species, even if not impacted directly. The human population within the range of Venus flytrap (southeastern North Carolina and northeastern South Carolina) is growing rapidly. Some of the most robust Venus Flytrap populations occur in Brunswick, Carteret, New Hanover, Onslow, and Pender counties in North Carolina and Horry County, South Carolina. According to the NC office of State Budget and Management, all of these NC counties had recent positive population changes ranging from 1.7% to 28% (NCOSBM 2022). Brunswick County, where two of the largest Venus Flytrap populations occur, had the second largest human population increase (28%) during the previous decade. Home to the largest Venus Flytrap population in South Carolina, the Horry County population increased 36.9% during that 10-year period (SCRFA 2019). Some Venus flytrap populations occur on roadsides and utility line rights of way (ROW) where roads and utility lines intersect suitable habitat for this species. These populations are vulnerable to road maintenance, road widening projects, herbicide application and mowing. Road maintenance and widening projects can destroy habitat where plants occur. Herbicides, which suppress plant growth, are often used to manage vegetation along road shoulders and in utility line ROW. Dormant season (winter) mowing is generally not problematic for disturbance-dependent species, as it helps reduce competition and maintain sites in an open condition. However, it is important that dormant season mowing be conducted when soils are not wet to avoid creating ruts which can kill small plants and disrupt the microtopography. Mowing that occurs during the growing season before plants produce mature seeds is harmful to the population because it eliminates seed production/reproductive potential for that year. In general, populations that occur in roadside and utility line ROW are extremely vulnerable to poor management actions. For many years, Venus flytrap plants have been the subject of illegal collection from the wild. Initially this was done so the plants could be sold at roadside markets and more wide scale in the horticulture trade. In more recent years, poaching may have also involved the pharmaceutical industry (McManus 2014). In 2014, the NC State Legislature passed a law making it a felony to take Venus Flytrap plants from someone else’s land without written permission of the landowner. In 10 years since the felony law was passed, four poaching events were caught by law enforcement officers. While the actual number of reported incidents is relatively small, large plant poaching events are not insignificant. Since 2014, overall poaching may have declined and has become a lesser threat than the lack of fire management, residential development and the other land use changes mentioned above (Margulies et al. 2024, USFWS 2023).