CPC Plant Profile: Canby's Dropwort
Search / Plant Profile / Oxypolis canbyi
Plant Profile

Canby's Dropwort (Oxypolis canbyi)

This shot of the Canby's dropwort, which stands 0.8 to 1.2 meters tall, highlights the flowers. Photo Credit: Marj Boyer
  • Global Rank: N/A
  • Legal Status: N/A
  • Family: Apiaceae
  • State: DE, GA, MD, NC, SC
  • Nature Serve ID: 139094
  • Date Inducted in National Collection: 02/10/1987

Canbys dropwort is a perennial aromatic herb with quill-like leaves, slender stems and reproduces by strong, fleshy rhizomes. It is found in the Coastal Plain regions of Delaware, Maryland, North Carolina, South Carolina and Georgia in pond cypress savannas, shallows of ponds, sloughs, and wet pine savannas. It is strongly clonal and most populations are maintained by asexual reproduction, although it does display compound clusters of small white flowers from August through September (Murdock and Raynor 1990). Canbys dropwort was officially listed as endangered on February 25, 1986 due to its rarity and vulnerability to habitat modification. The main cause of decline is habitat alteration.

Participating Institutions
CPC's Plant Sponsorship Program provides long term stewardship of rare plants in our National Collection. We are so grateful for all our donors who have made the Plant Sponsorship Program so successful. We are in the process of acknowledging all our wonderful plant sponsorship donors on our website. This is a work in progress and will be updated regularly.
Michael Kunz
  • 12/02/2021
  • Seed Collection

In September (2021) NCBG staff journeyed through the inner coastal plain of South Carolina to collect seeds of Oxypolis canbyi (Canby's dropwort).  With the help of the SC Natural Heritage Program, we found a healthy population in a wetland embedded in a recently burned long leaf pine savanna.  While collecting we noticed many of the seeds were empty, easily being crushed and falling apart as we collected.  We continued to collect, hoping for the best, but ultimately found only 7 filled seeds in the collection.  The habitat was extremely dry as the area experienced little rainfall in the month preceding collection.  It is possible the dry conditions affected seed maturation.  We will attempt again in 2022.

Center for Plant Conservation
  • 08/19/2021
  • Orthodox Seed Banking

In 2021, CPC contracted North Carolina Botanical Garden to recollect seed from a population currently held in long term orthodox seed storage as part of an IMLS-funded seed longevity experiment. The National Laboratory for Genetic Resources Preservation will evaluate how germination tested viability and RNA Integrity of seed lots decline over time in storage.

Nature Serve Biotics
  • 05/02/2017

Oxypolis canbyi is native to the Coastal Plain from southwestern Georgia through South Carolina to southeastern North Carolina, and from eastern MD to (historically) Delaware. Approximately 40 occurrences are believed extant, mostly in South Carolina and Georgia, with an additional 16 occurrences considered historical or of unknown status. There are likely over 10,000 total plants, as at least three Georgia occurrences have ""thousands"" of plants, and at least four South Carolina occurrences are described as ""very large."" Other sites have fewer plants. This species' herbaceous wetland habitats - characterized by long periods of inundation and little canopy cover - have declined significantly from historical levels due to drainage and conversion to pasture, farmland, and pine plantations. This threat continues to some extent presently. Habitat degradation is the other major threat to this species, primarily resulting from hydrological alterations and/or fire suppression, both of which can alter successional patterns to the detriment of this species. Water table-lowering activities in the general vicinity of sites can still constitute significant hydrological alteration, such that protecting the sites themselves may be insufficient to ensure persistence. A significant proportion of known occurrences are described as declining in habitat quality and/or population size; many require active management.

  • 01/01/2010

Alteration of wetland habitat (drainage and development) Collection Predation from black swallowtail butterfly caterpillars (USFWS 1986)

  • 01/01/2010

53 total populations, with 1 in Maryland, one in North Carolina, 28 in South Carolina, and 23 in Georgia. (USFWS 1986)

  • 01/01/2010

North Carolina Plant Conservation Program has permanent monitoring plots in the only North Carolina population

  • 01/01/2010

Habitat protection where known populations occur. Active management procedures are at present unclear.

  • 01/01/2010

Population demography/monitoring Competition and other community-level interactions Pollination biology Underground biotic/abiotic dynamics Response to fire

  • 01/01/2010

Collection from all populations Reintroduction


Be the first to post an update!

Taxon Oxypolis canbyi
Authority (Coult. & Rose) Fern.
Family Apiaceae
CPC Number 3064
ITIS 29545
Common Names Canby's cowbane | Canby's dropwort
Associated Scientific Names Oxypolis canbyi | Oxypolis filiformis var. canbyi
Distribution Coastal Plain, from Delaware to Georgia (USFWS 1986)
State Rank
State State Rank
Delaware SX
Georgia S2
Maryland S1
North Carolina S1
South Carolina S2

Found on the lowland plain of the mid-Atlantic coast in swamps, shallow pineland ponds, and wet pine savanna. (USFWS 1986)Some of the species associated with Canbys dropwort include Ilex myrtifolia, Nyssa biflora, Taxodium ascendens, Pinus serotina, Stillingia aquatica, Rhynchospora tracyi, R. inundata, Manisuris rugosa, Rhexia aristosa, Polygala cymosa, Pluchea rosea, Lobelia boykinii and Hypericum denticulataum (NatureServe 2001).

Ecological Relationships

Canbys dropwort has been found in many different coastal plain habitats, including pond cypress ponds, wet pine savannas, grass-sedge Carolina bays, shallow pineland ponds, and cypress-pine swamps. The largest and most vigorous populations are found on sites that are flooded for most of the year and have little if any canopy cover (Murdock and Raynor 1990). Soil types that support vigorous populations have medium to high organic content, high water table, are poorly drained and are acidic. Larvae of the black swallowtail butterfly (Papilio polyxenes) may be detrimental to the sexual reproduction of Canbys dropwort since these caterpillars regularly chew through the stem just below the inflorescence (NatureServe 2001). Therefore, most reproduction in Canbys dropwort is asexual.

Common Name Name in Text Association Type Source InteractionID
Lead Institution State Reintroduction Type Year of First Outplanting

Donate to CPC to Save this Species

CPC secures rare plants for future generations by coordinating on-the-ground conservation and training the next generation of plant conservation professionals. Donate today to help save rare plants from extinction.

Donate Today