Vascular Plants of North Carolina
Account for Common Bladderwort - Utricularia macrorhiza   Le Conte ex Torrey
Members of Lentibulariaceae:
Members of Utricularia with account distribution info or public map:
Google Images
Section 6 » Order Scrophulariales » Family Lentibulariaceae
Show/Hide Synonym
AuthorLe Conte ex Torrey
DistributionVery widely scattered in the Coastal Plain, essentially along the coast and near Albemarle Sound. One collection record from Wake County (if correct), in the eastern Piedmont. However, the SERNEC database shows collection records for only Chowan, Currituck, Hyde, and New Hanover counties, and the NCNHP database lists records only for Dare and Hyde counties. RAB (1968) and USDA list records for Perquimans and Wake counties, but the whereabouts of the specimens are not at SERNEC.

This species, which is generally considered to be that part of the U. vulgaris range in North America, is extremely widespread. It ranges across Canada from coast to coast, then south to NC, SC, TX, and CA. It is apparently lacking records from a few Southeastern states.
AbundanceVery rare in the Coastal Plain, and extremely rare to the eastern edge of the Piedmont (if a correct identification). Even though there are technically more counties represented on the species map for this species than for the very similar U. geminiscapa, the latter has recent collection records, whereas most of those for U. macrorhiza are old and some are not seemingly found in regional herbaria. Perhaps owing to this greater uncertainty of its rarity, the NCNHP has it listed as Significantly Rare, but it is not on the State Protected list. In addition, the State Rank rightfully has a ? -- S1? instead of a straight S1.
HabitatAs this is a larger species than the similar U. geminiscapa, it requires deeper water for growing; thus, it occurs in pools and ponds, and not in seepages.
PhenologyThis species blooms from May into September. It fruits shortly after flowering.
IdentificationThis is a rather large species of bladderwort. It grows in shallow water, like many others, but it does not have leaves that are so thick as to form a tangled underwater mat like some. It has a fairly tall flowering scape, up to 8-10 inches tall, with 6-20 fairly large yellow flowers that contain brown stripes, about 3/4-1-inch across. This scape continues underwater for a few inches. Another feature of this species are the long pedicels (flower stalks off the scape); these can be up to 2/3-inch long, but they are recurved when the flowers are finished blooming. Check additional references to help identify this rather showy species, as -- despite it being showy -- there is a disturbing "near lack" of recent records.
Taxonomic CommentsThis species was long considered to be named as U. vulgaris. However, many or most recent references have split out the North American taxon of U. vulgaris as a valid species on its own -- U. macrorhiza. Some references simply combine both, but have the combined Asia and North America species now named as U. macrorhiza.

Other Common Name(s)Greater Bladderwort
State RankS1?
Global RankG5
State StatusSR-O
US Status
USACE-agcpOBL link
USACE-empOBL link
County Map - click on a county to view source of record.
Photo Gallery
B.A. SorriePhoto taken July 2020, Valentine NWR, Cherry County, NE. HydePhoto_natural
Select a source
Select an occurrence type