Triadenum fraseri (Spach) Gleason
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TAXONOMY
 
Family: Clusiaceae
Genus: Triadenum
 
Species Synonyms: Elodea fraseri Spach
Hypericum virginicum var. fraseri (Spach) Fern.
Triadenum virginicum var. fraseri (Spach) Cooperrider
Triadenum virginicum ssp. fraseri (Spach) J. Gillett
Common Names: marsh St. Johnswort
Fraser’s marsh St. Johnswort
 
DISTRIBUTION
 
Canada: east-central Saskatchewan – Manitoba – Southern Ontario – southern Labrador – Newfoundland – Nova Scotia
Saskatchewan: east-central Saskatchewan
Ecoregion: Mid-Boreal Lowland
 
HABITAT
 
Saskatchewan: in up to 2 feet of water in semi-aquatic environments, floating marshy sedge fens, open quaking bogs, or Phragmites islands
Associated Species: reed grass, yellow marsh marigold
 
RARITY STATUS
 
Provincial Status According
to Harms (2003):
Endangered
Nature Conservancy Status:
G4G5 S1
Saskatchewan Species at
Risk Status:
None
COSEWIC Status:
None
 
Marsh St. Johnswort is endangered in Saskatchewan because it is extremely rare and highly regionally restricted. This species is almost always locally sparse.
 
SPECIES DESCRIPTION
 
Height: 30 – 60 cm
Roots: fibrous roots thick, yellowish-orange to brownish; rhizome creeping
Leaves: opposite, stalkless to claspin, 3 – 6 cm long, 2 – 3 cm wide, round to oval or oblong, base rounded, apex rounded to obtuse, hairless, lower surface black-dotted and slightly bluish
Inflorescence: flowers axillary or terminal, stalked
Flowers: 1 – 2 cm wide; sepals 5, to 5 mm long, oval to lance-shaped, tip acute; petals 5, 5 – 10 mm long, overlapping in bud, exceeding sepals, pinkish to greenish to purplish; stamens 9, united into 3 bundles opposite, orange glands; styles 3, < 1.5 mm long, free
Fruits: capsule to 12 mm long, ovoid to oblong
 
TRIADENUM VERSUS HYPERICUM IN SASKATCHEWAN
 
1 Leaves oval to oblong; petals pink to purplish or greenish, overlapping in bud; stamens 9, bundled
Triadenum fraseri
1 Leaves narrowly lance-shaped; petals yellow, rolled in bud; stamens numerous, free or bundled
Hypericum majus