OregonFlora: Sparganium angustifolium

	Sparganium angustifolium
	floating bur-reed, narrow-leaf bur-reed
Habit	Plants terrestrial to emergent, to 2.5 m.
Leaves	0.2–1 m × 2–5(8) mm, not keeled; uppermost leaf extending above inflorescence.
Inflorescences	emergent, unbranched, staminate heads 3–4(5), pistillate heads 1–4, 1–3 cm diameter in fruit.
Flowers	tepals lance-ovate; without spot near tip; tips toothed; stigma 1.
Fruits	red to brown; dull; body 3–4 × 1.5–2 mm; narrower at midpoint; beaks straight, 1.5–2 mm long.
2n	=30.

	Sparganium angustifolium
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Lakes, ponds, and streams, occasionally shorelines. Flowering Jul–Aug. 900–2800m. BR, BW, Casc, Sisk. CA, ID, NV, WA; east to Newfoundland, southeast to NM; circumboreal. Native. Sparganium angustifolium is known to hybridize with S. emersum in habitats where both species are present.
Source	Flora of Oregon, volume 1, page 507 Tamra Prior
Sibling taxa	S. emersum, S. eurycarpum, S. natans
Synonyms	Sparganium angustifolium var. multipedunculatum, Sparganium emersum var. multipedunculatum, Sparganium simplex var. multipedunculatum
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Sparganium angustifolium

floating bur-reed, narrow-leaf bur-reed

Habit

Plants terrestrial to emergent, to 2.5 m.

Leaves

0.2–1 m × 2–5(8) mm, not keeled; uppermost leaf extending above inflorescence.

Inflorescences

emergent, unbranched, staminate heads 3–4(5), pistillate heads 1–4, 1–3 cm diameter in fruit.

Flowers

tepals lance-ovate; without spot near tip;

tips toothed;

stigma 1.

Fruits

red to brown; dull;

body 3–4 × 1.5–2 mm; narrower at midpoint;

beaks straight, 1.5–2 mm long.

=30.

Sparganium angustifolium

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Lakes, ponds, and streams, occasionally shorelines. Flowering Jul–Aug. 900–2800m. BR, BW, Casc, Sisk. CA, ID, NV, WA; east to Newfoundland, southeast to NM; circumboreal. Native.

Sparganium angustifolium is known to hybridize with S. emersum in habitats where both species are present.

Source

Flora of Oregon, volume 1, page 507
Tamra Prior

Sibling taxa

S. emersum, S. eurycarpum, S. natans

Synonyms

Sparganium angustifolium var. multipedunculatum, Sparganium emersum var. multipedunculatum, Sparganium simplex var. multipedunculatum

Web links