OregonFlora: Scirpus pallidus vs. Scirpus pendulus

	Scirpus pallidus	Scirpus pendulus
	pale bulrush	drooping bulrush
Habit	Plants cespitose; rhizomes short.	Plants cespitose; rhizomes short.
Leaves	20–55 cm × 8–16 mm.	15–40 cm × 4–8(12) mm.
Inflorescences	terminal; branches ascending and drooping.	terminal; branches ascending and drooping.
Spikes	aggregated in a few dense clusters of 12–130; spikes sessile, narrowly ovoid, 4–5 × 1.8–2.3 mm; floral scales 1.6–2.8 mm; black or brownish black with pale midribs; apex with awn 0.4–0.6(1.2) mm.	in open cymes; central spike of each cyme sessile; others long-pedicellate; spikes ovoid to lance-ovoid or subcylindric, 5–10(12) × 2–3 mm; scales ovate, 2 mm, brown to red-brown with green midribs; apex mucronate; mucro 0.1–0.3 mm.
Flowers	perianth bristles persistent, 6; rather stout; straight or curved; longest bristles equaling achene, with retrorse teeth in distal 0.3–0.5, enclosed within floral scales; stigmas 3.	perianth bristles persistent or breaking off near base, 6; slender, strongly contorted; much longer than achene and often projecting far beyond it despite being strongly contorted; smooth, enclosed within floral scales or scarcely projecting beyond them; stigmas 3.
Achenes	plumply trigonous or plano-convex, 0.8–1.2 × 0.4–0.6 mm.	plumply trigonous or plano-convex, 1–1.2 × 0.6–0.8 mm.
2n	=56.	=40.

	Scirpus pallidus	Scirpus pendulus
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion	Marshes, streamsides, ditches. 0–700 m. BW. ID, WA; north to British Columbia, east to PA, southeast to TX. Native. Scirpus pallidus is similar to introduced S. georgianus, which has reduced perianth bristles.	Marshes, moist meadows, ditches. 50–1500 m. Casc, Sisk, WV. CA; east from MT to New Brunswick, south to Mexico; Australia. Native. Scirpus pendulus is recognized by its cylindrical spikes on drooping branches, with prominent green midribs on the brown floral scales.
Source	Flora of Oregon, volume 1, page 254 Barbara Wilson, Richard Brainerd, Nick Otting	Flora of Oregon, volume 1, page 255 Barbara Wilson, Richard Brainerd, Nick Otting
Sibling taxa	S. atrocinctus, S. congdonii, S. cyperinus, S. georgianus, S. microcarpus, S. pendulus	S. atrocinctus, S. congdonii, S. cyperinus, S. georgianus, S. microcarpus, S. pallidus
Synonyms		Scirpus lineatus
Web links	Local floras: BC, OR, WA Local Web sites: 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	Local floras: CA, OR 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

Scirpus pendulus

pale bulrush

drooping bulrush

Habit

Plants cespitose; rhizomes short.

Leaves

20–55 cm × 8–16 mm.

15–40 cm × 4–8(12) mm.

Inflorescences

terminal;

branches ascending and drooping.

terminal;

branches ascending and drooping.

Spikes

aggregated in a few dense clusters of 12–130;

spikes sessile, narrowly ovoid, 4–5 × 1.8–2.3 mm; floral scales 1.6–2.8 mm; black or brownish black with pale midribs;

apex with awn 0.4–0.6(1.2) mm.

in open cymes; central spike of each cyme sessile; others long-pedicellate;

spikes ovoid to lance-ovoid or subcylindric, 5–10(12) × 2–3 mm;

scales ovate, 2 mm, brown to red-brown with green midribs;

apex mucronate; mucro 0.1–0.3 mm.

Flowers

perianth bristles persistent, 6; rather stout; straight or curved; longest bristles equaling achene, with retrorse teeth in distal 0.3–0.5, enclosed within floral scales;

stigmas 3.

perianth bristles persistent or breaking off near base, 6; slender, strongly contorted; much longer than achene and often projecting far beyond it despite being strongly contorted; smooth, enclosed within floral scales or scarcely projecting beyond them;

stigmas 3.

Achenes

plumply trigonous or plano-convex, 0.8–1.2 × 0.4–0.6 mm.

plumply trigonous or plano-convex, 1–1.2 × 0.6–0.8 mm.

=56.

=40.