Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
62. Cyperaceae, the Sedge Family
11. Scirpus L. -- Bulrush
8. Scirpus pallidus (Britt.) Fern. -- Pale bulrush
Loosely tufted perennial with short rhizomes, 5-17 dm tall, the culms trigonous.
Leaves sheathing most of the culm; blades ascending, usually not
surpassing the inflorescence, 5-17 mm wide; sheaths entirely green; involucral
bracts 3-4, foliaceous, slightly to much exceeding the inflorescence, the
longest to 15 cm long. Inflorescence a terminal, rather compact, umbelliform
cyme containing many dense glomerules of numerous spikelets, the glomerules
densely clustered at the ends of pedicels to 12 cm long; spikelets very
numerous and crowded, 2-5 mm long, 1-2.5 mm thick; scales hyaline except
for the broad, green midvein, blackish on the sides, mostly 2-2.5 mm long including
an awn 0.4 mm or more long; perianth mostly of 6 white to tan bristles
shorter than or equaling the achene; stamens 3; styles trifid.
Achenes light green to pale tan, unequally trigonous, the ventral side
broadest, the achene body 0.7-1 mm long, 0.5-0.7 mm wide, with a beak to 0.2
mm long. Jul--Aug. Wet meadows, shores, ditches, stream banks, springs and other
wet places; common e and c, less so w; (Ont. to Alta. and WA, s to MO, TX, NM
and AZ). S. atrovirens Willd. var. pallidus Britt.
Rarely entering the region in the extreme ne part (e.g., Pembina Co., ND)
is the very similar S. atrovirens, of which S. pallidus is often
treated as a variety. S. atrovirens differs from S. pallidus
chiefly as follows: Scales dark green on the sides, eventually turning
brownish or blackish, 1-2 mm long including a mucro 0.1-0.2 mm long.
Previous Section -- Scirpus nevadensis S. Wats.
-- Nevada bulrush
Return to Family -- Cyperaceae - The
Next Section -- Scirpus pendulinus Muhl.