BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Scirpus acutus | Hardstem Bulrush 



GENERAL BOTANICAL CHARACTERISTICS : 
Hardstem bulrush is a native, perennial graminoid.  Culms are slender
and erect, usually 3.3 to 10 feet (1-3 m) tall, but occasionally
reaching heights of 16.5 feet (5 m) [24,27,38,45,48].  Leaves are
reduced to basal sheaths with blades up to 3.2 inches (8 cm) long [51].
Hardstem bulrush is densely colonial from extensive, stout rhizomes
[29,38,45,48,51]. 


RAUNKIAER LIFE FORM : 
   Geophyte
   Helophyte


REGENERATION PROCESSES : 
Sexual reproduction:  Hardstem bulrush reproduces by seed [29,54,56].
Seed is dispersed by wind and water [29,55,56,65].  It establishes well
from seed stored in the seedbank [34,54,55].  Hardstem bulrush seed
establishes and germinates best on moist, bare soil [29,56], but will
germinate submerged in up to 1.6 inches (4 cm) of water in the
laboratory [65].

Vegetative reproduction:  Hardstem bulrush reproduces from rhizomes
[51,62].  Adventitious shoots may arise from rhizomes that have extended
into pools from the littoral zone [62].


SITE CHARACTERISTICS : 
Hardstem bulrush grows best on sites with saturated soil or standing
water for most of the year.  It occurs in marshes, swamps, seeps,
washes, floodplains, along lake and stream margins, and in wet meadows
[27,35,38,44,82].  It grows in fresh or brackish water [18,45,51,57].
Soils are usually poorly drained [18,76] or continually saturated
[4,9,15,56].  Hardstem bulrush can grow in areas where the water table
is up to 5 feet (1.5 m) above or 0.33 feet (0.1 m) below the soil
surface [29,36,56,76].  In Montana hardstem bulrush is an obligate
wetland species [4] and an indicator of relatively stable water
conditions (areas where free water remains in the rooting zone for at
least part of the growing season and can be periodically flooded up to
6.6 feet [2 m]) [56].  In Utah hardstem bulrush is subordinate to Olney
threesquare because of limitations in salinity tolerance, shallow water,
and competitiveness [5].  Hardstem bulrush is fairly drought tolerant;
it can persist through several years of dry conditions [29].  Hardstem
bulrush grows in silt loam, clay, sandy loam, gravel, marl, and peaty
soils [12,29,33,38,76].

Elevations for hardstem bulrush are as follows:

                                  feet              meters

Arizona                        2,500-9,000         750-2,700    [41]
California                    <5,000-8,500      <1,500-2,550    [51]
Colorado                       3,500-9,000       1,050-2,700    [32,90]
Montana                        2,180-6,650         665-2,028    [4,31]
Oregon                         4,125-4,224       1,250-1,280    [88]
Utah                           3,620-8,800       1,097-2,640    [82,90]
Wyoming                        6,500-7,000       1,950-2,100    [90]
Yellowstone National Park      5,990-6,633       1,815-2,010    [8]
Saskatchewan                   1,650-2,640         500-800      [77]


SUCCESSIONAL STATUS : 
Hardstem bulrush is a dominant emergent on moist and saturated sites in
the northern plains and prairie states [13,40,54,72].  In Montana
hardstem bulrush colonizes newly exposed mudflats and drawdown areas
[29].  In Saskatchewan hardstem bulrush is one of the earliest rooted
macrophytes to invade flooded areas [15].

After hardstem bulrush becomes established in the hardstem bulrush
riparian site type in Montana, most other plant species are precluded
because of the saturated conditions and hardstem bulrush aggressiveness
[31].  Hardstem bulrush forms a stable dominance type on sites with
relatively constant water regimes; permanent standing water may result
in compositional shifts toward sedges (Carex spp.) [29].

In marl-bed vegetation of the Byron-Bergen Swamp of New York, hardstem
bulrush is dominant but may be replaced by shrubby cinquefoil
(Potentilla fruticosa) with accumulated litter [62].

Hardstem bulrush is found in the third sere of succession in Wisconsin
marshes, preceded by submerged and floating plant stages and followed by
sedge meadows, shrubs, and trees [20].


SEASONAL DEVELOPMENT : 
Hardstem bulrush flowering dates are as follows:

California          May-Aug          [51]
Colorado            June-Aug         [90]
Montana             June-Aug         [90]
Wyoming             June-Aug         [90]
Great Plains        June-mid Aug     [45]
Nebraska            June-Aug         [24]
North Dakota        July-Aug         [90]
North Carolina      July             [59]
Tennessee           July             [59]
Virginia            June-Sept        [87]

Related categories for Species: Scirpus acutus | Hardstem Bulrush