Montana Field Guide

PLANTS: Cespitose, perennial herbs with erect or arching stems reaching 10 to 80 cm tall. Plants have short shallow rhizomes and may also root at the stem tip by means of an apical bulbil. Source: Lesica et al. 2012.

LEAVES: Leaves are bladeless and reduced to 2 sheaths on the lower stem. The sheath of the distal leaf is firm and persistent. Leaf tip obtuse to subacute without a tooth-like projection. Source: Lesica et al. 2012.

INFLORESCENCE: A 4 to 15 mm long single spikelet with few to many flowers. Florets are tightly packed and spirally arranged. Source: Lesica et al. 2012.

The specific epithet rostellata originates from the Latin adjective rostellatus meaning “equipped with a beak” or “beaklike” (Arsenijevic et al. 1995). Eleocharis is made up of the two Greek words hele- and -charis meaning “marsh” and “grace” respectively (Merriam-Webster).

Beaked Spikerush flowers in July; mature fruits develop from July to August (Smith in Flora of North America (FNA) 2002).

Montana has eight Eleocharis species. They are generally mat-forming wetland herbs with inflorescences consisting of a single, solitary spikelet (Lesica et al. 2012).

Beaked Spikerush - Eleocharis rostellata, SOC
*Habit: A low-growing, tufted (cespitose) perennial. Stems are erect or arching and rooting at the tips.
*Stems: More or less flat, some arching to the ground and rooting at the tips. Plants are 10-80 cm tall.
*Spikelets: 4-10 mm long with few to many flowers.
*Achenes: Grayish-green, about 2 mm long. The upper portion of the achene is conical and confluent with the lower portion that is 3-sided to nearly round in cross section.
*Stigmas: 3

Creeping Spikerush - Eleocharis palustris,
*Habit: An erect, rhizomatous perennial.
*Stems: More or less cylindrical stems that are 7-90 cm tall with purple bases.
*Spikelets: 5-25 mm long with numerous flowers.
*Achenes: A yellow to brown, smooth, obovate achene that is 2-3 mm long. The upper portion of the achene is pyramidal in shape and appearing separated from the lower portion which is orbicular to lenticular in shape.
*Stigmas: 2

Few-flower Spikerush - Eleocharis quinqueflora,
*Habit: An erect, short-rhizomatous perennial.
*Stems: 5-25 cm tall and tufted.
*Spikelets: 4-8 mm long and usually with 5 flowers.
*Achenes: Brown, smooth, narrowly obovate, and 2-3 mm long. The upper portion of the achene forms a distinct beak that is confluent with the lower portion that is 3-sided.
*Stigmas: 3

Eleocharis rostellata prefers wet, often alkaline soils, associated with warm springs or fens in the valley and foothills zones of Montana (Lesica et al. 2012). It may also occur in various other types of alkaline wetlands including salt and brackish marshes, tidal flats, alkaline seeps, bogs, stream margins, hot spring edges, and swamps (Carey 1994).

ASSOCIATED SPECIES
In Montana wetlands, Beaked Spikerush is commonly associated with Common Arrowgrass (Triglochin miritimum), Hardstem Bulrush (Scirpus acutus), Torrey’s Rush (Juncus torreyi), and Alkali Muhly (Muhlenbergia asperifolia) (Carey 1994). Adjacent communities may be dominated by sedges (Carex spp.), Shrubby Cinquefoil (Dasiphora fruiticosa), or Tufted Hairgrass (Deschampsia cespitosa) (Greenlee 1999).

FIRE
Although wetland habitats have a lower probability of high intensity burning in any given year, they may experience varying levels of fire in seasons when the water table recedes (Carey 1994). After low intensity fires, Beaked Spikerush is able to sprout from its rhizomes even if all above ground plant matter is burned. It is also considered an early successional species and may recolonized wetlands after high intensity burns in marshy areas. A stable fire regime is important for keeping less fire tolerant species from displacing Beaked Spikerush.

BEAVER INTERACTIONS
Beaver are often necessary for maintaining suitable habitat for Beaked Spikerush by creating flood disturbance and saturated wetland conditions (Glisson 2003). Damming and flooding slows encroachment by woody species which creates open areas where shade intolerant species like Beaked Spikerush can receive at least partial sun. Due to their essential role in sustaining stable wetland habitat, beaver create suitable habitat for Beaked Spikerush, affecting its population dynamics and distribution.

HERBIVORY
Stems, roots, and achenes of spikerush (Eleocharis spp.) are an important food source for waterfowl (Carey 1994). Eleocharis rostellata dominated communities provide a source of forage early in the spring and attract various wildlife (Greenlee 1999). However, when plants have matured later in the season, palatability is low for livestock and other wildlife (Carey 1994).

SUCCESSIONAL STATUS
Beaked Spikerush is a pioneer species that can colonize marl beds and accelerate peat accumulation (Carey 1994). Eventually, hummocks of Beaked Spikerush form which may succeed into moss mats or larger hummocks dominated by shrubs. Later succession stages evolve toward cedar-dominated communities when water-table levels drop.

The above- and below-ground biomass of Beaked Spikerush was studied at various swamps in New York (Seischab et al. 1985). Above-ground standing biomass was highest in wet, minerotrophic sites followed by old, well-established sites, and least in young marl-bed sites. The marl bed site exhibited an early successional state, and therefore, plants allocated most of their resources to sexual reproduction and not vegetative growth. Below-ground biomass of plants in the old, well-established site was three times higher than in the wet, minerotrophic site and five times that of the young, marl bed site. This was most likely because the older site had been occupied by Beaked Spikerush for a longer than the other sites which created a greater accumulation of biomass. While allocation to specific structures fluctuated, overall biomass was not significantly different between sites, indicating that Beaked Spikerush is adapted to living in highly variable conditions and degrees of succession.

Beaked Spikerush has low seed abundance, slow seed spread rate, low seedling vigor, and moderate vegetative spread rate (USDA, NRCS 2019).

FLOWERS [Lesica et al. 2012]
Flowers consist of 6 perianth bristles, 3 stigmas, and 3 stamens. The perianth bristles are usually equal in length to the achene. The scales are 2-6 mm long, rounded, and brown to purple with broad, hyaline margins. The lowest scale is empty.

ACHENES [Lesica et al. 2012]
Achenes are grayish-green and about 2 mm long. The upper portion of the achene is conical and confluent with the lower portion that is 3-sided to nearly round in cross section.

VEGETATIVE [Carey 1994]
Beaked Spikerush has the ability to reproduce vegetatively by sprouting from short, shallow rhizomes. Vegetative regeneration may also occur through a process called layering in which the individual roots at the stem tip and sprouts from the apical bulbil.

LIFE CYCLE [Carey 1994]
Beaked Spikerush is a perennial species. Flowering occurs in late spring and is followed by seed production which begins in mid to late summer and continues into fall.

An essential first step to preserving existing populations of Beaked Spikerush is to monitor human activity to determine if habitat is being negatively impacted (Glisson 2003). Conservation measures to protect vulnerable habitat should address hydrologic alterations which could result from land development and certain grazing practices (Glisson 2003). Prescribed, low-severity fires may maintain early successional conditions in which Eleocharis species thrive (Glisson 2003).

Across its range many threats have been reported in the literature:

Major threats to Beaked Spikerush include habitat alteration and physical damage caused by livestock (Carey 1994). Populations that occur near hot springs and along stream margins are at higher risk of disturbance from recreation (Carey 1994). The narrow habitat at the edges of stream margins is vulnerable to damage by livestock trampling and soil compaction (Carey 1994). Soil compaction reduces moisture holding capacity which adversely affects Beaked Spikerush (Glisson 2003).

Noxious weeds and other invasive species also pose a serious threat to Beaked Spikerush populations (Glisson 2003). Aggressive non-natives such as Russian Olive (Elaeagnus angustifolia), Salt Cedar (Tamarix ramosissima), Canada Thistle (Cirsium arvense) and Purple Loosestrife (Lythrum salicaria) may out-compete Beaked Spikerush (Glisson 2003). Treating exotic plants with herbicides that then affect water quality is detrimental to Beaked Spikerush and other native wetland plants (Glisson 2003).

STATE THREAT SCORE REASON
Reported threats to Montana's populations of Beaked Spikerush are those that impact its habitat around hot springs (MTNHP Threat Assessment 2021). Noxious weeds and non-native grass species including Canada Thistle (Cirsium arvense), Ox-eye Daisy (Leucanthemum vulgare), and Redtop (Agrostis gigantea) are established in the vicinity of some populations. At least one population along a road is likely extirpated following a period of road construction and maintenance. Concerns that populations located on private land could be developed has been raised. The threat of altered hydrological conditions (i.e., shrinking wetlands) due to climate change is recognized as real at all locations; however short-term data or observations have not been brought forth. Information on the scope, severity, and/or timing of existing threats to Beaked Spikerush is needed.