Trichophorum planifolium (Spreng.) Palla:
United States (North America)

Scirpus verecundus Fernald:
United States (North America)

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Global Range: Trichophorum planifolium (=Scirpus verecundus) occurs from Massachusetts west to Ontario and south to Virginia and Kentucky, with disjunct occurrences in Missouri and southern Illinois.

Plants densely cespitose; rhizomes absent. Culms trigonous, 10–40 cm, scabrous proximal to inflorescence. Leaves: basal sheaths brown; distal leaf sheaths concave at mouth; blades 10–400 × 0.8–2 mm, equaling or exceeding culms at flowering and fruiting. Inflorescences: spikelets 3–8-flowered, 4.1–5.2 × 1.5–2.1 mm; bracts equaling spikelets, 3.7–6 mm, apex awned, awn to 3 mm. Spikelets: scales orange-brown to dark brown, midribs excurrent, apex mucronate. Flowers: perianth bristles 3–6, brown, terete, nearly equaling achenes, scabrous; anthers 1–1.5 mm. Achenes compressed trigonous, 1.5–2 × 0.7–1.1 mm.

Scirpus verecundus may be distinguished from S. hudsonianus by observing the number and character of the bristles. Scirpus verecundus has 3-6 short bristles (2 mm in length) which are round in cross-section and are not white. Scirpus hudsonianus differs by having 6 flat bristles which are white and much longer, reaching a length of 1-3 cm when they are mature. (Gleason 1963, Gleason and Cronquist 1991).

Scirpus clintonii has many morphological characteristics similar to S. verecundus, including the same bristle characteristics mentioned above, but differs by its scale characteristics. The midvein of the scales of S. verecundus are prolonged into a short, sharp, slender point, 0.5-1 mm long, while the midvein of scales in S. clintonii do not prolong into a point. The close relationship of these two species has been confirmed beyond morphological characteristics by comparing and observing similarities in the structure of achene epidermal cells. (Gleason 1963, Schuyler 1971, Gleason and Cronquist 1991).

This species may be confused in the field with other plants, such as Carex artitecta, C. emmonsii and C. pensylvanica which grow in similar habitat and appear vegetatively similar (Steyermark 1963, Crins 1986, Crins 1989, Tucker 1992).

The single spikelet of Scirpus verecundus makes the plant resemble Eleocharis species, but it differs in that a swollen style-base is absent, it has many flat leaves, and the achene characters are not the same (Gleason 1963, Braun 1967).

Isolepis planifolia Sprengel, Neue Entd. 3: 10. 1822; Baeothryon planifolium (Sprengel) Sojak; B. verecundum (Fernald) Á. Löve & D. Löve; Eleocharis planifolia (Sprengel) Nees; Scirpus planifolius Muhlenberg 1817, not Grimm 1767; S. verecundus Fernald

Comments: Scirpus verecundus occupies an array of habitats including dry fields, clearings, open woods and basic ledges (Fernald 1970, Gleason and Cronquist 1991). However, its primary habitat is that of dry, rocky woods, typically in association with hardwoods (principally oaks and beech).

The habitat as found in particular states is as follows:

Connecticut: Scirpus verecundus is known from dry, rich, rocky woodlands and slopes (often under American beech [Fagus grandifolia] and birch [Betula sp.]) and traprock ridges, sometimes on acidic soils (Tucker 1992, University of Minnesota Herbarium [MIN], CT NDD 1994).

Delaware: The primary habitat of the species in Delaware is second growth and mature oak-beech woodlands, typically on steep, dry, rocky slopes, usually with a northwest exposure. Associated plant species include Danthonia spicata, Epigaea repens, Fagus grandifolia, Hieracium venosum, Hypoxis hirsuta, Kalmia latifolia, Panicum dichotomum, Prunus serotina, Quercus alba, Q. rubra, Rhododendron nudiflora and Vaccinium vacillans. (McAvoy 1992).

Illinois: The species is known from dry woods and upland openings (Herkert 1991).

Kentucky: The two documented occurrences of this species in the state are associated with oak-hickory forests on sandstone slopes in the Cliff Section of the Cumberland Plateau(Medley 1993). One occurrence was located on a bench along a northeast-facing slope near a creek, while a second was above a river on a saddle along a ridge (DB NF 1989).

Maryland: Collection records of the species from Maryland suggest occupied habitat as moist forests, woods and meadows, and along streams (MD NHP 1994).

Massachusetts: A 1915 collection at the University of Minnesota (MIN) herbarium states habitat as being "woods" near Natick.

Missouri: Habitat of Scirpus verecundus in Missouri can be characterized as dry, rocky (over sandstone (Roubidoux), quartz-barite or chert), wooded slopes of ravines, often above streams. Associated plant species include Amianthium muscaetoxicum, Carex artitecta, Carex jamesii, Iris cristata and Trillium pusillum var. ozarkanum. Occurrences have been located at elevations ranging from 500-1,100 feet. (Steyermark 1963, MO NHD 1994).

Ohio: Occupied habitat is oak woods and south-facing exposures (Cusick and Silberhorn 1977).

Ontario: All of the populations in Ontario occur on relatively steep slopes under the cover of red oak (Quercus rubra) in association with Carex pensylvanica (Crins 1989). Eastern white pine (Pinus strobus) is often present in the overstory. It seems to prefer sites in which the canopy is not continuous, but in which small gaps occur and the forest floor is subject to considerable sun-fleck activity. Some type of disturbance (selective cutting, fire, trail edges) is usually evident near extant populations. In Ontario, it prefers neutral to slightly acidic, coarse-textured soils developed over highly calcareous parent materials. Cation (K, Mg, Ca) and phosphorous contents at occupied sites vary considerably (Crins 1989).

Overstory associated plant species found at Ontario occurrences include Acer rubrum, Acer saccharum, Amelanchier arborea, Carpinus caroliniana, Fraxinus americana, Fraxinus pennsylvanica, Ostrya virginiana, Pinus strobus, Prunus serotina and Quercus rubra. Shrub layer associates include Cornus racemosa, Cornus rugosa, Diervilla lonicera, Hamamelis virginiana, Prunus virginiana, Rubus strigosus, Symphoricarpos albus, Vaccinium pallidum, and Viburnum acerifolium. Some of the understory associates include Carex artitecta, Carex pensylvanica, and Collinsonia canadensis. (Crins 1986, Crins 1989, ONT CDC 1992).

Pennsylvania: The species has been documented from woods and dry, rocky slopes (Rhoades and Klein 1993).

Vermont: The primary habitat of extant and extirpated population is calcareous rocky outcrops and dry slopes (Popp 1992, VT NHP 1992). The single extant occurrence in the state is found in dry-moist oak-maple woods, often on or near ledges near the summit of a hill (@ 800 feet in elevation) (VT NHP 1992).

West Virginia: Two populations (one extant and one historical) have been documented from the state. The historical population was documented from rocky woods at 1300 feet. The extant population persists along a roadside bank at 2700 feet elevation. (WV NHP 1992).

Fruiting summer (Jun–Jul). Mesic to dry hardwood forests, usually with oak component, often on hillsides; 50–900 m; Ont.; Conn., Del., D.C., Ill., Md., Mass., Mo., N.J., N.Y., Ohio, Pa., R.I., Vt., Va., W.Va.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 21 - 80

Comments: There are approximately thirty-six documented occurrences: Deleware-six, Illinois-one, Kentucky-two, Missouri-sixteen+, Ontario-seven, Vermont-one, West Virginia-two. Sufficiently common to remain untracked in Massachusetts (occurs in eight counties), Connecticut, New York (post-1970 records from two counties, plus many historical locations), Pennsylvania, Ohio (16 counties), and Virginia (30 counties).

This species flowers before the leaves of the forest canopy develop and may be found in flower or fruit from late April to June (Steyermark 1963, Fernald 1970, Crins 1989, Gleason and Cronquist 1991).

Scirpus verecundus shows characteristics of a wind-pollinated plant by lacking a showy perianth and nectaries and having stamens and stigmas which are large and exserted. In the flowers, the anthers emerge beyond the scales before receptive stigmas develop (protandrous). Outcrossing of individuals is probably limited due to the low stature of the plants and the varied terrain in which populations may be found. (Crins 1989).

At flowering, the leaves are just beginning to lengthen, and they continue to elongate as the season progresses. The anthers become exserted in early to mid-May. Seed occurs from mid- May into June. The dispersal of seeds occurs from July to mid-August. The leaves and stems become matted by late July which may aid in seed dispersal and the formation of new colonial tufts. If new colonies are formed by this method, then nearby tufts are genetically similar. Even with the supposed genetic similarity, seeds form successfully at high rates. (Crins 1986, Crins 1989).

The establishment of new colonies of Scirpus verecundus may be limited by the amount of light reaching the forest floor through canopy gaps (Crins 1989).

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Species: 1
Species With Barcodes: 1

Canada

Rounded National Status Rank: N1 - Critically Imperiled

United States

Rounded National Status Rank: NNR - Unranked

Rounded Global Status Rank: G4 - Apparently Secure

Reasons: There are 36 documented occurrences from half of the states within the range of this species, and dozens of county records from states where it is relatively common. The species may be commonly overlooked.

Global Short Term Trend: Relatively stable to decline of 30%

Comments: Although habitat has likely been lost in recent years due to conversion, etc., the species appears to be relatively stable throughout its range. The status of the species may be more secure than currently reflected due to difficulty in identification and by being overlooked.

Comments: The primary limiting factor in the establishment of new colonies appears to be the amount of sunlight reaching the forest floor through canopy gaps (Crins 1989). Therefore, the loss of disturbance regimes (fire, etc.) in preferred habitat may threaten existing populations and diminish the establishment of new populations. In addition, competition from other plant associates (principally Carex pensylvanica) may inherently limit the establishment and spread of Trichophorum planifolium (=Scirpus verecundus) (Crins 1989). Habitat destruction or manipulation is a threat to existing populations and habitat; the placement of man-made structures on slopes to control erosion has had significant effects in Ontario. However, erosion of the susceptible soils in which this species grows could also be a threat if large portions of the forest cover are removed from slopes (Crins 1986).

Restoration Potential: Habitats with closed or closing canopies may be restored by creating gaps and openings which allow increased sunlight to the forest floor. At sites where competing plant species exist, the habitat may be restored by using removal methods to eliminate competing plants.

Preserve Selection and Design Considerations: Preserves should be designed so that adequate buffer area surrounds occurrences. Habitats are often found on steep slopes, and designs should account for disturbances which might create erosion and ultimate habitat degradation.

Management Requirements: Maintenance of canopy gaps within occupied habitats is a prerequisite for this species. In thin-soiled, rocky woodlands, canopy gaps may maintain themselves naturally. If habitat succession appears to be acting to close the canopy, actions to restore or maintain the open canopy may be warranted. This may occur through experimentation with a prescribed burning program, mechanical canopy thinning activity, or other action. If canopy thinning is exercised, care should be taken not to remove large portions of the forest canopy, as soils of habitats are often susceptible to erosion especially if they are on steep slopes as is often the case. It should be noted that very little information exists on proper management actions for this species. It may be best to precede with caution on an experimental, small-scale basis.

Crins (1989) stated that most observed populations in Canada were located in close proximity to disturbed areas (selective cutting, fire, trail edges). Maintenance of a disturbance regime of some sort may be a necessity for long-term viability of populations.

It is also important to ensure that habitat is not destroyed by threats such as development, trail creation and refuse dumping (McKay-Kuja 1992).

Management Programs: There are no management programs known to be in effect for this species.

Monitoring Programs: Baseline data was collected during one season for an Ontario population by students at the University of Toronto. Contact: Dr. R. L. Jefferies. Telephone: (416) 978-3534.

Management Research Programs: No current research for management purposes is known to be underway.

Management Research Needs: Research is needed into the incompatibility systems of this species as well as seed and seedling ecology and population ecology (Crins 1986).

Very little information exists on proper management actions for this species. Populations are often located in close proximity to disturbed areas (selective cutting, fire, trail edges). Research is need to determine the ecological requirements of this species as well as the methodologies required to maintain habitat to meet those requirements.

Biological Research Needs: Investigate incompatibility systems of the species as well as seed and seedling ecology and population ecology. Determine any variable response to different management practices (selective cutting vs. burning vs. natural disturbance regime).

Comments: Synonyms of Scirpus verecundus include Scirpus planifolius Muhl., and Trichophorum planifolium (Sprengel) Palla (Fernald 1948, Palmatier 1952, Steyermark 1963, Braun 1967, Rhoades and Klein 1993).

Common names for Scirpus verecundus include bashful bulrush, club-rush, and few-flowered club-rush (Crins 1989, DB NF 1989, Herkert 1991, Rhoades and Klein 1993).

Range distribution maps for this species may be found in the following sources: Steyermark(1963)(Missouri), Braun (1967), Crins (1986)(Ontario), Crins (1989), Argus and Pryer (1990), NYFA (1990)(New York), Herkert (1991)(Illinois), Harvill et al. (1992)(Virginia), Rhoades and Klein (1993)(Pennsylvania), Cusick (1994).

Illustrations of Scirpus verecundus may be found in the following sources: Gleason (1963), Steyermark (1963), Braun (1967), Fernald (1970), Schuyler (1971)(SEM photos of achene epidermal cells), Crins (1989).

The highly reduced nature of the inflorescence in Scirpus verecundus is potentially useful in studies of the phylogeny of the genus. This species could provide valuable information because evolutionary advancement is often represented by this kind of reduction. (Crins 1989).

This species can occur in rather large populations on relatively steep banks within forests which could be beneficial, along with other plant species, in stabilizing banks (Crins 1989).

Needs: Establish management and monitoring procedures for T. planifolium.

Stewardship Overview: Preserve designs should include adequate buffer area for management activities. Forested habitats should be managed so that gaps and openings are maintained to allow required sunlight to reach the forest floor. Plant species which compete with Scirpus verecundus should be eliminated from habitats. Occurrences should be protected from threats such as habitat development, erosion, trail creation, and refuse dumping. Monitoring of occurrences should be conducted on a frequent basis to assess population size and vigor, reproductive success, habitat quality, and threats. Research is needed to investigate the ecology of seeds, seedlings, and populations, as well as other aspects of its reproductive biology.