Sporobolus torreyanus (Schult.) Nash:
United States (North America)

Muhlenbergia torreyana (Schult.) Hitchc.:
United States (North America)

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Extant in southern New Jersey (through the pine barrens), eastern Maryland, southeastern North Carolina, and central Tennessee. Historical records for New York, Delaware, and Georgia. North Carolina harbors the next largest number of occurrences after New Jersey; Sorrie et al. (1997) report that there are several other plants known to exhibit a "bicentric type of distribution, with centers of distribution in the New Jersey Pine Barrens region and in the coastal plain of the Carolinas." Similarly, Sorrie and Weakley (2001) note that central Tennessee disjunctions of typically coastal plain plants are not uncommon.

Perennials, Terrestrial, not aquatic, Rhizomes present, Rhizome elongate, creeping, stems distant, Stems trailing, spreading or prostrate, Stems nodes swollen or brittle, Stems erect or ascending, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath and blad e differentiated, Leaf blades linear, Leaf blades very narrow or filiform, less than 2 mm wide, Leaf blades 2-10 mm wide, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence branches more than 10 to numerous, Flowers bisexual, Spikelets pedicellate, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Spikelets disarticulating beneath or between the florets, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes shorter than adjacent lemm a, Glumes 1 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma 3 nerved, Lemma glabrous, Lemma apex acute or acuminate, Lemma awnless, Lemma margins thin, lying flat, Lemma straight, Callus or base of lemma evidently hairy, Callus hairs shorter than lemma, Palea present, well developed, Palea membranous, hyaline, Palea about equal to lemma, Palea 2 nerved or 2 keeled, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Muhlenbergia torreyana possesses distinctive, scaly rhizomes (Sorrie et al. 1997). M. expansa may occur in close proximity, but can easily be distinguished from M. torreyana by its earlier phenology, much broader inflorescence, and cespitose, tussock-forming habit (Sorrie et al. 1997). Morphologically, M. torreyana resembles the western M. asperifolia but differs in its strigose, strongly compressed, keeled culms and less strongly divergent panicle branches (Flora of North America Editorial Committee 2003). According to Weakley (2008), in the vegetative condition, M. torreyana can be recognized by its forming clonal patches with evenly spaced, upright, blue-green tufts, each tuft a flattened stem with 5-10 ascending-erect, rather stiff, usually conduplicate leaves, the summit of each sheath with a pronounced cartilaginous thickening, easily felt by running the flattened stem from base to apex between thumb and forefinger.

Type fragment for Agrostis compressa Torr.
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Card file verified by examination of alleged type specimen
Preparation: Pressed specimen
Collector(s): -. Goldy
Year Collected: 1817
Locality: In swamps, pine barrens., New Jersey, United States, North America

Comments: Occurs in relatively open, perennially wet or moist (usually seasonally inundated) areas, usually on sandy or peaty substrates. Habitats include wet swales, open stream banks, open grass/sedge savannas in the pine barrens, cypress savannas, seasonally inundated pondshores, vernal or intermittently wet ponds dominated by grasses and sedges (often on edges), moist peaty meadows, and open bogs. Also occurs in wet, open disturbed habitats such as ditches, abandoned clay or sand pits, abandoned cranberry bogs, intermittently wet old fields, and road, powerline, and railroad ROW areas. Many sites are in lowland portions of the pine barrens (New Jersey), but sites are also known from oak barrens (oak barren bogs, moist grassy oak savannas) and Delmarva and Carolina Bays. In undisturbed areas, the open habitats required by this species are maintained by regular flooding and/or periodic fire (occurs in dynamic landscape mosaic, at least in some parts of the range). This grass often dominates over large areas, forming solid stands. In New Jersey, associated species include Dichanthelium wrightianum, Dichanthelium scabriusculum, Panicum agrostoides, Juncus caesariensis, Calamovilfa brevipilis, Lobelia canbyi, Ludwigia linearis, Platanthera integra, Xyris fimbriata, Asclepias rubra, Panicum virgatum, Carex barrattii, Cladium mariscoides, Scleria reticularis, Scirpus longii, Rhynchospora knieskernii, Rhynchospora pallida, Rhynchospora oligantha, and Rhynchospora cephalantha. In North Carolina, it is often under or near Taxodium ascendens and is associated with Lysimachia loomisii at one site. 0-150 m.

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

Estimated Number of Occurrences: 21 - 80

Comments: Approximately 67 occurrences are believed extant; the vast majority are in New Jersey, with several in North Carolina and a few in Tennessee and Maryland. Nearly 30 of these extant occurrences have not been visited in 20+ years, however, so would benefit from re-survey. An additional 19 occurrences are considering historical, 1 in Tennessee and the remainder in New Jersey.

United States

Rounded National Status Rank: N3 - Vulnerable

Rounded Global Status Rank: G3 - Vulnerable

Reasons: Muhlenbergia torreyana is extant through the New Jersey Pine Barrens, on the coastal plain in eastern Maryland and southeastern North Carolina, and disjunctly in central Tennessee. It is considered historical in Georgia and extirpated from New York and Delaware. Approximately 67 occurrences are believed extant; the vast majority are in New Jersey, with several in North Carolina and a few in Tennessee and Maryland. An additional 19 are considering historical, also mostly in New Jersey. In New Jersey, this species can be locally abundant where it occurs, dominating over relatively large areas; elsewhere in the range, it is considered more rare. Threats in New Jersey are considered relatively low, as most occurrences are in the pine barrens region where they are protected from direct habitat destruction. Nevertheless, impacts from recreational vehicles, siltation from nearby residential development, ditching, and fire suppression present some threat. Elsewhere in the range, threats include drainage, lowering of the water table, impacts from recreational vehicles, ditching, draining, logging, and fire suppression. Because this species is dependent on fire, water table fluctuations, and/or other disturbances to maintain open habitat, it is vulnerable to disruptions in these factors. Flowering typically occurs following fire.

Comments: Because this species depends on seasonal flooding to maintain open habitat at many sites, hydrological disruptions (e.g., ditching, draining, lowering of water table) would constitute a potential threat. Fire suppression is a threat throughout much of the range, particularly at sites more dependent on fire to keep the habitat open. In most of the areas that support this plant, recreational vehicles are a known or potential threat. Overall, threats in New Jersey are considered relatively low; most occurrences are in the pine barrens region, where they are protected from direct habitat loss by Pinelands region regulations. Additional threats in New Jersey include siltation from residential development, ditching, clearing for blue- and cranberry farming, and unfavorable roadside vegetation management practices. In Maryland, the occurrence is threatened by drainage and/or potential lowering of the water table. In North Carolina, in addition to vehicular disturbance, threats include pond pine encroachment due to past ditching and vegetation/soil disturbance from tree cutting and plowlines. In Tennessee, threats include logging, draining, and fire suppression.

Needs: Several additional occurrences should be protected. Substantial buffers around protected occurrences are often needed to maintain water table level. In MD, 30 acres including buffer for the Delmarva Bay would be adequate protection for the occurrence.

Comments: Distinct species. A different plant from the similarly named Muhlenbergia torrei.