The specific epithet venusta means beautiful or graceful (Stearn 2004). One of its common names is "graceful sedge." This sedge, like many plants that reach their north limit in New York, is restricted to Long Island.
Only known from a single site on Long Island. There are four other historical locations and two extirpated sites, all on Long Island. Long Island represents this species' northern range extent. There is very little suitable habitat remaining on Long Island, so the chances of finding new populations is low.
The one known extant population has been stable for at least 14 years. This is the only information known about how Carex venusta has been doing within the past 20 or so years and therefore short term trends are not clear but appears to be stable.
Two out of the seven populations ever known from New York are believed to be extirpated. There are an additional four populations which have not been seen since the early part of the 19 hundreds. It is unknown if these populations are still extant. The one extant population was first documented within the past 20 years. It might have been overlooked in the past as often happens with Carex species. Therefore, the long term trends indicate a decline.
Threats to the one extant population in NY include Phragmites encroachment. Potential threats include changes in the hydrology of the site.
Keep the Phragmites from negatively impacting the one known historic population.
More survey work is needed to determine the fate of the historical populations and perhaps find additional populations.
Carex venusta occurs in or near marshes and wet meadows. It also occurs in or near swamps and woody bogs as well as in wet thickets near salt marshes (New York Natural Heritage Program 2005). Swamps, peat bogs, mossy wetlands, and other wet habitats (Weakley 2004). Swamps forests, bogs, wet places in pine forests, bays, hammocks, roadside ditches (Waterway 2002). Swamps and wet woods near the coast (Gleason and Cronquist 1991). Sphagnous bogs, wet mossy woods and pinelands of the coastal plain (Fernald 1970).
In New York, Carex venusta is restricted to southern Long Island which is at the very northern and eastern edge of the species range.
Carex venusta sensu lato occurs from Long Island, New York south to Florida and west to Louisiana, Mississippi, and Tennessee (Waterway 2002).
Carex venusta is a densely clumped, perennial, grass like plant The leaves are strap like and 2.8-7.2 mm wide. The bases of the lower leaves are maroon. Arising from the lower leaves are stems which are 30-90 cm tall. Secondary branches come off of the upper portions of the main stems. Elongated flower/fruit clusters occur at the ends of these secondary branches. At maturity the secondary branches and the flower clusters nod or droop. The fruits are about 4.6-9 mm long (Waterway 2002).
Carex venusta is a densely cespitose perennial. Basal leaf sheaths are maroon at their bases. Upper leaf sheathes are pubescent at their apices. Basal leaf blades are 2.8-7.2 mm wide and glabrous. Culms are 30-90 cm tall. 4-6 spikes which arise singly at the nodes are present on the distal part of the culm. The lateral ones are on elongated peduncles which, with the spikes, arch or dangle at maturity. The lateral spikes are entirely pistillate. The terminal spike is staminate or sometimes gynecandrous. Pistillate scales are reddish brown to chesnut with hyaline margins and a green mid vein. Perigynia are 4.6-9 mm long (although NY specimens should be in the shorter end of this range), have a short stipe, and taper to a short (0.3-0.8 mm long) beak (Waterway 2002).
As with many other Carex species, especially ones in section Hymenochlaenae, identification is easiest when the plants are in immature to mature fruit but the fruits are not yet easily shedding.
Carex venusta is in section Hymenochlaenae affectionately known as the green dangly jobs which characterizes the dangling lateral spikes at maturity. There are numerous other species in this section that occur in New York including C. aestivalis, C. arctata, C. castanea, C. davisii, C. debilis, C. formosa, C. gracillima, C. prasina, C. sprengelii, and C. sylvatica. Many of these are superficially similar.
Carex aestivalis, C. castanea, C. formosa, C. prasina, and C. gracillima (one of the most common members in much of NY) have shorter perigynia (2.0-3.2, 2.5-5.0, 3.5-5.0, 2.5-4.0, and 2.0-3.7 mm long respectively). In addition, C. gracillima and C. aestivalis have beakless perigynia and C. castanea and C. formosa have pubescent leaf blades.
Carex sylvatica and C. sprengelii have brown or non-maroon basal sheath bases as well as elongated perigynia beaks (2.0-3.0 mm and 1.7-4.0 mm long respectively).
Carex arctata (which is fairly common in most of NY) and C. davisii have pistillate scales hyaline. In addition, C. arctata has glabrous leaf sheaths and C. davisii usually has pubescent leaf blades and elongated pistillate scale awns (2.5-3.0 mm long).
Carex debilis has lateral spikes narrower (2-3 mm wide vs. 4-5 mm wide for C. venusta) and internodes in the spikes larger (2-9 mm long vs. 1-3 mm long for C. venusta) (Waterway 2002).
The species is in fruit from early June till mid July but the fruits start to shed toward the end of this time period. Surveys are most successful in June.
The time of year you would expect to find Dark-green Sedge fruiting in New York.
Carex venusta Dewey
There appears to be two taxa lumped together under C. venusta but characters that have been used to separate the two vary more "within populations than between populations" (Waterway 2002). With more research clearer lines of separation may be elucidated. The two entities do show some differences in perigynia pubescence and length, chromosome numbers, and allozyme patterns. The more southern taxon occurs north to North Carolina and the more northern taxon occurs north to Long Island (Waterway 2002). Carex venusta is currently placed in section Hymenochlaenae but will probably be moved to another section once further studies are completed (Waterway 2002). It had previously been placed in section Sylvaticae (Fernald 1970, Gleason and Cronquist 1991).
Waterway, M.J. 2002. Carex Linnaeus sect. Hymenochlaenae (Drejer) L.H. Bailey. Pages 461-475 in Flora of North America Editorial Committee (editors), Flora of North America, North of Mexico, Volume 23, Magnoliophyta: Commelinidae (in part): Cyperaceae. Oxford University Press, New York, NY, USA. 608pp + xxiv.
Fernald, M.L. 1950. Gray's manual of botany. 8th edition. D. Van Nostrand, New York. 1632 pp.
Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.
Holmgren, Noel. 1998. The Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York.
Mitchell, Richard S. and Gordon C. Tucker. 1997. Revised Checklist of New York State Plants. Contributions to a Flora of New York State. Checklist IV. Bulletin No. 490. New York State Museum. Albany, NY. 400 pp.
New York Natural Heritage Program. 2010. Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY.
New York Natural Heritage Program. 2020. New York Natural Heritage Program Databases. Albany, NY.
Stearn, W. T. 2004. Botanical Latin. Fourth edition. Timber Press, Portland, Oregon. 546 pp +xiv.
Weakley, A.S. 2004. Flora of the Carolinas, Virginia, and Georgia. Working draft of March 17, 2004. University of North Carolina, Chapel Hill, NC. 871pp. Currently published by the author and available on the web at (http://www.herbarium.unc.edu/flora.htm).
Weldy, T. and D. Werier. 2010. New York flora atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research http://www.fccdr.usf.edu/. University of South Florida http://www.usf.edu/]. New York Flora Association http://newyork.plantatlas.usf.edu/, Albany, New York
Information for this guide was last updated on: February 13, 2006
Please cite this page as:
New York Natural Heritage Program. 2020. Online Conservation Guide for Carex venusta. Available from: https://guides.nynhp.org/dark-green-sedge/. Accessed March 31, 2020.