The specific epithet davisii is named after Emerson Davis who was alive from 1798-1866 and was an "amateur student of Carex" (Fernald 1970).
There are currently twelve known populations and at least a dozen historical sites. At one time, it was thought this sedge was mostly restricted to woodland edges near the freshwater high tide mark along the Hudson River. Recently, additional populations have been found at various inland sites. As more people become familar with this plant, we should expect to find more populations. The additions of these new populations may represent a positive trend for a species that is expanding its range, or it may simply be another sedge that has been grossly overlooked.
Most extant populations have only been monitored once so trends are hard to determine for these populations. One population appears to have increased over a 21 year period although the apparent increase may be the result of an incomplete initial survey. Two other populations appear to have remained stable over a period of 8 to 13 years. One of these populations is in a high use park and was recently moved to avoid extirpation. The success of the relocation is not known. Overall short term trends are not clear but may indicate a stable situation.
One known historical site is believed extirpated. There are an additional 12 sites that have not been seen in over 20 years but it is unknown if these populations are still extant. All extant sites have fairly small populations but it is unknown if this is because they have decreased in number over time or if they have always been small. Since some of the sites are near destroyed habitat it is likely that some of these populations may have been larger in the past. Overall the long term trends are not clear but appear to indicate at least a slight decline.
Threats include invasive species including Ailanthus altissima and Alliaria petiolata; recreational development (boat launch construction); and trampling.
Follow up work needs to be done for the one extant population that was relocated. Invasive species management may be needed at a few extant sites.
Surveys of historical populations and monitoring of extant populations is needed.
Carex davisii occurs in mesic limestone, rich bottomland, and floodplain forests. It also occurs in wet meadows and open gravel bars of large rivers. It is often found near rivers and there are many populations adjacent to the Hudson River. The soils vary from mesic to wet or often seasonally flooded and sometimes are alluvial. Plants can occur or sometimes be restricted to disturbed areas (New York Natural Heritage Program 2005). Floodplain forests; rich deciduous forests and forest margins, usually along streams or in ditches, wooded ravine slopes, meadows, fields and thickets; often associated with calcareous soils (Waterway 2002). Rich woods and stream banks (Rhoads and Block 2000). Woods (Gleason & Cronquist 1991). Rich calcareous woods, meadows, and shores (Fernald 1970).
Carex davisii is mainly known from areas adjacent or relatively near the Hudson River from a little north of Albany south to Queens. There are some historical records scattered throughout central and western New York. New York is near the northeastern edge of its range.
Carex davisii is known from Connecticut, western Massachusetts, and Vermont west to New York, Ontario, and Wisconsin south to Maryland, Tennessee, Arkansas, and Texas (Sorrie and Somers 1999, Waterway 2002).
Carex davisii is a densely clumped, perennial, grass like plant The leaves are strap like and 3-8 mm wide. The bases of the lower leaves are maroon. Arising from the lower leaves are stems which are 30-100 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 4.5-6 mm long (Waterway 2002).
Carex davisii is a densely cespitose perennial. Basal leaf sheaths are maroon at their bases. Basal leaf blades are 3-8 mm wide and pilose abaxially. Culms are 30-100 cm tall. 3-5 spikes which arise singly at the nodes are present on the distal part of the culms. The lateral ones are on elongated peduncles. At least the lowest spikes arch or dangle at maturity. The lateral spikes are completely pistillate. The terminal spike is gynecandrous. Pistillate scales have an elongated awn tip that is 2.5-3.0 mm long. Perigynia are 4.5-6 mm long and abruptly narrow to a short (<0.5 mm long) beak (Waterway 2002).
Like many other Carex species especially ones in section Hymenochlaenae identification is easiest with almost mature to mature perigynia that are not yet easily shedding.
Carex davisii 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. debilis, C. formosa, C. gracillima, C. prasina, C. sprengelii, C. sylvatica, and C. venusta. Many of these are superficially similar. Carex davisii differs from all of them (except C. prasina) in having pistillate scales with an elongated awn (2.5-3 mm long) vs. with out or only a short awn (much less than 2.5 mm long). Other differences include:
Carex gracillima (one of the most common members in much of NY) and C. aestivalis have beakless and shorter perigynia. In addition, C. gracillima has generally glabrous foliage.
Carex debilis and C. arctata (both fairly common in NY) as well as C. castanea mostly have staminate terminal spikes. In addition C. debilis and C. arctata have glabrous leaf blades.
Carex sylvatica and C. sprengelii have brown or non-maroon basal sheath bases as well as elongated beaks (2.0-3.0 mm and 1.7-4.0 mm long respectively.)
Carex formosa like Carex davisii has a preference for calcareous soils but is more of northern species close to the southern edge of its range in NY. It has smaller perigynia 3.5-5.0 mm long and lateral spikes with a few staminate flowers at their bases.
Carex prasina is fairly distinct compared to C. davisii. It has spikes that are closer together, glabrous blue green foliage, and perigynia with two main veins but otherwise veinless (compared to 9-12 veins for C. davisii).
Carex venusta is confined to Long Island, in NY, where C. davisii is not known to occur. Carex venusta has glabrous leaf blades and pistillate scales that are suffused with brown or chestnut (vs. hyaline with green mid vein for C. davisii) (Waterway 2002).
The plants start to fruit in early June and the perigynia stay on the plants until mid-July although towards the end of this season the perigynia shed easily. Therefore, surveys are most successful from early June to early July.
The time of year you would expect to find Davis' Sedge fruiting in New York.
Carex davisii Schwein. & Torr.
Carex davisii had been placed in section Gracillimae (Mackenzie 1931-35, Fernald 1970, Gleason and Cronquist 1991) but is now recognized in a more broadly circumscribed section, Hymenochlaenae. With more research it is apparent that C. davisii may be moved to a different section (Waterway 2002).
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.
Mackenzie, K.K. 1931-1935. Cariceae. North American Flora 18: 1-478.
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.
Reschke, Carol. 1990. Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi.
Rhoads, Ann F. and Timothy A. Block. 2000. The Plants of Pennsylvania, an Illustrated Manual. University of Pennsylvania Press, Philadelphia, PA.
Sorrie, B.A. and P. Somers. 1999. The vascular plants of Massachusetts: A county checklist. Massachusetts Division of Fisheries and Wildlife, Natural Heritage and Endangered Species Program, Westborough, MA.
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 davisii. Available from: https://guides.nynhp.org/davis-sedge/. Accessed January 20, 2020.