Regularity: Regularly occurring
Global Range: Stylisma pickeringii var. pickeringii has been reported from nineteen counties in New Jersey, North Carolina, South Carolina, Georgia, and Alabama, although in recent searches, it has not been relocated in four of these counties (Kelly and Weakley 1992). A report from Mississippi is now believed to have been misidentified as S. pickeringii var. pattersonii, which is extant in that state (Kelly and Weakley 1992). HISTORIC RANGE: A state-by-state breakdown of historic and/or extirpated county records for S. pickeringii var. pickeringii follows (Myint 1966, Kelly and Weakley 1992): New Jersey - Atlantic (1882), Burlington (1860, 1885, 1910, 1930, 1946) and Ocean (1887) Counties; in a 1991 survey, no plants were found at seven historic or recent sites (Kelly and Weakley 1992); North Carolina - New Hanover (1958) and Richmond (1958) Counties; South Carolina - Lexington (1985) County; Georgia - Dougherty (1947) and Tattnall (1976) Counties; Alabama - Autauga (n.d.) County. CURRENT RANGE: The following is a state-by-state breakdown of the extant occurrences currently known (number in parentheses represents number of occurrences in that county) (Kelly and Weakley 1992, SCHT 1992, North Carolina Natural Heritage Program 1993): New Jersey - Atlantic (not seen since 1982), Burlington (8), and Ocean (3) Counties; North Carolina - Cumberland (3 totaling 4 sites), Harnett (1), Hoke (11 totaling 49 sites), Moore (2), New Hanover (1, the type locality rediscovered in 1993), Richmond (7 + 2 shared with Scotland County totaling 11 sites), and Scotland (3 + 2 shared with Richmond County totaling 6 sites) Counties; a total of 30 occurrences with 72 sites (North Carolina Natural Heritage Program 1993); South Carolina - Aiken (1), Horry (2), Lexington (3), and Marlboro (1) Counties; five in xeric sandhills sites and two along the Little Pee Dee River in the Outer Coastal Plain (SCHT 1992); Georgia - Richmond (5) and Taylor (1) Counties; Alabama - Autauga (1) County.
Stylisma pickeringii var. pickeringii can be confused with S. pickeringii var. pattersonii and with S. patens ssp. angustifolia. Myint (1966) described characters that can be used to distinguish the taxa. While S. pickeringii var. pickeringii has style branches that are mostly 2-3 mm long and subequal, S. pickeringii var. pattersonii has style branches that are mostly 1-1.5 mm long and unequal. S. pickeringii var. pickeringii also has mostly obtuse sepals, whereas pattersonii has mostly acute sepals. S. patens ssp. angustifolia has styles free to near the bases of the stigmas, bracteoles of flowers less than 1 cm long, and stylopodia 1-2 mm long. In contrast, S. pickeringii var. pickeringii has styles fused nearly to bases of the stigmas, bracteoles longer than 1 cm, and stylopodia to 3-4 mm long.
Comments: Stylisma pickeringii var. pickeringii inhabits dry to xeric, nutrient-poor, well-drained, coarse sandy soils with little competing vegetation or litter (Kelly and Weakley 1992). Tree cover is sparse to non-existent, composed of pines and scrubby oaks, although a few occurrences on Fort Bragg are in moderately dense pine/oak woodland areas. Most plants have been found on aeolian sand deposits, including Lakeland sands in North Carolina, Lakewood/Lakehurst sands in New Jersey, as well as sandy river terraces along the Little Pee Dee River in South Carolina and the Little River in North Carolina (Kelly and Weakley 1992).
Stylisma pickeringii occurs on the Coastal Plain in the New Jersey Pine Barrens ecoregion, in areas that experience frequent burning or mechanical disturbance. Dominant woody vegetation is Pinus rigida (pitch pine) and Quercus ilicifolia (scrub or bear oak), but much bare sand occurs between boles. From North Carolina to Alabama, it occurs primarily in the Sandhills region, with a few occurrences on stable sand ridges of the Outer Coastal Plain. Both regions historically experienced naturally high fire frequencies.
In South Carolina, most occurrences are on sandy roadsides in Lakeland (Typic Quartzipsamments) and Vaucluse (Typic Hapludults) soils, growing with similar associates as sites in North Carolina (SCHT 1992). One site supports a very large occurrence of Chrysoma pauciflosculosa; at least two support Ceratiola ericoides. On Fort Bragg and the nearby Sandhills Game Land, Stylisma pickeringii is more often found where the natural community has largely been removed, e.g., xeric, essentially bare sandy roadsides, large, sparsely vegetated (grasses, lichens, herbs, scattered low shrubs) parachute drop zones, tank training sites, and other similar areas cleared for military training exercises. In these cases mechanical disturbance is thought to provide habitat by reducing competition and possibly scarifying seeds or in some way facilitating germination. These drop zones occupy the highest ridges and knolls on Fort Bragg. It is assumed that Stylisma was here originally and has recolonized significant portions of these clearings. At all sites, plants grow most vigorously in semi-stable sand, apparently an important feature of the species' autecology. Associates in these clearings include a mix of natural and weedy (although mostly native) species, such as Quercus laevis, Q. marilandica, Pinus palustris, Diospyros virginiana, Rhus copallinum, Rubus sp., Gaylussacia dumosa, Aristida stricta, Aristida tuberculosa, Eragrostis spp., Phytolacca americana, Lespedeza spp., and Aureolaria pectinata. Soils usually are of the Candor (Arenic Paleudults) or Lakeland (Typic Quartzipsamments) series (Hudson 1984, NCNHP 1993). The natural plant community which occurs in undisturbed xeric areas in the North Carolina Sandhills is classified as Xeric Sandhill Scrub (Schafale and Weakley 1990). This community is dominated by a usually sparse canopy of Pinus palustris (longleaf pine) over a moderately dense to dense Quercus laevis (turkey oak) understory. Ground layer species that occur with the sparse to moderately sparse Aristida stricta (wiregrass) layer include lichens, Gaylussacia dumosa var. dumosa, Pityopsis aspera var. adenolepis, Lupinus diffusus, Epigaea repens, Schizachyrium scoparium, Agalinis setacea, Aureolaria pectinata, Cirsium repandum, Minuartia caroliniana, and Selaginella arenicola (Weakley 1991, TNC 1991-93). Stylisma has also been found in association with other rare Sandhills species, including Astragalus michauxii, Orbexilum lupinellum, Phaseolus sinuatus, Polygala grandiflora, and Pyxidanthera barbulata var. brevifolia (TNC 1991-93). Stylisma pickeringii also occurs in slightly different but still xeric habitat along exposed dry bluffs and on xeric terraces of the Little River in North Carolina and the Little Pee Dee River in South Carolina. Most of these terrace occurrences are found where a disturbance (such as sand and gravel extraction) has created a more-or-less open canopy over a semi-stable substrate. These sites are characterized by a sparse pine canopy (Pinus palustris and/or P. taeda), few or no shrubs, and a sparse covering of wiregrass and other herbs. Other rare taxa that occur at these sites include Amorpha georgiana var. georgiana, Nestronia umbellula, and Warea cuneifolia (TNC 1991-93). Soils at North Carolina riverside sites are variable and include the following series: Blaney (Arenic Hapludults), Chewacla (Fluvaquentic Dystrochrepts), Kalmia (Typic Hapludults), Lakeland (Typic Quartzipsamments), Pactolus (Aquic Quartzipsamments), and Tarboro (Typic Udipsamments) (Hudson 1984, NCNHP 1993); most show signs of excavation or other disturbance.
One current population along the Little Pee Dee River in South Carolina, which occurs as "numerous clumps scattered on a dry fluvial sandridge island ... in near pristine condition" (SCHT 1992), and another on an undisturbed terrace on private property along the Little River in North Carolina just north of Fort Bragg (NCNHP 1993), may represent two of the few truly natural sites for the species.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 21 - 80
Comments: Forty-three extant occurrences are known, following status survey fieldwork in New Jersey, North Carolina, South Carolina, Georgia, Alabama, and Mississippi (1991).
National NatureServe Conservation Status
Rounded National Status Rank: N3 - Vulnerable
NatureServe Conservation Status
Rounded Global Status Rank: T3 - Vulnerable
Reasons: There are 43 known extant occurrences, many of which are vulnerable to habitat destruction.
Global Short Term Trend: Decline of 10-30%
Comments: Each state has at least one historical and unrelocated occurrence, and every state is experiencing habitat destruction.
Comments: The factors affecting the continued existence of the species as identified in the Status Survey (Kelly and Weakley 1992) are as follows: (1) The present or threatened destruction, modification, or curtailment of its habitat or range, mostly through commercial and residential development, paved road and foodplot construction, trampling by off-road and military vehicles, trash dumping, and fire suppression. (2) The inadequacy of existing regulatory mechanisms.
Only North Carolina and Georgia have laws protecting Stylisma from taking. Only North Carolina provides for management and only New Jersey protects its habitat. After habitat destruction, disruption of the natural fire regime is probably the greatest threat to Stylisma pickeringii occurring in intact, upland habitats. Historically, frequent fires probably maintained large areas suitable for Stylisma pickeringii var. pickeringii; removal of this disturbance from the landscape over the past century, as well as altering its timing, frequency, and intensity have probably reduced large numbers of plants.
Occurrences along the Pee Dee River and Little River terraces may also be threatened by natural or human-related alterations in the flood cycles of these waterways. Although roadside and parachute drop zone populations appear to be thriving in the presence of some level of ground disturbance, they are always under the constant threat of catastrophic disturbance. Roadbed widening or heavy equipment activity on the drop zones, for example, may dramatically reduce the number of individuals in an occurrence. These reductions, if they come at a crucial stage in the species' reproductive cycle (i.e., during flower or fruit production), could have severe long-term effects on the population. Although it appears that this species can rebound from large disturbances, it is not clear how much seed bank and genetic diversity is lost from each disturbance.
Biological Research Needs: A top priority research need is to determine Stylisma's habitat requirements, including the importance of fire (seasonal timing, intensity, and frequency) and disturbance (mechanical) on plant health and reproduction. There is also a need to determine under what conditions Stylisma pickeringii germinates, especially in natural and semi-natural plant communities and to answer specific questions regarding pollination ecology, genetic impoverishment, and genetic and ecological distinctiveness among populations throughout its range. Other studies should focus on what environmental factors other than fire exclusion may contribute to the limited distribution of the species (such as seed predation and fungal infection) (Prince 1992). Stylisma pickeringii's ability to colonize xeric disturbed areas such as the Fort Bragg drop zones and sandy roadsides makes it perhaps a valuable soil stabilization species. Researchers with the Soil Conservation Service may be interested in experimenting with this species, especially for the numerous erosion control projects on Fort Bragg. Propagators at the North Carolina Botanical Garden in Chapel Hill, North Carolina, are studying germination requirements for the species in both greenhouse and in situ test areas. No other research activities are known for the species.
Names and Taxonomy
Comments: As treated here (following Kartesz, 1994 checklist), includes Fernald's Brewaria pickeringii var. caesariensis.
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