Sabatia Stellaris Pursh Sea Pink
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New England Plant Conservation Program Sabatia stellaris Pursh Sea pink Conservation and Research Plan for New England Prepared by Richard W. Enser Coordinator/Botanist, Rhode Island Natural Heritage Program Providence, Rhode Island For: New England Wild Flower Society 180 Hemenway Road Framingham, Massachusetts 01701 USA 508/877-7630 e-mail: [email protected] website: www.newfs.org Approved, Regional Advisory Council, May 2004 1 SUMMARY _____________________________________________________________ Sabatia stellaris Pursh, Sea Pink, is a member of the Gentian Family (Gentianaceae) that grows on open sandy soils at the upper edges of salt and brackish marshes and interdunal depressions. The plant is widely distributed in the states along the Atlantic and Gulf Coasts, and is considered to be abundant in the southern portion of its range. It is rare in New York and New England at the northeastern limits of its distribution. Sabatia stellaris is an annual that usually grows as one main stem with branching on the upper half. In the northern part of its range, plants grow to 20 cm. Flowers consist of a 4 to 7-lobed corolla that ranges from crimson-pink to light pink and sometimes white. The white-flowering form is widespread in the southern part of its range; however, this form constituted 75% of a Connecticut population in 2003, which is considered the first documentation of this form in New England. As an annual, S. stellaris exhibits extreme variability in the number of plants found at an occurrence in a given year. For example, in 2002 the estimated number of plants at three of the extant New England populations numbered about 1000, with an absence of plants from the fourth occurrence. In contrast, a resurgence in 2003 was marked by a combined total of more than 22,000 plants at all four sites. Currently, S. stellaris is known from seven extant sites in New England, four of which were observed in 2003 (two each in Connecticut and Rhode Island). The three remaining occurrences have not been reverified in at least four years, with the Massachusetts population not seen in 15 years despite repeated surveys. The principal threat to extant populations is the spread of invasive species, especially Phragmites australis; however, several populations have also disappeared despite no apparent alterations of the habitats. In these cases, it is suspected that population declines were precipitated by subtle changes in site conditions due to storms or other disturbances that resulted in increased salinity levels. The conservation objective for Sabatia stellaris in New England is to secure long-term protection and management of all extant populations. In order to achieve this objective, land acquisition may be considered at one site, but the primary course of action involves the control of Phragmites at three locations. In addition, the surprising annual variability in population vigor of known populations suggests that other occurrences may have to date been overlooked, and a search for these populations is considered a secondary conservation objective. i PREFACE This document is an excerpt of a New England Plant Conservation Program (NEPCoP) Conservation and Research Plan. Full plans with complete and sensitive information are made available to conservation organizations, government agencies, and individuals with responsibility for rare plant conservation. This excerpt contains general information on the species biology, ecology, and distribution of rare plant species in New England. The New England Plant Conservation Program (NEPCoP) of the New England Wild Flower Society is a voluntary association of private organizations and government agencies in each of the six states of New England, interested in working together to protect from extirpation, and promote the recovery of the endangered flora of the region. In 1996, NEPCoP published “Flora Conservanda: New England.” which listed the plants in need of conservation in the region. NEPCoP regional plant Conservation Plans recommend actions that should lead to the conservation of Flora Conservanda species. These recommendations derive from a voluntary collaboration of planning partners, and their implementation is contingent on the commitment of federal, state, local, and private conservation organizations. NEPCoP Conservation Plans do not necessarily represent the official position or approval of all state task forces or NEPCoP member organizations; they do, however, represent a consensus of NEPCoP’s Regional Advisory Council. NEPCoP Conservation Plans are subject to modification as dictated by new findings, changes in species status, and the accomplishment of conservation actions. Completion of the NEPCoP Conservation and Research Plans was made possible by generous funding from an anonymous source, and data were provided by state Natural Heritage Programs. NEPCoP gratefully acknowledges the permission and cooperation of many private and public landowners who granted access to their land for plant monitoring and data collection. This document should be cited as follows: Enser, R. 2004. Sabatia stellaris Pursh (Sea pink) Conservation and Research Plan for New England. New England Wild Flower Society, Framingham, Massachusetts, USA. © 2004 New England Wild Flower Society ii I. BACKGROUND _____________________________________________________________ INTRODUCTION Sabatia stellaris Pursh is an annual member of the Gentianaceae. Its distribution extends from southern New England along the Atlantic and Gulf coasts to Louisiana, including most of Florida, and disjunctly to several of the Bahama Islands, Cuba, and northern interior Mexico. Sabatia stellaris occurs primarily on open sandy soils at the upper edges of salt and brackish tidal marshes and interdunal depressions. In the southern part of the range, chiefly in Florida and Mexico, it is also found away from the coast in wet meadows and other open, generally sandy areas. Not considered to be a rare species on a global scale, at the northern limit of its distribution in New England it is known from less than ten occurrences. Currently, S. stellaris is present at two sites in Connecticut and four sites in Rhode Island, and is considered extant at one Massachusetts site where it has not been seen for 15 years. Based on this status, S. stellaris was listed in Division 2 of Flora Conservanda (Brumback and Mehrhoff et al. 1996), defining it as a regionally rare taxon with fewer than 20 occurrences in New England. In addition to the fact that it has never been widespread in New England, its presence in the region is diminishing. Although some populations are being impacted by the invasion of habitats by Phragmites australis and other invasive species, some occurrences have also disappeared despite any apparent alteration of the habitat. Consequently, a conservation plan is needed to define actions to maintain viable populations in New England. This plan summarizes the biology and ecology of S. stellaris, identifies knowledge gaps, and proposes conservation measures to insure the persistence of New England populations. The most important actions needed at this time include on-site management of invasive plants, and surveys for the species in new locations. DESCRIPTION Sabatia stellaris is an erect annual with fibrous roots, usually growing as one main stem with branches borne on the upper half of the stem. In New England, plants grow between 10 and 20 cm. tall, but in the southern part of its range heights may reach more than 50 cm (Wilbur 1955). The stem is smooth, with narrowly elliptic to spatulate leaves that are narrowed to an acute base and tip. The leaves are sessile and oppositely arranged. (Fernald 1950, Gleason and Cronquist 1991). Flowers consist of a 4 to 7-lobed corolla that ranges from crimson-pink to white, and calyx lobes that extend 3/4 the length of the corolla. Wilbur (1955) noted that S. stellaris is one of the most variable species of the genus. Plants in the northern part of the range tend to be more compact, less branched, 1 and have more broadly elliptical leaves. In contrast, specimens from Florida tend to be elongate, wiry, and slender with narrowly linear leaves (Perry 1971). Authors who have prepared the most comprehensive treatments of the genus Sabatia, Wilbur (1955) and Perry (1971), agree that the differences described above are not sufficiently consistent to warrant designation of a subspecies or variety within S. stellaris. There are four native species of Sabatia documented from New England, and all four are listed in Flora Conservanda (Brumback and Mehrhoff et al. 1996). Along with stellaris, Sabatia campanulata is listed in Division 2, S. kennedyana is included in Division 1 (Globally Rare Taxa), and S. dodecandra is a Division 4 (Historic) species. The occurrence of S. dodecandra in New England is based on three records from Old Lyme, Saybrook, and Guilford, Connecticut; although specimens are lacking for these records Fernald (1916) considered them to be valid. In addition, Sabatia angularis, a species of fields, prairies, and roadsides that reaches its easternmost distribution in Westchester and Queens Counties, New York, has been reported as a casual adventive in New England, at least as far east as Pembroke, Massachusetts (Fernald 1916). As well, the related western species, Sabatia campestris, has occasionally been found in fields and waste places, but apparently has not become established in New England (Fernald 1916). The following key helps to distinguish the species of Sabatia potentially occurring in New England, providing a compilation of characteristics from those keys described in Fernald (1950), Gleason and Cronquist (1991), Radford et al. (1968), and Godfrey and Wooten (1981). Key to the species of New England Sabatia 1. Flowers with 7-12 corolla lobes; plants perennial, often stoloniferous; flowers pink, rarely white. 2. Calyx lobes hyaline-margined, firm, linear, widest at base, with 1-3 obscure nerves or nerveless, 0.5-1.5 mm broad; corolla lobes 0.6-1.5 cm broad, the basal yellow spot of each lobe 2.5-5 mm broad; primary branches often opposite; terminal flower short-stalked.......................................S. kennedyana. 2.