ELEMENT STEWARDSHIP ABSTRACT FOR BIDENS BIDENTOIDES November 29, 1990 Stewardship Abstract No.: 001 By Alfred E. Schuyler For: State of New Jersey Department of Environmental Protection and Energy Division of Parks and Forestry Office of Natural Lands Management CN 404 Trenton, New Jersey 08625 Element Stewardship Abstract Element Stewardship Abstracts (ESA's) are prepared to provide land managers and other conservation workers with current biological and management related information on those species and natural ecosystems that are most important to protect or for which control is most needed. The abstracts organize and summarize data from numerous sources, including the literature and from researchers and managers actively working with the species or ecosystem. The ESA format was originally developed by The Nature Conservancy as a starting point for the stewardship of the many species and ecosystems, or elements, protected by the Conservancy. The New Jersey Office of Natural Lands Management is developing ESA's for those elements that are of particular importance as components of the biota of the state. This includes globally rare plant species that are also listed on New Jersey's official Endangered Plant Species List. The ESA serves several important functions. It helps to identify information gaps and target future research efforts. It provides a standard format for highlighting specific information about a species or community including its management needs. It also allows information to be readily communicated among various preserves, state offices, regional centers, natural heritage programs and private organizations. The ESA is a dynamic document that is continuously updated as new information becomes available. Users are encouraged to contribute their information to the abstract. This sharing of information will benefit all land managers by ensuring the availability of up-to-date information on management techniques and knowledgeable contacts. Please contact the Office of Natural Lands Management for an ESA publication list. It will contain the date of the latest revision to each ESA. Please refer to the abstract number when ordering ESA's. The abstract is a compilation of available information and is not an endorsement of particular practices or products. Element Name: BIDENS BIDENTOIDES (Nutt.) Britt. (Asteraceae) Element Code: PDAST18070 Preparer: Alfred E. Schuyler Common Name: Bur-marigold Description: Habit: annual glabrous herb up to 1 m tall. Stem: purplish or green, simple or branched. Leaves: opposite, narrowly ovate, up to 18 cm long, with long attenuate petioles and acuminate tips, coarsely serrate, sometimes incised or lobed near base. Inflorescence: heads erect, elliptic or oblong, terminating main and axillary shoots. Outer bracts 3-5, leaf-like, narrowly obovate, up to 6 cm long. Inner bracts 4-8, narrowly elliptic, 1.6 cm long, yellowish and conspicuously striate. Flowers: ray flowers inconspicuous or lacking. Disc flowers up to 6 mm long, 4 or 5 lobed, yellow, glabrous or with scattered hairs on the tube. Fruits: achenes narrowly obtriangular, up to 1.3 cm long, with fine nerves and copious short ascending hairs. Two marginal achenial awns very slender, up to 9 mm long (occasionally 1 or 2 shorter medial awns also present), with fine ascending barbs. Chromosomes: Roberts (1982) reports 2n=48 and the occurrence of meiotic irregularities (i.e., multivalents and univalents) in Hudson River populations. The base number of Bidens is considered to be X=12, which would make B. bidentoides a tetraploid. Related species also have 2n=48 (Roberts, 1982). Distinctions From Related Species: Bidens bidentoides is most likely to be confused with B. connata Muhl. and B. eatonii Fern., both of which occur in similar habitats. Where their ranges overlap with B. bidentoides, the shorter and stouter achenial awns of B. connata and B. eatonii usually have downward protruding (instead of ascending) barbs. Achenes of the latter species lack hairs or they occur sparingly instead of copiously as in B. bidentoides. Plants of B. bidentoides in the Chesapeake Estuary have been described (Blake, 1929) as B. mariana Blake based on differences in leaf shape, length of inflorescence bracts, achenes, and awns, and hairs on the disc flowers. Roberts (1982) found that these differences were not as discrete as indicated by Blake. His data from enzyme electrophoresis indicates that plants from the Hudson River are genetically about equally similar to plants of the Chesapeake and Delaware drainages in allelic composition. Habitat: Bidens bidentoides is endemic to fresh to brackish portions of tidal rivers in the Hudson, Raritan, Delaware, and Chesapeake estuaries in the states of New York, New Jersey, Pennsylvania, Delaware, and Maryland. It occurs in the middle to upper portion of the intertidal zone on firm substrates consisting of sands, gravels, or mud-covered sands and gravels (Ferren and Schuyler, 1980). The plants usually occur in scattered stands and are associated with Amaranthus cannabinus, Bidens laevis, Cyperus bipartitus, Eleocharis obtusa, Juncus acuminatus, Lindernia dubia, Ludwigia palustris, Polygonum punctatum, Scirpus pungens, Scirpus smithii, Sium suave, and Zizania aquatica. Plants of B. bidentoides growing lower in the intertidal zone become dwarf and prostrate (as described by Nutall, 1841), and have blunter less serrate leaves than plants growing higher in the intertidal zone. This species often occurs in habitats that have been disturbed by humans (Schuyler, 1986) such as road banks and places where concrete slabs were scattered to prevent erosion. Here it is associated with plants characteristic of disturbed habitats such as Ambrosia artemisiifolia, Chenopodium ambroisioides, and Plantago major. Biology/Ecology: Bidens bidentoides flowers late in the season from August through October. Reproduction is presumably sexual with offspring developing from both cross-pollinated and self-pollinated plants. Roberts (1982) reported that plants from the Hudson, Delaware, and Chesapeake estuaries have very similar electrophoretic phenotypes with high levels of fixed heterozygosity. He further states that the allozyme differences between these tetraploid populations are mostly due to different allelic combinations that were probably generated through occasional recombinational events between the two genomes and promoted by inbreeding (Roberts, 1982). The upward barbs on the achenial awns of B. bidentoides probably facilitate dispersal in the intertidal zone (Ferren and Schuyler, 1980). If the barbs protruded downwards, as they usually do in other species of Bidens, the achenes might become attached to litter or animals and become stranded in or transported to places where conditions may not be beneficial to the offspring's survival. Determination of Element Occurrence (EO) Quality: Bidens bidentoides occurs at numerous sites in the Hudson (Mitchell and Sheviak, 1981), Delaware (Schuyler and Ferren, 1980), and Chesapeake (Cooley, pers. comm., 1989) estuaries. In the Raritan Estuary, it was recently reported (Roberts, 1982) at one site on the South River. Despite the numerous extant sites for B. bidentoides in the Hudson and Delaware estuaries, its range has become constricted in both. In the Hudson, Muenscher (1937) reported B. bidentoides downstream to Mile Point 35 while Buckley and Ristich (1976) failed to find it below Mile Point 55 in a later survey. Along the Delaware River, Ferren and Schuyler (1980) could not relocate sites below central Philadelphia and Camden in Pennsylvania and New Jersey. In Delaware, however, it has recently been located (Naczi, pers. comm., 1989) at two sites along the Delaware River. Plants of B. bidentoides are variable in height ranging from a few centimeters to nearly a meter. This variation probably is related to the tidal water regime rather than habitat degradation. Plants in disturbed habitats are often vigorous and produce abundant fruits. Threats: Habitat destruction such as dumping dredge spoil, adding landfill, building dikes, and bulkheading probably were responsible for eliminating B. bidentoides from previously known sites in the Delaware estuary (Ferren and Schuyler, 1980). Water quality which was extremely poor in the Delaware River in the vicinity of Philadelphia during the mid-20th Century (Albert, 1988; Kiry, 1974) may also have contributed to site depletions. Habitat destruction appears to be the greatest threat to B. bidentoides today. Water quality has undergone considerable improvement during the latter half of the 20th Century (Albert, 1988). Land Protection Specifications: The upland-wetland transition area and the intertidal zone of fresh to brackish rivers should be protected from extreme human disturbances such as those given in the previous section. The occurrence of vigorous plants at disturbed sites indicates that B. bidentoides can tolerate some human disturbance and may even benefit from it to some extent. Recovery Potential: Fruits of B. bidentoides appear to be adapted for dispersal near the parent plants. The upwardly barbed awns make long distance transport by animals less likely. Therefore recovery may not occur at depleted sites. At partially depleted sites, recovery potential presumably would be high if the plants are vigorous and the factors responsible for depletion are mitigated. Biological Monitoring Needs: Monitor population sizes and search for new populations. Biological Monitoring Procedures: Periodic visits to known populations should be made to record fluctuations in population size and searches for new populations should be conducted. Biological Monitoring Programs: Key people who are searching for and recording information on B. bidentoides are E. Kiviat for the Hudson Estuary, D. B. Snyder and A. E. Schuyler for the Delaware Estuary, and G. Cooley for the Chesapeake Estuary. Research Needs: We need to know the limit of tolerance of B. bidentoides to various degrees of human disturbance and to determine if depleted sites can be restored with or without human intervention. Summary of Stewardship Needs: Bidens bidentoides is an intertidal endemic of the Hudson, Raritan, Delaware, and Chesapeake estuaries. Although presently known from numerous sites, its range has become constricted in the Hudson and Delaware estuaries. Habitat destruction appears to be the cause for range constriction although water pollution may also be a factor. Vigorous plants occur at sites that have been disturbed by humans to some extent. It is recommended the populations be monitored. Research needs should focus on the tolerance of B. bidentoides to various degrees of human disturbance and the recovery potential of depleted sites. Bibliography for Bidens bidentoides (Nutt.) Britt.: Albert, R.C. 1988. The Historical Context of Water Quality Management for the Delaware Estuary. Estuaries 11(2): 99-107. Blake, S.F. 1929. A New Estuarine Bidens from Chesapeake Bay. Rhodora 31: 87-90. Broome, C.R., A.O. Tucker, J.L. Reveal & N.H. Dill. 1979. Rare and Endangered Vascular Plant Species in Maryland. U.S. Fish and Wildlife Service, Newton Corner. vii + 64 pp. Buckley, E.H. & S.S. Ristich. 1976. Distribution of Rooted Vegetation in the Brackish Marshes and Shallows of the Hudson Estuary. Paper 20, Fourth Symposium on Hudson River Ecology Held at Bear Mountain, New York, The Hudson River Environmental Society, Inc., 30 pp. Cooley, G. 1989. Maryland Natural Heritage Program, Annapolis, personal communication. Fassett, N.C. 1928. The Vegetation of the Estuaries of Northeastern North America. Proc. Boston Soc. Nat. Hist. 39(3): 73-130. Fernald, M.L. 1950. Gray's Manual of Botany. 8th ed. American Book Co., New York. lxiv + 1632 pp. Ferren, W.R., Jr. 1976. Aspects of the Intertidal Zones, Vegetation, and Flora of the Maurice River System, New Jersey. Bartonia No.44: 58-67. Ferren, W.R., Jr. & A.E. Schuyler. 1980. Intertidal Vascular Plants of River Systems near Philadelphia. Proc. Acad. Nat. Sci. Philadelphia 132: 86-120. Gleason, H.A. 1952. The New Britton and Brown Illustrated Flora of the Northeastern United States and Adjacent Canada. The New York Botanical Garden, New York. 3 v. Gleason, H.A. & A. Cronquist. 1963. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. D. Van Nostrand Co., Inc., Princeton. li + 810 pp. Kiry, P.R. 1974. An Historical Look at the Water Quality of the Delaware River Estuary to 1973. Contr. Dept. Limnol. Acad. Nat. Sci. Philadelphia No. 4, vi + 135 pp. McVaugh, R. 1958a. Flora of the Columbia County Area, New York. New York State Mus. Bull. No. 360, 400 pp. McVaugh, R. 1958b. Index, Appendix to the Flora of the Columbia County Area, New York. New York State Mus. Bull. No. 360A, 401-433 pp. Mitchell, R.S. & C.J. Sheviak. 1981. Rare Plants of New York State. New York State Mus. Bull. No. 445, viii + 96 pp. Muenscher, W.C. 1935. A Biological Survey of the Mohawk-Hudson Watershed. VII. Aquatic Vegetation of the Mohawk Watershed. Suppl. 24th Annu. Rep., 1934, New York State Conserv. Dept. Biol. Surv. No. 9: 228-229. Muenscher, W.C. 1937. A Biological Survey of the Lower Hudson Watershed. VII. Aquatic Vegetation of the Lower Hudson Area. Suppl. 26th Annu. Rep., 1936, New York State Conserv. Dept. Biol. Surv. No. 11:231-248. Naczi, R.F.C. 1989. University of Michigan, Ann Arbor, personal communication. NJNHP. 1989a. Element Occurrence Summaries. New Jersey Natural Heritage Program, Trenton. NJNHP. 1989b. State Ranking Forms. New Jersey Natural Heritage Program, Trenton. Nuttall, T. 1840. Descriptions of New Species and Genera of Plants in the Natural Order of the Compositae, Collected in a Tour across the Continent to the Pacific, a Residence in Oregon, and a Visit to the Sandwich Islands and Upper.California, during the Years 1834 and 1835. Trans. Amer. Philos. Soc., n.s., 7: 283-453. Reveal, J.L. & C.R. Broome. 1981. Minor Nomenclatural and Distributional Notes on Maryland Vascular Plants with Comments on the State's Proposed Endangered and Threatened Species. Castanea 46(1): 50-82. Reveal, J.L. & C.R. Broome. 1982. Comments on Maryland`s Proposed Endangered and Threatened Vascular Plants. Castanea 47(2): 191-200. Roberts, M.L. 1982. Systematic Studies of North American Bidens Section Bidens (Compositae). Ph.D. Dissertation, Ohio State University, Columbus. Schuyler, A.E. 1986. Rare Plants of the Delaware Estuary in Pennsylvania. Pages 156-162 in S. K. Majumdar, F. J. Brenner, and A. F. Rhoads, eds. Endangered and Threatened Species Programs in Pennsylvania and Other States: Causes, Issues and Management. The Pennsylvania Academy of Science, Easton. Sherff, E.E. 1937. The Genus Bidens. Field Mus. Nat. Hist., Bot. Ser. 16, Parts 1 and 2, 709 pp. Sherff, E.E. & E.J. Alexander. 1955. Compositae-Heliantheae-Coreopsidinae (Bibliography by H. W. Rickett). N. Amer. Fl. Ser. 2, Part 2, 190 pp. Snyder, D.B. & V.E. Vivian. 1981. Rare and Endangered Vascular Plant Species in New Jersey. U. S. Fish and Wildlife Service, Newton Corner. viii + 98 pp. Svenson, H.K. 1925. Notes on Some Plants of Eastern New York. Rhodora 26: 221-222. Svenson, H.K. 1935. Rare Plants from the Estuary of the Hudson River. Torreya 35(5): 117-125. Tatnall, R.R. 1946. Flora of Delaware and the Eastern Shore. The Society of Natural History of Delaware, Wilmington. xxvi + 313 pp. Tucker, A.O., N.H. Dill, C.R. Broome, C.E. Phillips & M.J. Maciarello. 1979. Rare and Endangered Vascular Plant Species in Delaware. U.S. Fish and Wildlife Service, Newton Corner. x + 89 pp. Wiegand, K.M. 1899. Some Species of Bidens found in the United States and Canada. Torrey Bot. Club 26(8): 399-422. Wiegman, P.G. 1979. Rare and Endangered Vascular Plant Species in Pennsylvania. U.S. Fish and Wildlife Service, Newton Corner. 94 pp.