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Illicium contains about 40–45 species with only one species, I. verum, currently of significant commercial importance. The two species of Illicium native to Florida were discovered by Europeans one year apart, in 1765 and 1766, but were thought to represent the same species at the time. Illicium floridanum was later described by Ellis in 1770 and I. parviflorum was described by Ventenat in 1799. A lectotype is designated for I. floridanum.
Seaweeds (macroalgae) accumulate heavy metals from seawater and can therefore serve as biological monitors of marine pollution. In this paper, we present data on the tissue chemistry of seaweeds from the area of Callahan Mine, an intertidal copper and zinc mine in Brooksville, ME, USA, abandoned in the 1970s and now designated as a Superfund site. The mine is located on the Goose Pond estuary, which drains into the ocean via a tidal waterfall at Goose Falls. Seaweed tissue samples from this estuary had the same relative concentrations of metals as had been reported previously in water samples from this location, with Zn > Cu > Pb > Cd. Ascophyllum nodosum, the most common macroalgal species in the area, had comparatively high levels of all four metals in samples from Goose Pond itself, while samples from Goose Falls tended to have substantially lower metal concentrations statistically indistinguishable from samples collected in nearby unpolluted sites. At Goose Falls, where seaweed diversity was highest, Fucus distichus subsp. evanescens tended to accumulate the highest levels of Zn, Cu, Pb, and Cd. We discuss the implications of these results for the Callahan Mine environment and, more generally, for using seaweeds as biological monitors of metal pollution in coastal Maine. In an online appendix, we also provide historical and modern floristic data on the seaweeds of the Callahan Mine. The floristic and tissue chemistry data are baseline information which may be useful for the future assessment and remediation of the mine.
We conducted a hand pollination experiment to test the effects of supplemental pollen and pollen identity on subsequent reproductive success in three American wildflower species: Chamaecrista fasciculata, Gaillardia pulchella and Salvia coccinea. These species are commonly used in ecological restoration plantings and vary in pollination syndrome and compatibility system. We hypothesized that for all three species, treatments that supplemented pollen would yield greater fruit and seed set. Plants were germinated in a closed greenhouse until flowering, then divided into three treatments: “control”, with no supplemental pollen added; “self”, with supplemented self-pollen; and “outcross”, with supplemented outcross pollen. Treated flowers were bagged and allowed to develop to mature fruit stage, and any resulting fruits and seeds were counted and weighed. Results varied between species. Outcross C. fasciculata flowers had significantly higher fruit set than self or control treated flowers, whereas S. coccinea flowers showed no difference in fruit set between treatments. For S. coccinea, self and outcross flowers tended to produce heavier and more abundant seeds than control flowers, although results were not significant at the p=0.05 level. Gaillardia pulchella produced no fruits or seeds in any treatment. Our results highlight the importance of considering the breeding system and the pollination needs of plants chosen for prairie restorations. If wild pollinators or genetically diverse plant populations are not initially abundant, plantings may need to be monitored or possibly re-seeded for long-term establishment success.
Patterns of morphological variation within the North American annual hemiparasite, Melampyrum lineare, are reexamined in this study of its four varieties: M. lineare var. americanum, M. lineare var. latifolium, M. lineare var. lineare, and M. lineare var. pectinatum. Data were collected from 248 herbarium specimens drawn from the species' geographic range in Canada and the United States and included 45 vegetative, reproductive, and ecological characters. Each variety was found to have a broader distribution than previously reported, which expanded the area of known sympatry among the varieties to include most of the species' range. Multivariate analysis of variance revealed statistically significant differences in morphology among the four varieties (p<0.001 in all cases). However, linear discriminant analysis of morphological data showed a continuum of variation and accurately identified the taxonomic variety of individual specimens only 44–75% of the time. Moreover, principal component analysis of continuous morphological variables failed to uncover partitions of the data that would support alternative circumscriptions of subspecific taxa. A chi-squared contingency test to determine if varietal determinations depended on soil-moisture level failed to find evidence supporting such a conclusion (p=0.121). Results show that morphological variation observed in this species cannot be divided into reliably diagnosable groups. While ecotypes are common in Eurasian Melampyrum species and are explained in part by seasonal variation, no common garden experiments to determine how abiotic and biotic conditions affect phenotype have been conducted using M. lineare. Ongoing molecular phylogeographic study of this species may provide alternative metrics for characterizing the diversity of this wide-ranging species.