The serpentine-substrate effect is well documented for vascular plants, but the literature for bryophytes is limited. The majority of literature on bryophytes in extreme geoedaphic habitats focuses on the use of species as bioindicators of industrial pollution. Few attempts have been made to characterize bryophyte floras on serpentine soils derived from peridotite and other ultramafic rocks. This paper compares the bryophyte floras of both a peridotite and a granite outcrop from the Deer Isles, Hancock County, Maine, and examines tissue elemental concentrations for select species from both sites. Fifty-five species were found, 43 on serpentine, 26 on granite. Fourteen species were shared in common. Twelve species are reported for the first time from serpentine soils. Tissue analyses indicated significantly higher Mg, Ni, and Cr concentrations and significantly lower Ca:Mg ratios for serpentine mosses compared to those from granite. Soil analyses demonstrated significant differences between the two substrates.

Recently dithiol-yne click chemistry and its role in the formation of cross-linked polymer networks and postpolymerization functionalizations has been studied; however, no research has considered this technique to form comb polymers with regular side chains. Here we report the first example of a grafted-through stepgrowth comb polymer via the utilization of dithiol-yne "click chemistry". First, we exhibited the efficacy of this reaction to produce modest-molecular-weight combs (M n = 16 kDa). Second, we displayed the ability to precisely control the length of the side chains of these combs along with the space between the side chains by using various molecular weights of propargylated PEG chains and a variety of alkanedithiol backbone spacers. The primary species of these reactions were macrocyclic comb polymers, with a smaller amount of dithiol-terminated comb polymers.

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