High-spectral resolution reflectance data were acquired in the laboratory for several species of boreal forest and peatland mosses. Feather mosses and lichens (forests), brown mosses (rich fens), and Sphagnum species (bogs and poor fens) were collected from sites in the northern study area (NSA) of the Boreal Ecosystem-Atmosphere Study (BOREAS) near Thompson, Manitoba, and from three peatlands in southeastern New Hampshire. Because mosses are indirect indicators of soil moisture, trace gas flux, and carbon accumulation, these data may enable hyperspectral remote sensing systems, such as the airborne visible and infrared imaging spectrometer and the compact airborne spectrographic imager (AVIRIS) (CASI), as well as future systems such as Lewis and the first New Millennium Project, to infer differences in hydrology and carbon cycling in boreal ecosystems at small spatial scales (<1--900 m2). Mosses exhibit distinctly different spectral characteristics from vascular plants in the visible, near-infrared (NIR) and short-wave infrared (SWIR) regions. In the visible portion of the spectrum, mosses exhibit typical absorption in the blue and red regions but differ from vascular plants in having a green peak reflective of the color (red, brown, or green) of the individual species. The moss reflectance in the NIR spectral region is typically less reflective than the same region in vascular plants and is characterized by strong water absorption features located at approximately 1.00 and 1.20 μm, resulting in pronounced reflectance peaks at approximately 0.85, 1.10, and 1.30 μm (identified as NIR 1, 2, and 3, respectively). The variations in the relative brightness of the three NIR peaks in each of the three groups of mosses (Sphagnum, feather, and brown mosses) are diagnostic and may be indicative of different cellular characteristics. The slope of the NIR plateau as determined by the NIR 3/1 ratio, as well as the shape of the NIR 1 peak and relative dominance of NIR 2, separate the three groups. In addition, the NIR 1 peak in Sphagnum species is marked by a minor absorption feature at 0.85 μm, which is absent in all brown mosses and feather mosses, as well as in vascular plants. Because this absorption feature results in a narrow NIR 1 peak, and the red absorption is also narrow in Sphagnum, the standard normalized difference vegetation index/simple vegetation index ratio (NDVI/VI) methods do not work well in characterizing biomass or greenness. The overall reflectance of mosses in the SWIR region (1.50--250 μm) is lower than that of vascular plants because of the higher water content of the moss tissue. In lichens, reflectance inthis region is higher than either mosses or vascular plants, due likely to tissue dryness. The lichens included in this study are most dissimilar from mosses and vascular plants in the visible portion of the spectrum. ¿ 1997 American Geophysical Union