Name:
Senecio triangularis Herbaceous Vegetation
Reference:
Western Ecology Working Group of...
Description:
This association has large gaps in its documented range, occurring in the alpine/subalpine of Colorado and reported again in the mountains of Montana, eastern Oregon and northward into Alberta. This broadly distributed wetland type occurs in small and often linear patches. In Montana and Oregon this type has been well-documented as a riparian stringer of high-gradient, ephemeral, first- or second-order streams; water tables are at the surface throughout the summer. This type also occurs as a species-rich herb meadow on fluvial, residual and colluvial landforms, many of which are subject to snow avalanches. Its documented elevation range in Montana-Alberta is from 1225 to 2181 m (4020-7150 feet). All substrates are apparently relatively medium- to coarse-textured and well-drained. However, all these seemingly disparate environments are subirrigated, with oxygenated water through most of the growing season. The vegetation is characterized by a dense herbaceous layer dominated by <i>Senecio triangularis</i>. Graminoids are a minor component, with <i>Poa alpina, Phleum alpinum, Juncus drummondii, Trisetum spicatum, Elymus glaucus, Glyceria striata (= Glyceria elata)</i>, and <i>Carex disperma</i> the reported species. Shrubs are virtually absent; only <i>Ribes</i> spp. associated with wetlands are present in trace amounts. The diagnostic forb <i>Senecio triangularis</i> is 100% constant and almost always the dominant, the only recorded exceptions being <i>Chamerion</i> spp. (= <i>Epilobium</i> spp.) which may increase markedly following disturbance. Other moderate- to high-constancy forbs indicative of wet-site conditions include <i>Trollius laxus, Parnassia fimbriata, Mimulus lewisii, Veratrum viride, Equisetum arvense, Thalictrum occidentale, Geum macrophyllum, Arnica cordifolia</i>, and <i>Ranunculus</i> spp. Species more associated with the diverse forb meadow condition include <i>Allium schoenoprasum, Arnica mollis, Angelica arguta, Castilleja rhexiifolia, Castilleja miniata, Chamerion angustifolium (= Epilobium angustifolium), Erigeron peregrinus, Epilobium</i> spp. (including <i>Epilobium ciliatum, Epilobium anagallidifolium (= Epilobium alpinum</i>)), and <i>Valeriana sitchensis</i>.
Accession Code:
VB.CC.32576.CEGL001987
Plot-observations of this Community Concept:
0
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