Prenanthes altissima - (image 1 of 7)
Taxonomy
Family: Asteraceae
Habitat
Sandy or rocky woods.
Associates
Acer saccharum, Aster cordifolius, Aster macrophyllus, Carex pensylvanica, Dentaria laciniata, Fagus grandifolia, Geranium maculatum, Hamamelis virginiana, Hepatica acutiloba, Polystichum acrostichoides, Quercus alba, Solidago caesia, Tilia americana, Viburnum acerifolium.
Distribution
Manitoba and Quebec south.
Morphology
Erect herbaceous perennial, from 2-7' tall. Leaves alternate, petiolate to sessile or clasping; shape highly variable, ranging from ovate to traingular, or variously lobed, margin irregularly dentate. Flowers greenish white; pappus straw-colored; heads mostly with 5 flowers, rarely 6; principle phyllaries (bracts) fewer than 7 (usually 5). Achenes columnar, not noticeably flattened.
Notes
Flowers mid September to early October
Wetland indicator: Facultative Upland
The stems of Prenanthes spp. exude a milky sap when broken. Most other species in this genus have about 8 phyllaries.
References
Peterson, R. T. and M. McKenney. 1996. A Field Guide to Wildflowers:
Northeastern and North-Central North America.
Houghton Mifflin Company. Boston, MA
Swink, F. and G. Wilhelm. 1994. Plants of the Chicago Region.
Indiana Academy of Science. The Morton Arboretum. Lisle, Illinois.
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Michael Hough © 2005 |