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Saxifrage Family

Ecological And Economic Importance



Species in the saxifrage family are important components of certain natural habitats, especially in alpine and arctic tundras, where as many as 7-10 species of Saxifraga can occur in the same local habitat.



Many species in the saxifrage family are grown as ornamentals in horticulture. Various species of native and Eurasian Saxifraga are commonly grown in rock gardens. Some other species native to temperate North America are also sometimes grown in horticulture, including bishop's cap (Mitella spp.), coral bells or alum root (Heuchera spp.), and lace flower or foam-flower (Tiarella spp.). Currants and gooseberries that flower prominently are also grown as ornamental shrubs in gardens, including Ribes alpinum, R. americanum, R. speciosum, and other species. Hydrangeas are also cultivated as flowering shrubs, including the Eurasian species, Hydrangea paniculata and H. macrophylla.

The fruits of currants and gooseberries are important agricultural crops in some areas, particularly in Europe and Asia. Currants and gooseberries are not, however, widely grown in North America, because they are an alternate host for white pine blister rust (Cronartium ribicola), an important, introduced fungal pathogen of white pine (Pinus strobus) and other five-needled pines, which are economically important species of trees.

The most common species of currants and gooseberries in cultivation are the red-fruited currant (Ribes rubrum; there is also a white-fruited variety of this species) of Europe, the black-fruited currant (R. nigrum) of Eurasia, and the gooseberry (R. grossularia) of Eurasia, which can have red, yellow, green, or white fruits, depending on the variety. Native North American species with abundant, edible fruits include the wild black currant (Ribes americanum) and wild gooseberry (Ribes hirtellum). The species of Ribes that are known as currants have smooth fruits and stems, and their flowers and fruits occur in elongate inflorescences known as racemes. The gooseberries have prickly or spiny stems and fruits, and their flowers and fruits occur in a solitary fashion. Most currants and gooseberries are dried as a means of preservation, or are used to make jams, jellies, pies, and wine.


Resources

Books

Judd, Walter S., Christopher Campbell, Elizabeth A. Kellogg, Michael J. Donoghue, and Peter Stevens. Plant Systematics: A Phylogenetic Approach. 2nd ed. with CD-ROM. Suderland, MD: Sinauer, 2002.

Klein, R.M. The Green World. An Introduction to Plants and People. New York: Harper and Row, 1987.


Bill Freedman

KEY TERMS

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Alternate host

—Many pathogens and parasites must infect two or more different species in order to complete their reproductive cycle. If one of those alternate hosts can be eliminated from the ecosystem, then disease transmission can be interrupted, and the other host can be productive and healthy.

Boreal

—This refers to the conifer-dominated forest that occurs in the sub-Arctic, and gives way to tundra at more northern latitudes.

Montane

—This refers to the conifer-dominated forest that occurs below the alpine tundra on mountains.

Perfect

—In the botanical sense, this refers to flowers that are bisexual, containing both male and female reproductive parts.

Raceme

—An elongate inflorescence, consisting of individual flowers arranged along a linear axis, with the oldest ones being closest to the bottom.

Tundra

—This is a treeless ecosystem that occurs at high latitude in the Arctic and Antarctic, and at high altitude on mountains.

Additional topics

Science EncyclopediaScience & Philosophy: Jean-Paul Sartre Biography to Seminiferous tubulesSaxifrage Family - Species In North America, Ecological And Economic Importance