Ribes americanum
Author: P. Mill.

American currant

Grossulariaceae (Currant Family)

Close up of Ribes americanum by Crystal Strouse.
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Close up of Ribes americanum by Crystal Strouse.
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Ranks and Status

Global rank: G5
State rank: S2
Federal protection status: None
State protection status: None

[+] Description and Phenology

Ribes americanum by Barbara Alongi.
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General description: Unarmed shrubs, leaves suborbicular, 3-5 lobed, 3-8 cm long, glabrate above and yellow gland-dotted below. Hypanthium campanulate, hairy, tawny to greenish-white.  Sepals 4-5 mm long, greenish-white. Petals 2-3 mm long, white. Berries 6-10 mm in diameter, black (Ackerfield 2015).

Look Alikes: The yellow glands on the underside of the leaves are quite distinctive.

Phenology: Flowers from mid-May through June, and retains fruits through early September.

[+] Herbarium Photos

Images of Ribes americanum housed at the Colorado State University Herbarium.

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[+] Habitat

Habitat of Ribes americanum by Crystal Strouse.
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In Colorado, this species is found in shady places along streams and in moist meadows at lower elevations along the Front Range (Ackerfield 2015). Associated species include: Salix amygdaloides, S. exigua, Populus deltoides, P. angustifolia, Typha latifolia, Symphoricarpos occidentalis, S. rotundifolius, Ribes aureum, Rosa woodsia, Prunus virginiana, Solidago serotinoides, and abundant exotic weeds such as Bromus tectorum, Breea arvensis, Linaria vulgaris, Melilotus officinale, M. alba, Thlaspi arvense, Verbascum thapsus, Dipsacus fullonum, Lonicera tatarica. Also found at one location with the non-native Crack willow (Salix x. fragilis) and little other vegetation (Colorado Natural Heritage Program occurrence records 2017).

Elevation Range: 4,921 - 6,516 feet (1,500 - 1,986 meters)

[+] Distribution

Distribution of Ribes americanum in Colorado according to mapped land ownership/management boundaries (CNHP 2017, COMaP).
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Distribution of Ribes americanum in Colorado.
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Colorado endemic: No
Global range: This species is found in all of the northeastern United States, north thorough most of Canada, south through the Virginias, west through all the mid-western States, and also found in Montana south through Colorado and New Mexico (USDA NRCS 2017).
State range: In Colorado this species has been documented in Araphoe, Douglas, El Paso, Jefferson, and Larimer counties.

[+] Threats and Management Issues

Infestations of numerous invasive weeds is a concern due to their potential to dominate the few known sites at the exclusion of R. americanum. All sites are also vulnerable to hydrologic alteration, herbicide spraying, and human disturbance and destruction of habitat. Recreational use is a concern at some locations. Colorado climate scenarios for 2050 suggest temperature will increase by 3-7 F and precipitation may decrease or increase.  The impact to any given rare plant habitat is likely to vary.  Long-term monitoring that includes weather and soil moisture data is critical to understanding climate impacts.

[+] References

    • Ackerfield, J. 2015. Flora of Colorado. Brit Press, Botanical Research Institute of Texas, Fort Worth, TX. 818 pp.
    • Colorado Natural Heritage Program and the Geospatial Centroid. 2017. The Colorado Ownership and Protection Map (COMaP). Colorado State University, Ft. Collins, CO.
    • Great Plains Flora Association. 1986. Flora of the Great Plains. University Press of Kansas, Lawrence, KS. 1402 pp.
    • Harrington, H. D. 1954. Manual of the Plants of Colorado. Sage Books, Denver, CO. 666 pp.
    • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
    • USDA, Natural Resources Conservation Service, PLANTS Database [USDA PLANTS]. http://plants.usda.gov/. Accessed 2017.
    • Weber, W. A. and R. C. Wittmann. 2012. Colorado Flora, Eastern Slope, A Field Guide to the Vascular Plants, Fourth Edition. Boulder, Colorado. 555 pp.

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