Skaneateles Conservation Area/Invasive species/Rubus

<< State-regulated and other highly invasive plants at the SCA

Rubus caesius (European Dewberry)

European Dewberry (Rubus caesius) has not been widely reported in North America. In fact the Invasive Plant Atlas of the United States shows it present in only two counties (based on iMapInvasives observations): Green County, WI (2) and Onondaga County, NY (2).

The first vouchered Rubus caesius specimen in New York was collected in Tioga county in 1923, and resides at Baily Hortoreum along with specimens collected in Madison County in 2017. The first Onondaga County specimen was collected in 1951 and is in the Vascular Plant Herbarium at the State Museum, where there is also specimen from Yates County collected in 1973.

New York Counties where "research grade" iNaturalist observations of Rubus caesius have been made are Cayuga, Onondaga, and Ontario.

Invasiveness ranking for Rubus caesius (European Dewberry)

The NYNHP Rank for Rubus caesius is High (Ecological) and Equal outcome (Socio-economic). The New York State Invasive Species Tier for Rubus caesius in the FL-PRISM is 3

As of August 2021, an invasiveness ranking for Rubus caesius had not been included in the published Non-Native Plant Assessments for New York State, nor is it regulated by New York State law.

The Invasive Species Policy Committee of Cornell Botanic Gardens (previously Cornell Plantations), in their Policy on the use of Non-Native Plants In Cornell Botanic Gardens’ Accessioned Collections, includes Rubus caesius in their list of "Plant species that are considered moderately to highly invasive to natural areas in the central Finger Lakes region."

The Finger Lakes Native Plant Society also places Rubus caesius on its "Level 2 (moderately bad)" Invasive Plants list for the Cayuga Lake basin as determined by Cornell field botanist F. Robert Wesley.

The Capitol Region PRISM (Partnership for Regional Invasive Species Management) has placed Rubus caesius on its Tier 1 (Early Detection/Prevention) list of Invasive Terrestrial Plants. The Finger Lakes PRISM places in Tier 3, while New York State places it in Tier 4. The state now ranks it as Highly Invasive.

Observations of Rubus caesius (European Dewberry) at the SCA

The following photographs and corresponding iNaturalist observations of Rubus caesius were made at or very near the Skaneateles Conservation Area. Click on images to enlarge and read details on Wikimedia Commons or on the "iNat obs" links to view the corresponding observations at iNaturalist.

• Rubus caesius, Shepard Settlement, 19 May 2011. iNat obs
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Lateral leaflets often have large shallow proximal lobes, giving them a "mitten" shape.

• Rubus caesius, Shepard Settlement, 31 May 2011. iNat obs
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Young primocanes are glaucus.

• Rubus caesius, Shepard Settlement, 07 Jul 2015. iNat obs
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• Rubus caesius, Shepard Settlement, 08 Jul 2015. iNat obs
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• Rubus caesius, Shepard Settlement, 06 Aug 2019. iNat obs
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• Rubus caesius, Skaneateles Conservation Area, 27 Aug 2019. Photos by Ken Burdick. iNat obs
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