Since I have been unable to locate a full and recent list of state legality regarding plants of the Ribes genus, I compiled my own comprehensive list. Like the laws themselves, this list is dynamic so please contact me if any of the information here is out of date. Please check with your local extension office for confirmation before getting involved with the Ribes genus in any regard.

Summarized: Ribes plants really are forbidden fruit to some people. Residents of New Hampshire, North Carolina and West Virginia are completely out of luck as those states enforce a statewide ban on all Ribes species. Delaware, Massachusetts, New Jersey and Rhode Island enforce a permit system. Most other states ban Ribes cultivars that are not resistant to the White Pine Blister Rust (WPBR) pathogen but below is the complete breakdown.

All the sources provided are from state legislature, extension offices or state universities.

State:
Alabama

• No Restrictions Found
• http://forums.gardenweb.com/forums/load/alabgard/msg0510591428253.html?8

Alaska

• No Restrictions Found

Arizona

• No Restrictions Found

Arkansas

• No Restrictions Found

California

• No Restrictions Found

Colorado

• No Restrictions Found

Connecticut

• No Restrictions Found
• http://www.ct.gov/caes/cwp/view.asp?a=2823&q=377656

Delaware

• Black currant Prohibited
  Permit required for all others
• http://regulations.delaware.gov/AdminCode/title3/800/803.shtml#P2_20

Florida

• No Restrictions Found

Georgia

• No Restrictions Found

Hawaii

• No Restrictions Found

Idaho

• No Restrictions Found

Illinois

• No Restrictions Found

Indiana

• No Restrictions Found

Iowa

• No Restrictions Found

Kansas

• No Restrictions Found

Kentucky

• No Restrictions Found

Louisiana

• No Restrictions Found

Maine

• “European Black Currant, Ribes nigrum prohibited state-wide
  The sale, transportation, further planting or possession of plants of the genus Ribes (commonly) known as currant and gooseberry plants, including cultivated, wild, or ornamental sorts is prohibited in the following Counties in the State of Maine, to wit: York, Cumberland, Androscoggin, Kennebec, Sagadahoc, Lincoln, Knox, Waldo, Hancock, and parts of Oxford, Franklin, Somerset, Piscataquis, Penobscot, Aroostook, and Washington”
• http://www.maine.gov/dacf/mfs/forest_health/quarantine_information.html

Maryland

• No Restrictions Found
• https://extension.umd.edu/growit/fruit-profiles/getting-started-small-fruit

Massachusetts

• Black Currant Prohibited
• Permit required for others except in extensive quarantine areas
• http://www.mass.gov/eea/docs/agr/legal/regs/330-cmr-9-00.pdf
• Check the quarantine list!

Michigan

• Black currant Prohibited
• All others allowed
• http://www.legislature.mi.gov/(S(fnhfaj45izgf1055pho2eajl))/mileg.aspx?page=GetObject&objectname=mcl-act-313-of-1929

Minnesota

• No Restrictions Found

Mississippi

• No Restrictions Found

Missouri

• No Restrictions Found

Montana

• No Restrictions Found

Nebraska

• No Restrictions Found

Nevada

• No Restrictions Found

New Hampshire

• All Ribes spp. Prohibited
• http://www.gencourt.state.nh.us/rsa/html/XIX-A/227-K/227-K-6.htm

New Jersey

• 2. The possession or movement of plant cultivars and hybrids of European Black Currant (Ribes nigrum L.) into or within New Jersey is only allowed under special permit issued by the Department.
• 3. The possession or movement of red currant and gooseberry plants (Ribes sp. and Grossularia sp.) is allowed into or within New Jersey except the following municipalities, constituting a protective area: Montague, Sandyston, Walpack and Vernon Townships in Sussex County; West Milford, Ringwood Borough and Wanaque Township in Passaic County, and Jefferson Township in Morris County.
• 4. Currant plants and gooseberry plants other than the European Black Currant (Ribes nigrum L.) may be moved into and within all other points in New Jersey by complying with the general requirements of the New Jersey Department of Agriculture for the movement of nursery stock (N.J.S.A. 4:7-16 et seq.).
• http://www.nj.gov/agriculture/divisions/pi/prog/plantpest.html

New Mexico

• No Restrictions Found

New York

• No ban on disease resistant plants
• http://www.fruit.cornell.edu/mfruit/gooseberries.html

North Carolina

• All Ribes spp. Prohibited
• http://www.cals.ncsu.edu/specialty_crops/publications/other_docs/NCRegulations_Currants_Gooseberries.doc
• http://www.ncagr.gov/plantindustry/plant/disease/48A-04.htm

North Dakota

• No Restrictions Found

Ohio

• The current Ohio law (Regulation AG-71-85.01) to
  suppress and control White Pine Blister Rust Disease is
  as follows:
• (A) The European black currant, Ribes nigrum L. or any
  variety of this species is hereby declared to be a public
  nuisance, and it shall be unlawful for any person to
  possess, transport, plant, propagate, sell, or offer for
  sale, plants, roots, scions, seeds, or cuttings of these
  plants in this state.
• (B) Recognized varieties, e.g., “Consort” produced by the
  hybridization of Ribes nigrum L. or a variety thereof
  with a resistant or immune species, known to be immune
  or highly resistant to the White Pine Blister Rust
  fungus, (Cronartium ribicola, Fischer) are exempt from
  the restrictions imposed by paragraph (A) above.
  Note: Ohio law does not prohibit the planting of red
  currants or gooseberries within the state.
• http://ohioline.osu.edu/hyg-fact/3000/pdf/3205.pdf

Oklahoma

• No Restrictions Found

Oregon

• No Restrictions Found

Pennsylvania

• No ban enforced
• http://extension.psu.edu/plants/gardening/fphg/gooseberries-currants/legal-restrictions

Rhode Island

• Black currant Prohibited
• Permit required for all others
• http://www.dem.ri.gov/pubs/regs/regs/agric/pinebls2.pdf

South Carolina

• No Restrictions Found

South Dakota

• No Restrictions Found

Tennessee

• No Restrictions Found

Texas

• No Restrictions Found

Utah

• No Restrictions Found

Vermont

• No Restrictions Found
• http://extension.umass.edu/fruitadvisor/ne-small-fruit-management-guide/currants-and-gooseberries

Virginia

• Non-disease resistant Black Currants prohibited
• All others allowed
• http://pubs.ext.vt.edu/438/438-107/438-107.html#L6

Washington

• No Restrictions Found

West Virginia

• All Ribes spp. Prohibited
• http://www.wvagriculture.org/images/Plant_Industries/WV_White_Pine_Blister_Rust_Quarantine.pdf

Wisconsin

• No Restrictions Found

Wyoming

• No Restrictions Found