This IRS manual may give a principle to consider on this question (I am not a tax lawyer -- so consult a tax attorney to be sure what applies to your situation).
25.18.1.2 (03-04-2011) Property Rights and Federal Taxation
Federal law determines how property is taxed, but state law determines whether, and to what extent, a taxpayer has "property" or "rights to property" subject to taxation. Aquilino v. United States, 363 U.S. 509 (1960); Morgan v. Commissioner, 309 U.S. 78 (1940). Accordingly, federal tax is assessed and collected based upon a taxpayer's state created rights and interest in property.
25.18.1.2.4 (03-04-2011) Tax Assessment and Collection under Community Property Laws
For income tax purposes, if spouses file separate returns, each spouse is taxed on 50% of the total community property income regardless of which spouse acquired the income. Poe v. Seaborn, 282 U.S. 101 (1930). In addition, each spouse is taxed upon 100% of his or her separate property income. Community property may also affect basis in property.
Source: https://www.irs.gov/irm/part25/irm_25-018-001
