Cannabis Leaves and Cuttings Fall Outside the Criminal-Law Concept of a Drug

STS 47/2026, of 28 January (cassation appeal 3204/2023), addresses a question that directly affects the defence in cannabis cultivation and possession cases: whether cannabis leaves and cuttings fall within the criminal-law concept of a toxic drug or narcotic. The Chamber's answer is no, and the doctrine it lays down is relevant to any proceedings in which the prosecution rests on that kind of plant material.

Background and subject of the cassation appeal

The public prosecutor appealed in cassation against an acquittal on a public-health offence under Article 368 of the Criminal Code. The acquittal had rested on the finding that the plant material seized — cannabis leaves and cuttings — did not have the legal status of a drug, so the conduct was not a criminal offence. The prosecutor argued that the interpretation was unduly narrow and that the concept of cannabis should be extended to cover that material. The Supreme Court dismissed the appeal and confirmed the acquittal.

The framework of the 1961 Single Convention

The starting point of the Chamber's reasoning is the 1961 Single Convention on Narcotic Drugs, an international instrument that forms part of Spanish law and to which the case law refers in order to define cannabis. That instrument defines cannabis as "the flowering or fruiting tops of the hemp plant" and includes resin, but expressly excludes seeds and leaves not attached to the flowering tops. The Chamber holds that domestic courts cannot disregard that normative definition without a legislative instrument amending or extending it. To apply it is a requirement of the principle of legality.

The legality principle as a limit on extensive interpretation

The Chamber states explicitly that extending the criminal concept of cannabis beyond the framework established in the Single Convention — by including leaves or cuttings that the Convention excludes — would breach the principle of legality enshrined in Article 25 of the Spanish Constitution and the principle of legal certainty. Criminal law cannot punish conduct that falls outside the elements of the offence, even if from a botanical or toxicological standpoint the material might be associated with the plant. What matters is whether the material seized fits the legal definition, not the scientific one. This reasoning blocks extensive interpretations and insulates the doctrine against challenges by the prosecution.

Criminal and administrative consequences: a relevant distinction

The Supreme Court notes that exclusion from the criminal offence does not mean impunity in all cases. Possession of cannabis leaves or cuttings may be subject to an administrative penalty under citizens' security legislation, if the conditions are met. What cannot happen is that the conduct is treated as a criminal offence against public health when the only material seized falls outside the normative concept of a drug. The Chamber thus draws a clear line between the criminal and the administrative wrong, a line that matters for both prosecution and defence.

Practical criterion for the defence in cannabis cases

The doctrine in this judgment acts as a filter at the investigation stage: if the material seized consists exclusively of leaves or cuttings without flowering tops, the defence can and should argue that the conduct is not a criminal offence from the provisional classification onwards. This prevents the proceedings from advancing to trial on the basis of facts that, under Supreme Court case law, do not constitute the offence under Article 368 of the Criminal Code. A botanical expert report may be decisive in establishing the exact nature of the material and thereby consolidating the argument that no offence was committed. The ruling also closes the door to prosecutions that seek to equate non-floral plant material with the substances expressly covered by international conventions.