Tubercles and spines on fruit peel are important commercial traits in cucumber(Cucumis sativus L.). From an ethyl methane sulfonate cucumber mutant library,we discovered a new glabrous mutant that bears no tubercle or spine on fruit peel and fewer and smaller trichomes on the stem and leaves. The new locus is here designated as glabrous2(gl2). Genome sequencing of the mutant and linkage analysis revealed that a non-synonymous mutation in the Csa1G056960 gene rendered the gl2 phenotype. The mutated gene encodes a C-type lectin receptor-like tyrosine protein kinase. This study provides a novel allele for elucidating the genetic basis of wart and trichome development and a new tool for breeding glabrous cucumber varieties. Tubercles and spines on fruit peel are important commercial traits in cucumber (Cucumis sativus L.) From an ethyl methane sulfonate cucumber mutant library, we discovered a new glabrous mutant that bears no tubercle or spine on fruit peel and fewer and smaller trichomes on the stem and leaves. The new locus is here designated as glabrous2 (gl2). Genome sequencing of the mutant and linkage analysis revealed that a non-synonymous mutation in the Csa1G056960 gene rendered the gl2 phenotype. The mutated gene encodes a C-type lectin receptor -like tyrosine protein kinase. This study provides a novel allele for elucidating the genetic basis of wart and trichome development and a new tool for breeding glabrous cucumber varieties.