• Rosa Linnaeus, 1753
• Rosa aberrans Wolley-Dod accepted as Rosa scabriuscula Winch ex Sm.
• Rosa abietina Gren.
• Rosa abietina Gren. ex H. Christ
• Rosa abietorum Greene
• Rosa abortiva Charb. & Fouill.
• Rosa abscondita Charb.
• Rosa abscondita H. Christ
• Rosa abstenta Déségl.
• Rosa abutalybovii Gadzh.
• Rosa abyssinica R. Br.
• Rosa abyssinica R. Br. ex Lindl.
• Rosa acantha Waitz ex Link
• Rosa acanthina Déségl. & Ozanon accepted as Rosa canina Linnaeus
• Rosa acanthizans Lindstr.
• Rosa accumbens Matsson
• Rosa accurrens Matsson ex Lindstr.
• Rosa accurtaticeps Matsson
• Rosa acharii Billb.
• Rosa acharii Boreau
• Rosa acharii Déségl.
• Rosa achburensis Chrshan.
• Rosa acicularioides Schuette
• Rosa acicularis Lindl.
• Rosa acicularis Rupr. ex Nyman
• Rosa aciculata (Cockerell) Cockerell
• Rosa aciphylla A. Rau
• Rosa aciphylloides (Rouy) Sennen
• Rosa aciphylloides Crép. ex Cottet & Castella
• Rosa acmenodon Matsson
• Rosa acmenophylla Matsson
• Rosa acrotoma Matsson
• Rosa actinodroma Gand. accepted as Rosa canina Linnaeus
• Rosa aculeatior Lindstr.
• Rosa aculeatissima Dum. Cours.
• Rosa acuminata Raf.
• Rosa acuminata Sw. ex Rchb.
• Rosa acuta Crép.
• Rosa acuta Fisch. ex Sweet
• Rosa acutalis Matsson
• Rosa acutantula Matsson
• Rosa acutatula Matsson ex Lindstr.
• Rosa acutiformis Oborný
• Rosa adaugens (Almq.) Lindstr.
• Rosa addita Déségl.
• Rosa adenocalyx Gren. accepted as Rosa canina Linnaeus
• Rosa adenocarpa Greene
• Rosa adenochaeta Koidz. (unaccepted)
• Rosa adenoclada H. Lév.
• Rosa adenoclada Hy
• Rosa adenoclados Dalla Torre & Sarnth.
• Rosa adenodonta Dubovik
• Rosa adenophora Kit.
• Rosa adenophylla Galushko
• Rosa adenophylla Willd.
• Rosa adenosepala Wooton & Standl. (unaccepted)
• Rosa adenotricha Dalla Torre & Sarnth.
• Rosa adjecta Déségl.
• Rosa admista Burnat
• Rosa adscita Déségl.
• Rosa aeduensis Déségl. & Gillot
• Rosa aemoniana Puget ex R. Keller
• Rosa affabilis Vuk.
• Rosa affectata Matsson
• Rosa affinior Gand.
• Rosa affinis A. Rau
• Rosa affinis Gand.
• Rosa affinis Sternb.
• Rosa affinita Puget ex Heinr. Braun
• Rosa afzeliana Fr. accepted as Rosa canina Linnaeus
• Rosa afzeliana Fr. ex Lilj. accepted as Rosa caesia Smith
• Rosa aganodon Matsson
• Rosa aganodonta Matsson ex Lindstr.
• Rosa aginensis Ripart ex Déségl.
• Rosa agraria Ripart ex Déségl.
• Rosa agrestina Crép.
• Rosa agrestina Ripart ex Déségl. accepted as Rosa agraria Ripart ex Déségl.
• Rosa agrestis C.C. Gmel.
• Rosa agrestis Savi
• Rosa agrestis Sw.
• Rosa agustiana Sennen
• Rosa alabukensis Tkatsch.
• Rosa alaica Juz.
• Rosa alampeta Matsson ex Lindstr.
• Rosa alba All.
• Rosa alba Linnaeus
• Rosa alba P. Gaertn., B. Mey. & Scherb.
• Rosa albertii Regel
• Rosa albicans Godet ex Boiss. accepted as Rosa elymaitica Boiss. & Hausskn. ex Boiss.
• Rosa albida Kmet
• Rosa albidula Matsson
• Rosa albiflora Opiz
• Rosa albispinosa Lindstr.
• Rosa albolutescens Ripart ex Déségl. accepted as Rosa canina Linnaeus
• Rosa albolutescens Ripart ex Heinr. Braun
• Rosa alcea Greene (unaccepted)
• Rosa aldersonii Greene accepted as Rosa californica Cham. & Schltdl.
• Rosa aleutensis Crép.
• Rosa alexandrae Buzunova
• Rosa alexeenkoi Crép. ex Juz.