| Name | Accession number | Synonym | Species | Habit | Locality |
|---|---|---|---|---|---|
| MASSY | K-6295; PI-44951; CI-5859; AUS-7154 | HYBRIDE-DE-MASSY[39][1446]; | TR.AE | W | FRA |
| MASSY-UNBEGRANNT-UNBEHAART | K-40523 | TR.AE | W | DEU | |
| MASTER,CAN | K-8084 | OTTAWA-520[2331]; RL-28[3116]; | TR.AE | S | CAN |
| MASTER,FRA | K-59502 | TR.AE | W | FRA | |
| MASTER-INVERSABLE | TR.AE | FRA | |||
| MASTER-NT | MASTER,GBR[40]; UC-11569[40]; | TR.AE | W | GBR | |
| MASTER-PIECE | K-41893; PI-278577; PI-321701; AFRC-503 | MASTERPIECE[201][2280]; | TR.AE | W | GBR:England |
| MASTERS-57 | TR.AE | W | GBR | ||
| MASTERS-SQUAREHEAD-II | PI-278567 | TR.AE | W | GBR:England | |
| MASTERS-SQUAREHEAD-MASTER-II | PI-278585 | TR.AE | W | GBR:England | |
| MASTERS-YEOMAN | PI-278592 | TR.AE | W | GBR:England | |
| MASTIFF | X-8504-C-2Y-2M-100M-0Y[3692]; | TR.SE | S | MEX | |
| MA.SUBLETSCHUMICUM | TR.MA | ||||
| MATADOR | HTRI-1578; PI-51686; CI-6656 | WHITE-MATADOR-ROODKOP[233]; | TR.AE | W | NLD |
| MATADOR-ROOD-KOP | TR.AE | NLD | |||
| MATADOR-WIT-KOP | TR.AE | NLD | |||
| MATARCAO | K-58282 | TR.DR | S | ITA | |
| MATCH | K-57594; PI-659590; ERGE-2780 | 643[40]; | TR.AE | W | FRA |
| MATCHBALL | RICP-01C0107409 | TR.AE | W | CZE | |
| MA-TCL | TR.SE | S | MEX |