| Abbrev | Name | Spec | Type | Locality |
|---|---|---|---|---|
| XD | XIN-DONG[1281]; | TR.AE | CHN | |
| XEMA | XEMA[1281]; | TR.DR | S | MEX |
| XEMA1 | XEMA-1[1281]; | TR.DR | S | MEX |
| XEMA2 | XEMA-2[1281]; | TR.DR | S | MEX |
| XEMA3 | XEMA-3[1281]; | TR.DR | S | MEX |
| XEQ88 | XEQUIJEL-88[1281] | TR.AE | S | GTM |
| XF | XIN-FENG[1281]; | TR.AE | CHN | |
| XHY | XIANG-HUA-BAI-YU-HUA[1281]; | TR.AE | CHN | |
| XIAN8 | XIAN-8[1281]; | TR.AE | CHN | |
| XIAN9 | XIAN9[1281]; | TR.AE | CHN | |
| XIFONG | XIFONG[1281]; | TR.AE | CHN | |
| XJ | XELAJU-66[1281]; | TR.AE | S | GTM |
| XJ66 | XELAJU-66[1281] | TR.AE | S | GTM |
| XJ91 | XELAJU-91[1281] | TR.AE | S | GTM |
| XV | XEVORA[1281]; | TR.AE | PRT | |
| XY1 | XIAN-YANG-1[1281]; | TR.AE | CHN | |
| Y | YAQUI[144][1281]; | TR.AE | S | MEX |
| Y48 | YAQUI-48[1281]; | TR.AE | S | MEX |
| Y50 | YAQUI-50[1281]; | TR.AE | S | MEX |
| Y50E | YAQUI-50-ENANO[1281]; | TR.AE | S | MEX |