| Strain name | Breeder | Flowering time | Strain heritage | Feminized |
|---|---|---|---|---|
| Auto Xtremo | Cartel Seeds | 80 | ruderalis / indica / sativa | feminized |
| X | Zamnesia | 74 | mostly sativa | feminized |
| X Æ B-M04 | Humboldt Bred | 65 | indica / sativa | feminized |
| X-15 | Lupos CannaSeed | 65 | indica / sativa | feminized |
| X-18 3/4 Haze | White Buffalo Seed Collective | 90 | indica / sativa | regular |
| X-Berry | Apex Seeds | 52 | mostly indica | feminized |
| X-Dog | Alpine-Seeds | 65 | mostly sativa | regular |
| X-File | Unknown or Legendary | - | mostly indica | regular |
| X-Haze | White Label | 73 | indica / sativa | feminized |
| X-Kunk | Apex Seeds | 56 | mostly sativa | feminized |
| X-Kush | Blue Stone Sanctuary | - | indica | regular |
| X-Kush #1 | Breeder Choice Organisation | 56 | indica | regular |
| X-Kush #2 | Breeder Choice Organisation | 63 | indica | regular |
| X-OH | White Buffalo Seed Collective | 77 | indica / sativa | regular |
| X-TRA CHZ | MTG Seeds | 60 | indica / sativa | regular |
| X-Wing | Unknown or Legendary | - | mostly indica | regular |
| X13 | Unknown or Legendary | - | mostly indica | regular |
| X18 | The Landrace Team | 60 | indica | regular |
| X18 | Tom Hill | 63 | indica | regular |
| X18 Pure Pakistani | Reserva Privada | 60 | indica | feminized |
| Xanadu | Dutchgrown Seeds | 62 | mostly sativa | regular |
| Xanadu | Katsu Seeds | - | indica / sativa | feminized |
| Xanthanite | Ronin Garden | 75 | ruderalis / indica / sativa | feminized |
| Xeddar | All-in Medicinal Seeds | 53 | mostly indica | feminized |
| Xena | Medtree | 65 | mostly sativa | regular |
| Xena | Exotic Genetix | - | unknown | regular |
| Xena OG | South Bay Genetics | 70 | indica / sativa | regular |
| Xenu | Cult Classics Seeds | 63 | indica / sativa | regular |
| Xfile | Mogwai Genetics | 61 | mostly indica | regular |
| Xhale | Elev8 Seeds | 60 | indica / sativa | feminized |
| Xian | Shaolin Genetics | 65 | indica / sativa | regular |
| Xiezhi | Scapegoat Genetics | 63 | unknown | regular |
| Xingu | Maconha Seeds Bank | 55 | mostly indica | feminized |
| XJ-13 | Unknown or Legendary | - | mostly sativa | regular |
| XL Italian Shoes | Cult Classics Seeds | 60 | unknown | feminized |
| Xmas Bud 1979 | Unknown or Legendary | - | mostly indica | regular |
| XmasDuck | Evolve Genetics | 70 | indica / sativa | regular |
| XMEN | Realpotency | 65 | mostly indica | regular |
| Xnine | Smiling Tiger | 63 | mostly indica | regular |
| XO Raspberry Glue | Haute Genetique | 63 | mostly indica | regular |
| Xocolope | Eskobar Seeds | 67 | mostly sativa | regular |
| Xodus #1 | Real Gorilla Seeds | 55 | indica / sativa | feminized |
| XTC OG | Elev8 Seeds | 67 | mostly indica | feminized |
| Xtreme Kush | Xtreme Seeds Co. | 70 | mostly indica | feminized |
| XXX | Ethos Genetics | 60 | indica / sativa | feminized |
| XXX Mints | Black Flag Genetics | 67 | indica / sativa | regular |