- racemoso, racemose
- racimo, raceme
- radiado, radiate
- radical, radical
- radicante, radicant
- radícula, radicle
- rafe, raphe
- rafidios, raphides
- raíz, root
- raíz central, tap root
- raíz contráctil, pull root
- raíz fúlcrea, prop root
- raíz suculenta, fleshy root
- rama, branch
- ramas del estilo, style-arms
- rameal, ramal, rameous
- ramentáceo, ramentaceous
- ramento, rament
- ramentoso, ramentaceous
- ramificado, branching, ramose
- ramificarse, ramificate
- ramita, twig
- raquilla, rachilla, raquilla
- raquis, rachis
- raramente, rarely
- rastrero, trailing, repent
- rayado, streaked, striped
- rayo, ray
- rayuelos, raylets
- raza, strain
- realzado, flanged
- receptáculo, receptacle
- reclinado, reclinate, reclining
- rectangular, rectangular
- recto, straight
- recurvado, decurved, recurved, upcurved, recurvate
- redondeadamente, roundly
- redondeado, rotundate, rounded
- reducido, reduced, slight
- reduplicado, reduplicate
- reflexo, deflexed, reflexed
- relicto, relic, relict
- rematando en, tipped with
- remoto, remote
- removido, excised
- reniforme, reniform
- renuevo, sobole, surculose
- repando, repand
- replicado, replicate
- replo, replum
- reptante, creeping
- resinoso, resinous
- resupinado, resupinate
- reticulación faveoloide, honey comb reticulation
- reticulado, reticular, reticulate
- reticulado-faveoloide, honey combed-reticulate
- retináculo, retinaculum
- retoño, offshoot
- retraído-doblado, folded-retracted
- retro-, retro-, retrorsely
- retrobarbado, barbellate, ancistrous, retrorsely barbellate
- retrorso, retrorse
- retro-crenado, retrorsely crenate
- retro-serrado, retrorsely serrate
- retuso, retuse
- revoluto, revolute
- ribera, bank
- rígidamente, stiffly
- rígido, stiff
- rímula, rima
- ringente, ringent
- ripario, riparian, actophilous
- ripidio, rhipidium
- rizocárpico, rhizocarpic
- rizóforo, rhizophore
- rizoide, rhizoid
- rlzoma, rhizome
- rizomatoso, rhizomatous
- robusto, robust, stout
- rojizo, reddish
- rojo-pardusco, rufous
- rómbico, rhomboidal, rhombate, rhombic
- romboide, rhomboid
- rórido, dewy, roridous
- rosado, pink, pinkish
- roseta, rosette
- rostelo, rostellum
- rostrado, rostrate, beaked, pointed
- rostro, beak, rostrum, point