- Radish
- Randia aculeata
- Ranunculus abortivus
- Ranunculus aconitifolius
- Ranunculus acris
- Ranunculus aquatilis
- Ranunculus arvensis
- Ranunculus asiaticus
- Ranunculus auricomus
- Ranunculus bulbosus
- Ranunculus ficaria
19.Rapeseed
- Rauvolfia tetraphylla
- Redcurrant
- Reseda alba
- Reseda lutea
- Reseda luteola
- Reseda phyteuma
- Retama monosperma
- Rhamnus alaternus
- Rhamnus cathartica
- Rheum rhabarbarum
- Rheum rhaponticum
- Rheum ribes
- Rhexia mariana
- Rhexia virginica
- Rhizophora mangle
- Rhodiola rosea
- Rhododendron ferrugineum
- Rhododendron hirsutum
- Rhododendron maximum
- Rhododendron viscosum
- Rhubarb
- Rhus copallina
- Rhus coriaria
- Rhus glabra
- Rhynchospora alba
- Rhynchostylis retusa
- Ribes alpinum
- Ribes cynosbati
- Ribes grossularia
- Ribes nigrum
- Ribes oxyacanthoides
- Ribes rubrum
- Ribes uva-crispa
- Ricinus
- Ricinus communis
- Rivina humilis
- Robinia pseudoacacia
- Rosa canina
- Rosa carolina
- Rosa gallica
- Rosa sempervirens
- Rosa villosa
- Roselle (plant)
- Rosemary
- Rosmarinus officinalis
- Rostraria cristata
- Rotala ramosior
- Rubia peregrina
- Rubia tinctorum
- Rubus arcticus
- Rubus caesius
- Rubus canadensis
- Rubus chamaemorus
- Rubus hispidus
- Rubus idaeus
- Rubus moluccanus
- Rubus odoratus
- Rubus parvifolius
- Rubus saxatilis
- Rudbeckia hirta
- Rudbeckia laciniata
- Rudbeckia triloba
- Ruellia tuberosa
- Rumex acetosa
- Rumex acetosella
- Rumex crispus
- Rumex maritimus
- Rumex obtusifolius
- Rumex patientia
- Rumex pulcher
- Rumex scutatus
- Ruppia maritima
- Ruscus aculeatus
- Ruscus hypoglossum
- Ruta graveolens
- Ruta patavina
- Rutabaga
- Rye
Ranunculus ficaria
- Lesser Celandine (Ranunculus ficaria)
- A buttercup-like plant unrelated to the greater celandine, one of the poppy family
- Usage: treating piles
- Harmful effects: rare cases of hepatitis after use.<wiki/List_of_medicinal_plants#cite_note-58">
- Chamomile or camomile (Asteraceae family)
- Usage: Vaginal steaming
- There are many species called chamomile, each with some level of distinct chemical properties. Despite this, chamomile is routinely treated as a single herb and proscribed as such.<wiki/List_of_medicinal_plants#cite_note-UMMRomanchamomile-59"><wiki/List_of_medicinal_plants#cite_note-UMMGermanchamomile-60"> The two most common species are:
- Two species are most commonly used, Matricaria nobilis (Roman chamomile) and M. chamomilla (German chamomile)<wiki/List_of_medicinal_plants#cite_note-theherbbook-7">
Rubia tinctorum
- Madder root (Rubia tinctorum)
- Used as: an "astringent diuretic, emmenagogue", and claimed to be good for many conditions, including alkaline urine, diarrhea, inflammation, wounds, broken bones, fever, and many others.<wiki/List_of_medicinal_plants#cite_note-theherbbook-7"><wiki/List_of_medicinal_plants#cite_note-149"><wiki/List_of_medicinal_plants#cite_note-150"><wiki/List_of_medicinal_plants#cite_note-151"> There is no evidence to support the use of madder root for any of these conditions.<wiki/List_of_medicinal_plants#cite_note-madder-152"> The root is used in Ayurveda and Hildegard medicine. Madder root is also used for dyeing fabrics.
- Harmful effects: May cause cancer, birth defects, and miscarriages.<wiki/List_of_medicinal_plants#cite_note-madder-152"> It can also make urine, saliva, perspiration, tears, and breast milk turn red. One wonders if happier root would be any better. An extract of madder root, used as a food coloring in Japan, was found to cause liver cancer in rats.<wiki/List_of_medicinal_plants#cite_note-153">
Rosmarinus officinalis
- Rosemary (Rosmarinus officinalis)
- In TCM: mí dié xiāng (迷迭香)
- Used in: vaginal steaming
- Claimed to: solve digestion problems, heartburn, flatulence, liver and gallbladder problems, lack of appetite, gout, coughing, headaches, high blood pressure, and age-related memory loss. No such effects have been proven.<wiki/List_of_medicinal_plants#cite_note-WebMDRosemary-184"><wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- Beneficial effects:
- Lab work shows rosemary has antioxidant properties.<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- Studies suggest long-term rosemary use may prevent thrombosis in humans.<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- Studies suggest rosemary may neutralize several foodborne pathogens.<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- One (one, badly designed, and small) study suggests rosemary, if used topically on the head, may help hair regrowth.<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- Two studies (small, aromatherapy, not compared to placebo) suggest it may help reduce stress.<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- Improved speed and accuracy on a test for a study of a sample people when scent was inhaled.<wiki/List_of_medicinal_plants#cite_note-186">
- Contains antioxidants carnosic acid and carnosol .<wiki/List_of_medicinal_plants#cite_note-187"><wiki/List_of_medicinal_plants#cite_note-188"><wiki/List_of_medicinal_plants#cite_note-189"> No proven resulting benefits, however.
- Is a little spicy and smells nice.<wiki/List_of_medicinal_plants#cite_note-WebMDRosemary-184"><wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- Harmful effects:
- Is probably safe if the leaf itself is eaten; is rated as Generally Recognized as Safe in the U.S.;<wiki/List_of_medicinal_plants#cite_note-AmerPregRosemary-190"> the German Commission E has approved it.<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- May impact blood clotting.<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- May impact ACE inhibitors, taken for high blood pressure.<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- Is diuretic .<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- May impact blood-sugar levels.<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- Large quantities of rosemary leaves can cause vomiting, spasms, comas, and pulmonary edema .<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- Large quantities of rosemary leaves may increase menstrual blood-flow and can cause miscarriage and is rated Possibly UnSafe in the U.S. Even while pregnant, however, it is safe to eat as a spice in food.<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185"><wiki/List_of_medicinal_plants#cite_note-191">
- "People with high-blood pressure, ulcers, Crohn's disease, or ulcerative colitis should not take rosemary."<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">
- Rosemary oil may be toxic if consumed orally.<wiki/List_of_medicinal_plants#cite_note-UMMRosemary-185">