Genus names beginning with O:
46 genera
134 species
22 subspecies and varieties
134 species
22 subspecies and varieties
Show only taxa with photos
Obtusifolium (1 species)
Ocellularia (1 species)
Ochrolechia (20 species)
Octospora (1 species)
Odonticium (1 species)
Odontites (1 species)
Odontoschisma (3 species)
Oemleria – osoberry (1 species)
Oemleria – Indian plum (1 species)
Oenanthe – oenanthe (1 species)
Oenanthe – water-parsley (1 species)
Oenothera – evening-primrose (8 species)
Oenothera – gaura (8 species)
Oenothera – oenothera (8 species)
Oligoporus (13 species)
Olsynium – purple-eyed grass (1 species)
Olsynium – grass-widow (1 species)
Omphaliaster (1 species)
Omphalina (2 species)
Onnia (3 species)
Onobrychis – sainfoin (1 species)
Ononis (1 species)
Onopordum – cotton-thistle (1 species)
Onygena (1 species)
Opegrapha (8 species)
Ophiocordyceps (2 species)
Ophioglossum – adder's-tongue (1 species)
Ophioparma (3 species)
Oplopanax (1 species)
Opuntia – pricklypear cactus (3 species)
Oreocarya – oreocarya (4 species)
Oreopteris – mountain fern (1 species)
Oreostemma – mountain-crown (1 species)
Origanum – wild marjoram (1 species)
Ornithogalum – ornithogale (1 species)
Ornithogalum – star-of-Bethlehem (1 species)
Orobanche – broomrape (1 species)
Orphniospora (1 species)
Orthilia – one-sided wintergreen (1 species)
Orthocarpus – owl-clover (5 species)
Oryzopsis – ricegrass (1 species)
Osmorhiza – sweet-cicely (4 species)
Osmorhiza – sweet-root (4 species)
Osteina (2 species)
Otidea (8 species)
Ovulinia (1 species)
Oxalis – lady's-sorrel (6 species)
Oxalis – oxalis (6 species)
Oxalis – wood-sorrel (6 species)
Oxybasis – goosefoot (4 species)
Oxyporus (4 species)
Oxyria – mountain sorrel (1 species)
Oxytheca – oxytheca (1 species)
Oxytheca – puncturebract (1 species)
Oxytropis – crazyweed (3 species)
Oxytropis – locoweed (3 species)
Oxytropis – oxytrope (3 species)
Ozomelis – mitrewort (3 species)
Ozomelis – ozomelis (3 species)
