Gattungen assoziierter Organismen: Oberna [6 Taxa], Obryzum [1 Taxon], Ocalea [1 Taxon], Ochlandra [15 Taxa], Ochna [53 Taxa], Ochrocarpos [7 Taxa], Ochroconis [6 Taxa], Ochrolechia [17 Taxa], Ochroma [5 Taxa], Ochrosia [1 Taxon], Ochthocosmus [15 Taxa], Ocimum [124 Taxa], Ocotea [430 Taxa], Octoknema [1 Taxon], Octomeria [1 Taxon], Odina [13 Taxa], Odocoileus [96 Taxa], Odontadenia [3 Taxa], Odontesthes [2 Taxa], Odontites [83 Taxa], Odontoglossum [12 Taxa], Odontonema [5 Taxa], Odontotermes [9 Taxa], Odontotrema [1 Taxon], Oedaleus [1 Taxon], Oedemium [3 Taxa], Oedocephalum [2 Taxa], Oedogonium [7 Taxa], Oenanthe [23 Taxa], Oenocarpus [26 Taxa], Oenothera [128 Taxa], Oidiodendron [11 Taxa], Oidium [106 Taxa], Ojibwaya [2 Taxa], Olax [15 Taxa], Oldenlandia [55 Taxa], Oldfieldia [1 Taxon], Olea [720 Taxa], Oleander [1 Taxon], Oleandra [1 Taxon], Olearia [9 Taxa], Oliganthes [22 Taxa], Olinia [37 Taxa], Olivea [3 Taxa], Olmedia [3 Taxa], Olpidiopsis [36 Taxa], Olpidium [29 Taxa], Olyra [82 Taxa], Omalotheca [2 Taxa], Ombrophila [1 Taxon], Omega [18 Taxa], Ommatospora [2 Taxa], Ommatosporella [11 Taxa], Omphalea [14 Taxa], Omphalina [1 Taxon], Omphalodes [1 Taxon], Omphalospora [1 Taxon], Onagra [1 Taxon], Oncidium [44 Taxa], Oncinotis [19 Taxa], Oncoba [17 Taxa], Oncopodium [7 Taxa], Oncorhynchus [2 Taxa], Oncosperma [21 Taxa], Oncosporomyces [19 Taxa], Onobrychis [163 Taxa], Onoclea [2 Taxa], Ononis [76 Taxa], Onopordon [39 Taxa], Onopordum [48 Taxa], Onosma [19 Taxa], Onychium [1 Taxon], Oospora [3 Taxa], Opegrapha [82 Taxa], Operculina [11 Taxa], Ophiobolus [14 Taxa], Ophioceras [7 Taxa], Ophiociliomyces [4 Taxa], Ophioglossum [5 Taxa], Ophionectria [1 Taxon], Ophiopogon [3 Taxa], Ophiorrhiza [3 Taxa], Ophiostoma [5 Taxa], Ophiostomella [1 Taxon], Ophiurus [4 Taxa], Opilia [6 Taxa], Oplismenus [89 Taxa], Opopanax [2 Taxa], Opuntia [112 Taxa], Orbignya [16 Taxa], Orbilia [16 Taxa], Orcadia [1 Taxon], Orchis [12 Taxa], Oreamnos [3 Taxa], Orectochilus [1 Taxon], Orectogyrus [1 Taxon], Oredoxa [4 Taxa], Oreochloa [1 Taxon], Oreocnide [1 Taxon], Oreodoxa [1 Taxon], Oreomyrrhis [4 Taxa], Oreopanax [11 Taxa], Origanum [55 Taxa], Orinebius [1 Taxon], Orinocoa [1 Taxon], Orites [1 Taxon], Ormiscodes [1 Taxon], Ormocarpum [7 Taxa], Ormosia [31 Taxa], Ornithidium [1 Taxon], Ornithodoros [1 Taxon], Ornithogalum [104 Taxa], Ornithoglossum [2 Taxa], Ornithopus [1 Taxon], Orobanche [105 Taxa], Orobus [1 Taxon], Orocharis [1 Taxon], Orontium [1 Taxon], Oropetium [3 Taxa], Oropogon [1 Taxon], Oroxylon [2 Taxa], Oroxylum [6 Taxa], Orromyces [1 Taxon], Orthaga [1 Taxon], Orthantha [2 Taxa], Orthezia [18 Taxa], Orthilia [2 Taxa], Orthobellus [2 Taxa], Orthoclada [2 Taxa], Orthodon [1 Taxon], Orthopappus [1 Taxon], Orthosanthus [5 Taxa], Orthosiphon [6 Taxa], Orthrosanthus [4 Taxa], Oryctanthus [7 Taxa], Oryctes [2 Taxa], Oryctolagus [3247 Taxa], Oryza [1064 Taxa], Oryzopsis [24 Taxa], Osbeckia [6 Taxa], Osmanthus [103 Taxa], Osmia [1 Taxon], Osmorhiza [28 Taxa], Osmoxylon [3 Taxa], Osmunda [17 Taxa], Osphronemus [1 Taxon], Ossaea [8 Taxa], Osteospermum [12 Taxa], Ostodes [1 Taxon], Ostrinia [1 Taxon], Ostrya [18 Taxa], Ostryoderris [4 Taxa], Oswaldoa [21 Taxa], Osyridocarpos [36 Taxa], Osyris [57 Taxa], Othius [1 Taxon], Othonna [6 Taxa], Otiorhynchus [1 Taxon], Otites [15 Taxa], Otochilus [1 Taxon], Otophora [1 Taxon], Otospermum [2 Taxa], Otthia [1 Taxon], Ottochloa [4 Taxa], Otyria [1 Taxon], Oudemansiella [10 Taxa], Ougeinia [12 Taxa], Ouratea [76 Taxa], Ourisia [12 Taxa], Ovidia [1 Taxon], Ovis [2511 Taxa], Ovulariopsis [3 Taxa], Oxalis [132 Taxa], Oxandra [75 Taxa], Oxya [1 Taxon], Oxyanthus [32 Taxa], Oxybaphus [3 Taxa], Oxycoccus [2 Taxa], Oxydothis [3 Taxa], Oxygonum [2 Taxa], Oxypetalum [5 Taxa], Oxyria [9 Taxa], Oxyspora [2 Taxa], Oxystelma [3 Taxa], Oxytellus [1 Taxon], Oxytenanthera [4 Taxa], Oxytropis [29 Taxa], Oyedaea [22 Taxa]