| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| HYRO3 | Hydranthelium rotundifolium (Michx.) Pennell | Bacopa rotundifolia | Scrophulariaceae
|
| HYCA | Hydrastis canadensis L. | goldenseal | Ranunculaceae
|
| HYDRA2 | Hydrastis L. | hydrastis | Ranunculaceae
|
| HYVE3 | Hydrilla verticillata (L. f.) Royle | waterthyme | Hydrocharitaceae
|
| HYDRI | Hydrilla L.C. Rich. | hydrilla | Hydrocharitaceae
|
| HYCO12 | Hydrocharis cordifolia Nutt. | Limnobium spongia | Hydrocharitaceae
|
| HYMO6 | Hydrocharis morsus-ranae L. | common frogbit | Hydrocharitaceae
|
| HYSP6 | Hydrocharis spongia Bosc | Limnobium spongia | Hydrocharitaceae
|
| HYDRO8 | Hydrocharis L. | hydrocharis | Hydrocharitaceae
|
| HYCA2 | Hydrochloa caroliniensis Beauv. | Luziola fluitans | Poaceae
|
| HYNY | Hydrocleys nymphoides (Humb. & Bonpl. ex Willd.) Buch. | waterpoppy | Limnocharitaceae
|
| HYDRO6 | Hydrocleys L.C. Rich. | hydrocleys | Limnocharitaceae
|
| HYAM | Hydrocotyle americana L. | American marshpennywort | Apiaceae
|
| HYAS4 | Hydrocotyle asiatica L. | Centella asiatica | Apiaceae
|
| HYAU2 | Hydrocotyle australis Coult. & Rose | Hydrocotyle prolifera | Apiaceae
|
| HYBO | Hydrocotyle bonariensis Comm. ex Lam. | largeleaf pennywort | Apiaceae
|
| HYBO3 | Hydrocotyle bowlesioides Mathias & Constance | largeleaf marshpennywort | Apiaceae
|
| HYCA13 | Hydrocotyle canbyi Coult. & Rose | Hydrocotyle prolifera | Apiaceae
|
| HYHI4 | Hydrocotyle hirsuta Sw. | yerba de clavo | Apiaceae
|
| HYMO4 | Hydrocotyle moschata G. Forst. | musky marshpennywort | Apiaceae
|
| HYPR10 | Hydrocotyle prolifera Kellogg | whorled marshpennywort | Apiaceae
|
| HYPU4 | Hydrocotyle pusilla A. Rich. | tropical marshpennywort | Apiaceae
|
| HYRA | Hydrocotyle ranunculoides L. f. | floating marshpennywort | Apiaceae
|
| HYRO4 | Hydrocotyle rotundifolia Lam. | Hydrocotyle sibthorpioides | Apiaceae
|
| HYSIO | Hydrocotyle sibthorpioides Lam. var. oedipoda O. Deg. & Greenw. | Hydrocotyle bowlesioides | Apiaceae
|
| HYSI | Hydrocotyle sibthorpioides Lam. | lawn marshpennywort | Apiaceae
|
| HYUM | Hydrocotyle umbellata L. | manyflower marshpennywort | Apiaceae
|
| HYVEF | Hydrocotyle verticillata Thunb. var. fetherstoniana (Jennings) Mathias | whorled marshpennywort | Apiaceae
|
| HYVET | Hydrocotyle verticillata Thunb. var. triradiata (A. Rich.) Fern. | Hydrocotyle prolifera | Apiaceae
|
| HYVEV | Hydrocotyle verticillata Thunb. var. verticillata | whorled marshpennywort | Apiaceae
|
| HYVE2 | Hydrocotyle verticillata Thunb. | whorled marshpennywort | Apiaceae
|
| HYDRO2 | Hydrocotyle L. | hydrocotyle | Apiaceae
|
| HYMO10 | Hydrogrimmia mollis (Bruch & Schimp. in B.S.G.) Loeske | Grimmia mollis | Grimmiaceae
|
| HYAF | Hydrolea affinis Gray | Hydrolea uniflora | Hydrophyllaceae
|
| HYCO7 | Hydrolea corymbosa J.F. Macbr. ex Ell. | skyflower | Hydrophyllaceae
|
| HYOV | Hydrolea ovata Nutt. ex Choisy | ovate false fiddleleaf | Hydrophyllaceae
|
| HYQU | Hydrolea quadrivalvis Walt. | waterpod | Hydrophyllaceae
|
| HYSP | Hydrolea spinosa L. | spiny false fiddleleaf | Hydrophyllaceae
|
| HYUN | Hydrolea uniflora Raf. | oneflower false fiddleleaf | Hydrophyllaceae
|
| HYDRO3 | Hydrolea L. | false fiddleleaf | Hydrophyllaceae
|
| HYLA11 | Hydromystria laevigata (Humb. & Bonpl. ex Willd.) Hunziker | Limnobium laevigatum | Hydrocharitaceae
|
| HYST | Hydromystria stolonifera G.F.W. Mey. | Limnobium laevigatum | Hydrocharitaceae
|
| HYAQ | Hydrophila aquatica (L.) House | Crassula aquatica | Crassulaceae
|
| HYDR2 | Hydrophila drummondii (Torr. & Gray) House | Crassula drummondii | Crassulaceae
|
| HYDR3 | Hydrophila drummondii sensu (Torr. & Gray) House p.p. | Crassula longipes | Crassulaceae
|
| HYVA2 | Hydrophila vaillantii sensu House, non (Willd.) Roth | Crassula saginoides | Crassulaceae
|
| HYAP | Hydrophyllum appendiculatum Michx. | great waterleaf | Hydrophyllaceae
|
| HYBR11 | Hydrophyllum brownei Kral & Bates | Brown's waterleaf | Hydrophyllaceae
|
| HYCA3 | Hydrophyllum canadense L. | bluntleaf waterleaf | Hydrophyllaceae
|
| HYCAA | Hydrophyllum capitatum Dougl. ex Benth. var. alpinum S. Wats. | alpine waterleaf | Hydrophyllaceae
|
| HYCAC | Hydrophyllum capitatum Dougl. ex Benth. var. capitatum | ballhead waterleaf | Hydrophyllaceae
|
| HYCAT | Hydrophyllum capitatum Dougl. ex Benth. var. thompsonii (M.E. Peck) Constance | Thompson's waterleaf | Hydrophyllaceae
|
| HYCA4 | Hydrophyllum capitatum Dougl. ex Benth. | ballhead waterleaf | Hydrophyllaceae
|
| HYCO18 | Hydrophyllum congestum Wieg. | Hydrophyllum fendleri var. albifrons | Hydrophyllaceae
|
| HYFEA | Hydrophyllum fendleri (Gray) Heller var. albifrons (Heller) J.F. Macbr. | white waterleaf | Hydrophyllaceae
|
| HYFEF | Hydrophyllum fendleri (Gray) Heller var. fendleri | Fendler's waterleaf | Hydrophyllaceae
|
| HYFE | Hydrophyllum fendleri (Gray) Heller | Fendler's waterleaf | Hydrophyllaceae
|
| HYMA | Hydrophyllum macrophyllum Nutt. | largeleaf waterleaf | Hydrophyllaceae
|
| HYOCW | Hydrophyllum occidentale (S. Wats.) Gray var. watsonii Gray | Hydrophyllum occidentale | Hydrophyllaceae
|
| HYOC | Hydrophyllum occidentale (S. Wats.) Gray | western waterleaf | Hydrophyllaceae
|
| HYTE | Hydrophyllum tenuipes Heller | Pacific waterleaf | Hydrophyllaceae
|
| HYVIA | Hydrophyllum virginianum L. var. atranthum (Alexander) Constance | Hydrophyllum virginianum | Hydrophyllaceae
|
| HYVI | Hydrophyllum virginianum L. | Shawnee salad | Hydrophyllaceae
|
| HYVI8 | Hydrophyllum viridulum G.N. Jones | Hydrophyllum tenuipes | Hydrophyllaceae
|
| HYDRO4 | Hydrophyllum L. | waterleaf | Hydrophyllaceae
|
| HYVE7 | Hydrothyria venosa J. L. Russell | | Peltigeraceae
|
| HYDRO9 | Hydrothyria J. L. Russell | hydrothyria | Peltigeraceae
|
| HYCA16 | Hydrotrida caroliniana (Walt.) Small | Bacopa caroliniana | Scrophulariaceae
|
| HYCL | Hyeronima clusioides (Tul.) Muell.-Arg. | cedro macho | Euphorbiaceae
|
| HYERO | Hyeronima Allemao | hyeronima | Euphorbiaceae
|
| HYFLO | Hygroamblystegium fluviatile (Hedw.) Loeske var. orthocladon (P. Beauv.) Crum et al. | Hygroamblystegium tenax var. tenax | Amblystegiaceae
|
| HYFLO2 | Hygroamblystegium fluviatile (Hedw.) Loeske var. ovatum Grout | Hygroamblystegium fluviatile | Amblystegiaceae
|
| HYFL5 | Hygroamblystegium fluviatile (Hedw.) Loeske | streamside hygroamblystegium moss | Amblystegiaceae
|
| HYIRS | Hygroamblystegium irriguum (Hook. & Wils.) Loeske var. spinifolium (Schimp.) M�nk. | Hygroamblystegium tenax var. spinifolium | Amblystegiaceae
|
| HYIR | Hygroamblystegium irriguum (Hook. & Wils.) Loeske | Hygroamblystegium tenax var. tenax | Amblystegiaceae
|
| HYMA6 | Hygroamblystegium macroneuron Grout | Donrichardsia macroneuron | Amblystegiaceae
|
| HYNO3 | Hygroamblystegium noterophilum (Sull. & Lesq. in Sull.) Warnst. | hygroamblystegium moss | Amblystegiaceae
|
| HYOR3 | Hygroamblystegium orthocladon (P. Beauv.) Loeske | Hygroamblystegium tenax var. tenax | Amblystegiaceae
|
| HYTES | Hygroamblystegium tenax (Hedw.) Jenn. var. spinifolium (Schimp.) Jenn. | hygroamblystegium moss | Amblystegiaceae
|
| HYTET | Hygroamblystegium tenax (Hedw.) Jenn. var. tenax | hygroamblystegium moss | Amblystegiaceae
|
| HYTE6 | Hygroamblystegium tenax (Hedw.) Jenn. | hygroamblystegium moss | Amblystegiaceae
|
| HYVA3 | Hygroamblystegium varium (Hedw.) M�nk. | Amblystegium varium | Amblystegiaceae
|
| HYGRO5 | Hygroamblystegium Loeske | hygroamblystegium moss | Amblystegiaceae
|
| HYLA14 | Hygrobiella laxifolia (Hook.) Spruce | | Cephaloziaceae
|
| HYGRO3 | Hygrobiella Spruce | | Cephaloziaceae
|
| HYAL3 | Hygrohypnum alpestre (Hedw.) Loeske | hygrohypmum moss | Amblystegiaceae
|
| HYAL4 | Hygrohypnum alpinum (Lindb.) Loeske | alpine hygrohypnum moss | Amblystegiaceae
|
| HYBE2 | Hygrohypnum bestii (Ren. & Bryhn in Ren.) Broth. | Best's hygrohypnum moss | Amblystegiaceae
|
| HYCL2 | Hygrohypnum closteri (Aust.) Grout | hygrohypnum moss | Amblystegiaceae
|
| HYCO13 | Hygrohypnum cochlearifolium (Vent. ex De Not.) Broth. | hygrohypnum moss | Amblystegiaceae
|
| HYDI4 | Hygrohypnum dilitatum (Wils.) Loeske | Hygrohypnum molle | Amblystegiaceae
|
| HYDU2 | Hygrohypnum duriusculum (De Not.) Jamieson | hygrohypnum moss | Amblystegiaceae
|
| HYEU2 | Hygrohypnum eugyrium (Schimp. in B.S.G.) Loeske | hygrohypnum moss | Amblystegiaceae
|
| HYEU3 | Hygrohypnum eumontanum Crum et al. | Hygrohypnum montanum | Amblystegiaceae
|
| HYLUP | Hygrohypnum luridum (Hedw.) Jenn. ssp. pseudomontanum (Kindb.) Wijk & Marg. | Hygrohypnum luridum | Amblystegiaceae
|
| HYLUE | Hygrohypnum luridum (Hedw.) Jenn. var. ehlei (Arnell) Wijk & Marg. | Hygrohypnum luridum | Amblystegiaceae
|
| HYLUJ | Hygrohypnum luridum (Hedw.) Jenn. var. julaceum (Schimp. in B.S.G.) Podp. | Hygrohypnum luridum | Amblystegiaceae
|
| HYLUS | Hygrohypnum luridum (Hedw.) Jenn. var. subsphaericarpon (Brid.) C. Jens. in Podp. | Hygrohypnum luridum | Amblystegiaceae
|
| HYLU5 | Hygrohypnum luridum (Hedw.) Jenn. | hygrohypnum moss | Amblystegiaceae
|
| HYMI8 | Hygrohypnum micans (Mitt.) Broth. | hygrohypnum moss | Amblystegiaceae
|
| HYMO8 | Hygrohypnum molle (Hedw.) Loeske | hygrohypnum moss | Amblystegiaceae
|