| Symbol | Scientific name | Common name/Accepted name (for synonyms) | Family |
| HIHO | Hieracium horridum Fries | prickly hawkweed | Asteraceae
|
| HIKAC | Hieracium kalmii L. var. canadense (Michx.) Reveal | Hieracium canadense var. canadense | Asteraceae
|
| HIKAF | Hieracium kalmii L. var. fasciculatum (Pursh) Lepage | Hieracium canadense var. fasciculatum | Asteraceae
|
| HIKA2 | Hieracium kalmii L. | Kalm's hawkweed | Asteraceae
|
| HILA8 | Hieracium lachenalii K.C. Gmel. | common hawkweed | Asteraceae
|
| HILA4 | Hieracium laevigatum Willd. | smooth hawkweed | Asteraceae
|
| HILE2 | Hieracium lemmonii Gray | Lemmon's hawkweed | Asteraceae
|
| HILO | Hieracium longiberbe T.J. Howell | longbeard hawkweed | Asteraceae
|
| HILO2 | Hieracium longipilum Torr. | hairy hawkweed | Asteraceae
|
| HIMA4 | Hieracium �macrostolonum Schneid. | Hieracium flagellare var. cernuiforme | Asteraceae
|
| HIMA3 | Hieracium maculatum Sm. | spotted hawkweed | Asteraceae
|
| HIMA | Hieracium �marianum Willd. (pro sp.) | | Asteraceae
|
| HIME | Hieracium megacephalon Nash | coastalplain hawkweed | Asteraceae
|
| HIMU | Hieracium murorum L. | wall hawkweed | Asteraceae
|
| HIPA2 | Hieracium paniculatum L. | Allegheny hawkweed | Asteraceae
|
| HIPA5 | Hieracium parryi Zahn | Hieracium scouleri var. scouleri | Asteraceae
|
| HIPE2 | Hieracium pennsylvanicum Fries | Hieracium marianum | Asteraceae
|
| HIPIN | Hieracium pilosella L. var. niveum Muell.-Arg. | mouseear hawkweed | Asteraceae
|
| HIPIP | Hieracium pilosella L. var. pilosella | mouseear hawkweed | Asteraceae
|
| HIPI | Hieracium pilosella L. | mouseear hawkweed | Asteraceae
|
| HIPI2 | Hieracium piloselloides Vill. | tall hawkweed | Asteraceae
|
| HIPRD | Hieracium praealtum Vill. ex Gochnat var. decipiens W.D.J. Koch | kingdevil | Asteraceae
|
| HIPR3 | Hieracium praealtum Vill. ex Gochnat | kingdevil | Asteraceae
|
| HIPR | Hieracium pratense Tausch | Hieracium caespitosum | Asteraceae
|
| HIPR2 | Hieracium pringlei Gray | Pringle's hawkweed | Asteraceae
|
| HIRO4 | Hieracium robinsonii (Zahn) Fern. | Robinson's hawkweed | Asteraceae
|
| HIRU | Hieracium rusbyi Greene | Rusby's hawkweed | Asteraceae
|
| HISA4 | Hieracium sabaudum L. | New England hawkweed | Asteraceae
|
| HISCC | Hieracium scabriusculum Schwein. var. columbianum (Rydb.) Lepage | Hieracium canadense var. canadense | Asteraceae
|
| HISCP | Hieracium scabriusculum Schwein. var. perhirsutum Lepage | Hieracium umbellatum | Asteraceae
|
| HISCS3 | Hieracium scabriusculum Schwein. var. saximontanum Lepage | Hieracium umbellatum | Asteraceae
|
| HISCS4 | Hieracium scabriusculum Schwein. var. scabrum (Schwein.) Lepage | Hieracium umbellatum | Asteraceae
|
| HISC8 | Hieracium scabriusculum Schwein. | Hieracium umbellatum | Asteraceae
|
| HISCI | Hieracium scabrum Michx. var. intonsum Fern. & St. John | rough hawkweed | Asteraceae
|
| HISCS | Hieracium scabrum Michx. var. scabrum | rough hawkweed | Asteraceae
|
| HISCT | Hieracium scabrum Michx. var. tonsum Fern. & St. John | rough hawkweed | Asteraceae
|
| HISC | Hieracium scabrum Michx. | rough hawkweed | Asteraceae
|
| HISCA | Hieracium scouleri Hook. var. albertinum (Farr) G.W. Douglas & G.A. Allen | Hieracium cynoglossoides | Asteraceae
|
| HISCG | Hieracium scouleri Hook. var. griseum (Rydb.) A. Nels. | Hieracium cynoglossoides | Asteraceae
|
| HISCN | Hieracium scouleri Hook. var. nudicaule (Gray) Cronq. | Scouler's woollyweed | Asteraceae
|
| HISCS2 | Hieracium scouleri Hook. var. scouleri | Scouler's woollyweed | Asteraceae
|
| HISC2 | Hieracium scouleri Hook. | Scouler's woollyweed | Asteraceae
|
| HISC4 | Hieracium �scribneri Small (pro sp.) | | Asteraceae
|
| HISI | Hieracium siskiyouense M.E. Peck | Hieracium bolanderi | Asteraceae
|
| HITR5 | Hieracium traillii Greene | Hieracium greenii | Asteraceae
|
| HITRG | Hieracium triste Willd. ex Spreng. ssp. gracile (Hook.) Calder & Taylor | Hieracium gracile var. gracile | Asteraceae
|
| HITRF | Hieracium triste Willd. ex Spreng. var. fulvum Hult�n | woolly hawkweed | Asteraceae
|
| HITRG2 | Hieracium triste Willd. ex Spreng. var. gracile (Hook.) Gray | Hieracium gracile var. gracile | Asteraceae
|
| HITRT2 | Hieracium triste Willd. ex Spreng. var. triste | woolly hawkweed | Asteraceae
|
| HITRT | Hieracium triste Willd. ex Spreng. var. tritiforme Zahn | Hieracium triste var. triste | Asteraceae
|
| HITR2 | Hieracium triste Willd. ex Spreng. | woolly hawkweed | Asteraceae
|
| HIUMC | Hieracium umbellatum L. var. canadense (Michx.) Breitung | Hieracium canadense var. canadense | Asteraceae
|
| HIUMS | Hieracium umbellatum L. var. scabriusculum Farw. | Hieracium canadense var. canadense | Asteraceae
|
| HIUM | Hieracium umbellatum L. | narrowleaf hawkweed | Asteraceae
|
| HIUN2 | Hieracium ungavense Lepage | Hieracium robinsonii | Asteraceae
|
| HIVEN | Hieracium venosum L. var. nudicaule (Michx.) Farw. | Hieracium venosum | Asteraceae
|
| HIVE | Hieracium venosum L. | rattlesnakeweed | Asteraceae
|
| HIVU | Hieracium vulgatum Fries | Hieracium lachenalii | Asteraceae
|
| HIWR | Hieracium wrightii (Gray) Robins. & Greenm. | roughstem hawkweed | Asteraceae
|
| HIERA | Hieracium L. | hawkweed | Asteraceae
|
| HIALA | Hierochloe alpina (Sw. ex Willd.) Roemer & J.A. Schultes ssp. alpina | alpine sweetgrass | Poaceae
|
| HIALO | Hierochloe alpina (Sw. ex Willd.) Roemer & J.A. Schultes ssp. orthantha (Sorensen) G. Weim. | alpine sweetgrass | Poaceae
|
| HIALO2 | Hierochloe alpina (Sw. ex Willd.) Roemer & J.A. Schultes var. orthantha (Sorensen) Hult�n | Hierochloe alpina ssp. orthantha | Poaceae
|
| HIAL3 | Hierochloe alpina (Sw. ex Willd.) Roemer & J.A. Schultes | alpine sweetgrass | Poaceae
|
| HIFR | Hierochloe fragrans (Willd.) Roemer & J.A. Schultes | Hierochloe odorata | Poaceae
|
| HIHIA | Hierochloe hirta (Schrank) Borb�s ssp. arctica (J. Presl) G. Weim. | northern sweetgrass | Poaceae
|
| HIHI | Hierochloe hirta (Schrank) Borb�s | northern sweetgrass | Poaceae
|
| HIMA8 | Hierochloe macrophylla Thurb. ex Boland. | Hierochloe occidentalis | Poaceae
|
| HIMO3 | Hierochloe monticola (Bigelow) A.& D. L�ve, non Mez | Hierochloe alpina ssp. orthantha | Poaceae
|
| HINA | Hierochloe nashii (Bickn.) Kaczmarek | Hierochloe odorata | Poaceae
|
| HIOC | Hierochloe occidentalis Buckl. | California sweetgrass | Poaceae
|
| HIODA | Hierochloe odorata (L.) Beauv. ssp. arctica (J. Presl) Tzvelev | Hierochloe hirta ssp. arctica | Poaceae
|
| HIODF | Hierochloe odorata (L.) Beauv. var. fragrans (Willd.) Richter | Hierochloe odorata | Poaceae
|
| HIOD | Hierochloe odorata (L.) Beauv. | vanilla grass | Poaceae
|
| HIOD2 | Hierochloe odorata auct. non (L.) Beauv. p.p. | Hierochloe alpina ssp. alpina | Poaceae
|
| HIOR | Hierochloe orthantha Sorensen | Hierochloe alpina ssp. orthantha | Poaceae
|
| HIPA3 | Hierochloe pauciflora R. Br. | arctic sweetgrass | Poaceae
|
| HIERO | Hierochloe R. Br. | sweetgrass | Poaceae
|
| HIBEB | Hilaria belangeri (Steud.) Nash var. belangeri | curly-mesquite | Poaceae
|
| HIBEL | Hilaria belangeri (Steud.) Nash var. longifolia (Vasey) A.S. Hitchc. | longleaf curly-mesquite | Poaceae
|
| HIBE | Hilaria belangeri (Steud.) Nash | curly-mesquite | Poaceae
|
| HIJA | Hilaria jamesii (Torr.) Benth. | Pleuraphis jamesii | Poaceae
|
| HIMU2 | Hilaria mutica (Buckl.) Benth. | Pleuraphis mutica | Poaceae
|
| HIRI | Hilaria rigida (Thurb.) Benth. ex Scribn. | Pleuraphis rigida | Poaceae
|
| HISW | Hilaria swallenii Cory | Swallen's curly-mesquite | Poaceae
|
| HILAR | Hilaria Kunth | curly-mesquite | Poaceae
|
| HISA | Hillebrandia sandwicensis D. Oliver | aka'aka'aka | Begoniaceae
|
| HILLE | Hillebrandia D. Oliver | hillebrandia | Begoniaceae
|
| HIPA4 | Hillia parasitica Jacq. | tibey trepador | Rubiaceae
|
| HILLI | Hillia Jacq. | hillia | Rubiaceae
|
| HISC6 | Hilpertia scotteri (Zand. & Steere) Zand. | Tortula scotteri | Pottiaceae
|
| HIEQ | Hippeastrum equestre (Aiton) Herb. | Hippeastrum puniceum | Liliaceae
|
| HIPU | Hippeastrum puniceum (Lam.) Kuntze | Barbados lily | Liliaceae
|
| HIPPE | Hippeastrum Herbert | hippeastrum | Liliaceae
|
| HILO3 | Hippobroma longiflora (L.) G. Don | madamfate | Campanulaceae
|
| HIPPO3 | Hippobroma G. Don | hippobroma | Campanulaceae
|
| HIHYA | Hippochaete hyemalis (L.) Bruhin ssp. affinis (Engelm.) W.A. Weber | Equisetum hyemale var. affine | Equisetaceae
|
| HIHY2 | Hippochaete hyemalis (L.) Bruhin | Equisetum hyemale var. affine | Equisetaceae
|
| HILA5 | Hippochaete laevigata (A. Braun) Farw. | Equisetum laevigatum | Equisetaceae
|
| HIVA | Hippochaete variegata (Schleich. ex F. Weber & D.M.H. Mohr) Bruhin | Equisetum variegatum var. variegatum | Equisetaceae
|
| HICA9 | Hippocratea caribaea Urban | Pristimera caribaea | Celastraceae
|