Houstonia asperuloides Brandegee, 1891 species accepted

Houstonia correlliae (W.H.Lewis) Terrell species accepted

Hedyotis longifolia var. ciliolata (Torr.) Mohlenbr. variety synonym

Hedyotis caerulea var. patens Ellis variety synonym

Oldenlandia patens (Elliott) Chapm. species synonym

Oldenlandia minima (Beck) A.Gray species synonym

Bouvardia chlorantha (Bertol.) Bertol. ex Schult. & Schult.f. species synonym

Houstonia polypremoides var. bigelowii Greenm. variety synonym

Hedyotis correlliae W.H.Lewis species synonym

Hedyotis polypremoides var. bigelowii Greenm. variety synonym

Hedyotis veronicaefolia Steud. species synonym

Hedyotis acerosa var. bigelowii (Greenm.) W.H.Lewis variety synonym

Hedyotis palmeri (A.Gray) W.H.Lewis species synonym

Hedyotis crassifolia f. albiflora (Standl.) W.H.Lewis form synonym

Hedyotis caerulea var. minima (Beck) Fosberg variety synonym

Hedyotis minima (Beck) Torr. & A.Gray species synonym

Hedyotis caerulea var. minor (Michx.) Torr. & A.Gray variety synonym

Ereicoctis crassifolia Kuntze species synonym

Oldenlandia rubra (Cav.) A.Gray species synonym

Hedyotis rubra (Cav.) A.Gray species synonym

Hedyotis humifusa Engelm. ex A.Gray species synonym

Oldenlandia humifusa (Engelm. ex A.Gray) A.Gray species synonym

Panetos rotundifolius (Michx.) Nieuwl. species synonym

Hedyotis procumbens var. hirsuta W.H.Lewis variety synonym

Hedyotis veronicifolia Steud. species synonym

Hedyotis procumbens (Walter ex J.F.Gmel.) Fosberg species synonym

Hedyotis cervantesii Kunth species synonym

Hedyotis pygmaea Roem. & Schult. species synonym

Ereicoctis cervantesii Kuntze species synonym

Hedyotis wrightii (A.Gray) Fosberg species synonym

Hedyotis croftiae (Britton & Rusby) Shinners species synonym

Hedyotis michauxii Fosberg species synonym

Hedyotis michauxii f. alba (Alexander) Fosberg form synonym

Chamisme longifolia (Gaertn.) Nieuwl. species synonym

Oldenlandia purpurea var. longifolia (Gaertn.) A.Gray variety synonym

Hedyotis purpurea var. longifolia (Gaertn.) Fosberg variety synonym

Oldenlandia purpurea (L.) A.Gray species synonym

Chamisme purpurea (L.) Nieuwl. species synonym

Knoxia purpurea (L.) Lam. ex Poir. species synonym

Hedyotis sharpii (Terrell) G.L.Nesom species synonym

Hedyotis ouachitana E.B.Sm. species synonym

Hedyotis subviscosa (C.Wright ex A.Gray) Shinners species synonym

Oldenlandia subviscosa C.Wright ex A.Gray species synonym

Hedyotis caerulea f. benkei Fosberg form synonym

Hedyotis caerulea f. albiflora (Millsp.) Fosberg form synonym

Oldenlandia caerulea var. patens (Elliott) M.Gómez variety synonym

Hedyotis caerulea var. faxonorum (Pease & A.H.Moore) Fosberg variety synonym

Hedyotis gentianoides Endl. species synonym

Hedyotis crassifolia var. micrantha Shinners variety synonym

Hedyotis australis W.H.Lewis & D.W.Moore species synonym

Hedyotis acerosa A.Gray species synonym

Ereicoctis acerosa (A.Gray) Kuntze species synonym

Oldenlandia acerosa (A.Gray) A.Gray species synonym

Mallostoma acerosum (A.Gray) Hemsl. species synonym

Hedyotis purpurea var. setiscaphia (L.G.Carr) Fosberg variety synonym

Hedyotis purpurea var. ciliolata (Torr.) Fosberg variety synonym

Hedyotis canadensis (Willd.) Fosberg species synonym

Chamisme ciliolata (Torr.) Nieuwl. species synonym

Hedyotis correllii W.H.Lewis species synonym

Hedyotis greenmanii Fosberg ex Shinners species synonym

Hedyotis teretifolia (Terrell) G.L.Nesom species synonym

Hedyotis macvaughii Terrell species synonym

Hedyotis taylorae Fosberg ex Shinners species synonym

Hedyotis rosea Raf. species synonym

Hedyotis minima f. albiflora Lathrop form synonym

Hedyotis sinaloae W.H.Lewis species synonym

Hedyotis vegrandis W.H.Lewis species synonym

Hedyotis spellenbergii G.L.Nesom & Vorobik species synonym

Houstonia stenophylla species accepted

Hedyotis greenmanii Fosberg species synonym

Hedyotis pumila Willd. ex Roem. & Schult. species heterotypic synonym

Houstonia salenia A.Heller species accepted

Houstonia reticulata Raf. species doubtful

Houstonia pygnaea C.H.Mull. & M.T.Müll. species synonym

Houstonia latifolia Willd. ex Roem. & Schult. species synonym

Houstonia geniculata Raf. species synonym

Houstonia crocea Schübl. species accepted

Houstonia coerulea var. toxonorum Stevens, 1910 variety synonym

Houstonia coerulea var. elatior (Michx.) Pursh variety synonym

Houstonia chlorantha Bertol. species doubtful

Houstonia caerulea f. albiflora Millsp. form synonym

Houstonia biloba Raf. species doubtful

Houstonia prostrata var. prostrata variety synonym

Oldenlandia serpyllifolia (Michx.) A.Gray species heterotypic synonym

Houstonia ochroleuca Raf. species doubtful

Oldenlandia caerulea (L.) A.Gray species heterotypic synonym

Oldenlandia rotundifolia (Michx.) A.Gray species heterotypic synonym

Hedyotis longifolia var. ciliolata (Torrey) B.Boivin variety synonym

Houstonia palmeri A.Gray species accepted

Houstonia pusilla Schoepf species accepted

Houstonia linnaei var. minor Michx. variety synonym

Houstonia minima Beck species synonym

Houstonia pusilla f. rosea Steyerm. form synonym

Houstonia minor Britton species synonym

Houstonia caerulea var. minor (Michx.) Pursh variety synonym

Houstonia pusilla f. albiflora (Millsp.) Fosberg form synonym

Houstonia patens Elliott species synonym

Houstonia rubra Cav. species accepted

Houstonia saxicola Eastw. species synonym

Houstonia humifusa (Engelm. ex A.Gray) A.Gray species accepted

Houstonia procumbens (Walter ex J.F.Gmel.) Standl. species accepted

Anotis rotundifolia DC. species synonym

Houstonia rotundifolia Michx. species synonym

Houstonia procumbens var. hirsuta (W.H.Lewis) D.B.Ward variety synonym

Poiretia procumbens Walter ex J.F.Gmel. species synonym

Houstonia wrightii A.Gray species accepted

Anotis cervantesii DC. species synonym

Houstonia croftiae Britton & Rusby species accepted

Houstonia serpyllifolia Michx. species accepted

Houstonia serpyllifolia f. alba Alexander form synonym

Anotis serpyllifolia (Michx.) G.Don species synonym

Houstonia tenella Pursh species synonym

Anotis tenella (Pursh) G.Don species synonym

Houstonia longifolia Gaertn. species accepted

Houstonia purpurea var. longifolia (Gaertn.) A.Gray variety synonym

Houstonia purpurea L. species accepted

Anotis purpurea (L.) G.Don species synonym

Houstonia sharpii Terrell species accepted

Houstonia ouachitana (E.B.Sm.) Terrell species accepted

Houstonia subviscosa (C.Wright ex A.Gray) A.Gray species accepted

Houstonia caerulea L. species accepted

Houstonia faxonorum (Pease & A.H.Moore) Fernald species synonym

Anotis gentianoides (Endl.) Walp. species synonym

Houstonia caerulea var. elatior (Michx.) Pursh variety synonym

Houstonia grandiflora Raf. species synonym

Houstonia caerulea var. faxonorum Pease & A.H.Moore variety synonym

Anotis coerulea (L.) G.Don species synonym

Houstonia caerulea var. piersii Barbour variety synonym

Poiretia erecta J.F.Gmel. species synonym

Houstonia linnaei Michx. species synonym

Houstonia caerulea var. toxonorum Stevens variety synonym

Houstonia linnaei var. elatior Michx. variety synonym

Houstonia micrantha (Shinners) Terrell species accepted

Houstonia acerosa (A.Gray) Benth. & Hook.f. species accepted

Houstonia canadensis Willd. ex Roem. & Schult. species doubtful

Houstonia setiscaphia L.G.Carr species synonym

Houstonia oblongifolia Raf. species synonym

Houstonia purpurea var. ciliolata (Torr.) A.Gray variety synonym

Houstonia canadensis var. setiscaphia (L.G.Carr) C.F.Reed variety synonym

Houstonia obtusifolia Raf. species synonym

Houstonia heterophylla Raf. species synonym

Houstonia longifolia var. ciliolata (Torr.) Alph.Wood variety synonym

Houstonia ciliolata Torr. species synonym

Houstonia correllii (W.H.Lewis) Terrell species accepted

Houstonia parviflora Holz. ex Greenm. species accepted

Houstonia teretifolia Terrell species accepted

Houstonia macvaughii (Terrell) Govaerts ex Borhidi species accepted

Houstonia rosea (Raf.) Terrell species accepted

Houstonia minor var. pusilla (A.Gray) Small variety synonym

Houstonia patens var. pusilla A.Gray variety synonym

Houstonia pygmaea C.H.Mull. & M.T.Mull. species synonym

Houstonia prostrata Brandegee species accepted

Houstonia prostrata var. parvula (Brandegee) Wiggins variety synonym

Houstonia parvula Brandegee species synonym

Houstonia spellenbergii (G.L.Nesom & Vorobik) Terrell species accepted

Hedyotis longifolia (Gaertn.) Hook. species heterotypic synonym

Hedyotis taylorae Fosberg species homotypic synonym

Hedyotis geniculata Raf. species heterotypic synonym

Hedyotis serpyllifolia (Michx.) Torr. & A.Gray species heterotypic synonym

Houstonia purpurea f. purpurea form synonym

Hedyotis palmeri var. muzquizana B.L.Turner variety synonym

Hedyotis tayloriae Fosberg species synonym

Hedyotis brachiata Miq. ex Hook.f. species heterotypic synonym

Houstonia caerulea f. caerulea form synonym

Houstonia macrosepala Nutt. ex Torr. & A.Gray, 1841 species accepted

Houstonia pusilla f. albiflora Standl. form synonym

Houstonia nuttalliana Fosberg species doubtful

Houstonia humifusa Hemsl. species heterotypic synonym

Houstonia canadensis Willd. species accepted

Hedyotis caerulea (L.) Hook. species heterotypic synonym

Houstonia serpyllifolia Graham species heterotypic synonym

Houstonia cervantesii Terrell species doubtful

Hedyotis purpurea (L.) Torr. & A.Gray species heterotypic synonym

Houstonia caerulea var. caerulea variety synonym

Hedyotis crassifolia Raf. species heterotypic synonym

Anotis caerulea (L.) G.Don species synonym

Hedyotis pygmaea Willd. species synonym

Anotis gentianoides Endl., 1847 species synonym

Houstonia longifolia var. ciliolata (Torr.) B.Boivin, 1968 variety synonym

Houstonia pusilla J.F.Gmel. species heterotypic synonym

Hedyotis rotundifolia (DC.) Torr. & A.Gray species heterotypic synonym

Bouvardia chlorantha (Bertol.) Bertol. species homotypic synonym

Hedyotis pumila Willd. species homotypic synonym

Hedyotis humifusa Engelm. species homotypic synonym

Hedyotis brachiata Miq. species homotypic synonym

Oldenlandia subviscosa C.Wright species homotypic synonym

Houstonia macvaughii (Terrell) Govaerts species homotypic synonym

Poiretia procumbens Walter species homotypic synonym

Houstonia parviflora Holz. species homotypic synonym

Knoxia purpurea (L.) Lam. species synonym

Houstonia tenuifolia Nuttall ex A.Gray species synonym

Houstonia ciliata Rafinesque species synonym

Anotis ciliolata (Torrey) G.Don species synonym