Rubiaceae | |
Houstonia caerulea fo. albiflora
| Millsp. | Bull. West Virginia Agric. Exp. Sta. 375 | 1892 |
Rubiaceae | |
Houstonia caerulea fo. caerulea
| | | |
Rubiaceae | |
Houstonia caerulea var. caerulea
| | | |
Rubiaceae | |
Houstonia caerulea var. elatior
| (Michx.) Pursh | Fl. Amer. Sept. 1: 106 | 1814 [1813] |
Rubiaceae | |
Houstonia caerulea var. faxonorum
| Pease & A.H. Moore | Rhodora 9(107): 210 | 1907 |
Rubiaceae | |
Houstonia caerulea var. minor
| (Michx.) Pursh | Fl. Amer. Sept. 1: 106 | 1814 [1813] |
Rubiaceae | |
Houstonia caerulea var. piersii
| J.H. Barbour | Proc. & Trans. Nova Scotian Inst. Sci. 11: 558 | 1908 |
Rubiaceae | |
Houstonia caerulea var. toxonorum
| Stevens | Ill. Guide Fl. Pl. 582 | 1910 |